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Monograph
A revision of Xylopia L. (Annonaceae): the species of Tropical Africa
expand article infoDavid M. Johnson, Nancy A. Murray
‡ Ohio Wesleyan University, Delaware, United States of America
Open Access

Abstract

A revision of the 45 species of the pantropical genus Xylopia in Tropical Africa includes descriptions of six new species and a new section of the genus. The fruits and seeds of Xylopia show specializations that promote vertebrate dispersal, primarily by hornbills and monkeys. Over half of the African species have an Area of Occupancy (AOO) less than 80 km2, suggesting that they are in need of protection. African species are classified into five sections. Section Neoxylopia , with four species, is centered in the Guineo-Congolian Region and includes X. globosa sp. nov. Section Ancistropetala, with three species, occurs in the same region. Both of these sections are endemic to Africa. Section Xylopia, which extends to Madagascar and the American tropics, has only a single species in Africa, X. aethiopica. The three species of section Verdcourtia sect. nov. are restricted to the East African coast and Madagascar. The largest number of African species, (34) belong to section Stenoxylopia, in which the seeds lack the arils found in the other sections and instead have a fleshy sarcotesta. Section Stenoxylopia is divided into two informal groups, one centered in eastern and southern Africa (X. odoratissima group) and the other centered in the wetter forests of western and central Africa (X. acutiflora group). Five new species are described in section Stenoxylopia: Xylopia nilotica sp. nov. from Sudan, South Sudan, and Uganda, Xylopia calva sp. nov. from Nigeria and Cameroon, which is allied to X. phloiodora, and Xylopia monticola sp. nov. from Nigeria and Cameroon, X. piratae sp. nov. from Ivory Coast and Ghana, and X. unguiculata sp. nov. from Gabon. The latter three species are segregates of the former Xylopia acutiflora s. l. One new combination is made at the species level, X. shirensis comb. nov. Keys, descriptions, illustrations, distribution maps, and an index to numbered collections document diversity and assist with species identification. The name Unona oliveriana Baill. was found to pre-date the name Unona lepidota Oliv., requiring the combination Meiocarpidium oliverianum comb. nov.

Keywords

Xylopia, pantropical Annonaceae, Tropical Africa, long distance dispersal, bird/monkey syndrome, X. aethiopica, conservation, new species

Introduction

Xylopia L. is unique within the early-divergent angiosperm family Annonaceae in its pantropical distribution and, with 160–180 species worldwide, it is the second largest genus in the family. The plants bear distinctive fruits composed of clusters of fingerlike monocarps, which dehisce when ripe, displaying their seeds against an endocarp of contrasting color. In Africa, birds and monkeys play an important role in the dispersal of the seeds (Whitney et al. 1998, Poulsen et al. 2001, Koné et al. 2008), underscoring the interdependence of the plants and their vertebrate dispersers in tropical forest systems. The fruits of one widespread African species, Xylopia aethiopica (Dun.) A. Rich., are the source of a spice and medicine, which has been used since antiquity (Avicenna 1544, Matthioli 1565, Dunal 1817, Burkill 1985).

Xylopia is classified, together with its sister group Artabotrys R. Br., in the tribe Xylopieae of subfamily Annonoideae (Chatrou et al. 2012). Evidence from four molecular markers and seed morphology data points to the origin and early diversification of Xylopia in tropical Africa (Thomas et al. 2015, Stull et al. 2017). Thomas et al. (2015) also provided a divergence time estimate for the separation of Xylopia and Artabotrys at 54.6–63.2 million years ago (Mya), as well as evidence of rapid radiation of Xylopia into four clades at about 30 Mya, 27 Mya, and 23 Mya, respectively. These divergence times post-date the breakup of the Gondwanan supercontinent, suggesting that the pantropical distribution of Xylopia was established by long-distance dispersal rather than by tectonic movement of major Southern Hemisphere landmasses (Stull et al. 2017).

Species from all four major clades are present in Africa, concomitant with the widest range of morphological and ecological diversity found in the genus. Included in the first diverging clade (Fig. 1) of Xylopia are species with brushlike arils, which comprise section Neoxylopia Engl. & Diels. Diverging next are all species with fimbriate arils, which comprise section Ancistropetala (Engl. & Diels) D. M. Johnson & N. A. Murray. Both of these sections are exclusively African. The remaining species are divided into a clade with bilobed arils and a clade with various aril types or lacking arils entirely. Bilobed arils define section Xylopia, a section present in tropical America, Madagascar, the Mascarene Islands, and with a single species, X. aethiopica, present in Africa. Species of the fourth clade, which were placed in section Stenoxylopia Engl. & Diels, are present in Africa, Madagascar, and Australasia, and form the largest African group (Stull et al. 2017).

Figure 1. 

Maximum clade credibility tree for Xylopia. Tree obtained from Bayesian analysis of the four-marker data set for 44 Xylopia species, from Stull et al. (2017), showing geographic distribution, major clades, and relationship of named sections. Species of the first diverging subclade of the Stenoxylopia clade, X. mwasumbii, X. lukei, and X. sp. aff. sahafariensis, are placed in this revision into a new section, sect. Verdcourtia. Figure reproduced with permission of the American Society of Plant Taxonomists.

In 1901, Engler and Diels recognized 18 African species of Xylopia, which they classified among four sections primarily on the basis of fruit and seed characters. Development of Xylopia taxonomy in Africa then proceeded through floras, e.g. Davy (1926), Andrews (1950), Boutique (1951b), Tisserant and Sillans (1953), Keay (1954–1958), Robson (1960), Paiva (1966), Le Thomas (1969), and Verdcourt (1971b). These works provided descriptions and identification keys for plants in most of the individual African countries where Xylopia occurs, but did not agree in their taxonomic concepts. We have made incremental contributions to the taxonomy through descriptions of new species (e.g. Johnson et al. 1999, 2017) and through a new infrageneric classification (Stull et al. 2017). This revision of tropical African species has two goals: to integrate and update taxonomic understanding of Xylopia in Africa and to provide a framework for the study of diversity and biology of Xylopia across its global distribution.

Taxonomic history

Xylopia was initially conceived as an exclusively American group. The name Xylopicrum, an appellation denoting bitter wood, was proposed by Patrick Browne in 1756 for two species of trees from Jamaica. In 1759, Linnaeus shortened the generic name to Xylopia and proposed the names Xylopia muricata L. and Xylopia glabra L. for these Jamaican species. Adanson (1763) returned to Browne’s form of the generic name, with the orthographic change to Xylopicron, and Crantz (1766) subsequently made combinations using the same epithets but Adanson’s form of the name.

The written record of Xylopia from Africa, however, far preceded the formalization of binomial nomenclature by Linnaeus. The first record of a species now placed in Xylopia likely comes from seeds and fruits described in the work of Avicenna (980–1037). In Europe, Matthioli (1565) provided the earliest known illustration of a Xylopia, which he called Piper AEthiopicum (p. 575: Fig. 2). [Note: Dunal (1817) cited the 1544 edition of Matthioli’s work as having an illustration on p. 434, but Stephen Greenberg of the National Library of Medicine reports that the only entry on p. 434 of the work is for sect. 99 concerning “Pietra Asia,” and he added that there is no mention of Piper aethiopicum in the work; there was neither description nor illustration of the plant in the 1554, 1558, or 1560 editions of the work that we examined in digital copy form.] The woodcut illustration in Matthioli (1565) shows a branch bearing five fruits, and the plant is readily recognizable as the plant now known as Xylopia aethiopica (Fig. 2). Matthioli was also the first to link his Piper aethiopicum with the plant referred to as “piper nigrorum” and “hab zelim, id est, grano zelim” by Serapion (Latin translation 1531), which was in turn linked to the plant called “granum azelem” in a Latin translation of Avicenna (1544). Matthioli added that the fruits came through Alexandria in Egypt along with other spices: “Affertur ex Alexandria Aegypticum cum alijs aromatis.” The Matthioli woodcut was copied and modified in various ways over the next 200 years. During this time the name of the plant became standardized as Piper aethiopicum.

Figure 2. 

Plate of Piper AEthiopicum from Matthioli (1565), the earliest known illustration of Xylopia aethiopica.

Oddly, Linnaeus completely ignored the African plant in his works. Gatherings of plants that included X. aethiopica first received a post-Linnaean Latin binomial from Lamarck (1785), who proposed the name Uvaria aromatica Lam. in recognition of the spicy fruits. Lamarck’s species was founded upon a mixture of materials from varied geographic sources, including not only references to pre-Linnean herbals but also to a specimen from Peru collected by Joseph de Jussieu and others from French Guiana and possibly Mauritius collected by Fusée Aublet.

Two other early generic names proposed by Necker (1790) are connected with Xylopia. In his description of Krockeria Necker made reference to the plant identified by Aublet (1775) as “Waria zeylanica,” a mis-print for Uvaria zeylanica L. Aublet’s plant had already been incorporated at the species level into Uvaria aromatica by Lamarck, but was later separated out by Willdenow (1799), who used Guianan material described by Aublet as the type of his Unona concolor Willd. The second Necker name, Bulliarda Necker, appears to be a re-naming of the genus Unona L. f. (Linnaeus 1782), as evidenced by details of the description (umbellate fruits, fruits 2-seeded) that appear in the original description of Unona. Jussieu (1810) adopted that interpretation.

In 1817, Dunal’s Monographie de la famille des Anonacées provided the first monograph of the family. Dunal adopted Xylopia, the shortened form of the generic name used by Linnaeus, recognizing eight tropical American species in the genus, most of them Xylopia species in the modern sense but also including two species now placed in Anaxagorea A.St.-Hil. Dunal distinguished Xylopia from the other Annonaceae genera by the combination of campanulate calyx, outer petals broader than the inner, and short-stipitate compressed monocarps. For unexplained reasons, Dunal transferred Lamarck’s Uvaria aromatica to the genus Unona, which had been proposed by Linnaeus (1782) for a plant he named Unona discreta L. f., collected by Dahlberg in Suriname. Dunal also distinguished the African material of Lamarck’s Uvaria aromatica as Unona aethiopica Dun. and Jussieu’s plant from Peru as Unona lucida Dun. The only elements that then remained with Lamarck’s Uvaria aromatica were plants identified in Aublet (1775) as Waria zeylanica. Dunal expanded the genus Unona to encompass a heterogeneous grouping of 35 species from Africa, Asia, and the Americas. The plates in Dunal’s work clearly illustrate, however, similarities between the species he placed in Xylopia and some of those in Unona. He himself recognized that the distinctions between Xylopia and Unona were unclear, noting, at the end of the description of Xylopia nitida Dun., “Confert Unona xylopioides.” Brown (1818) followed Dunal’s generic description of Unona, reporting plants collected by Christian Smith from the Congo region to be “very nearly related to Piper AEthiopicum of the shops, the Unona aethiopica and, perhaps also Unona aromatica of Dunal.”

The work of Richard, the author for the “Anonaceae” in Guillemin et al. (1831), becomes important at this juncture. Richard argued that the genera Asimina Adans., Porcelia Ruiz & Pavon, and Unona accepted by Dunal should all be reduced to taxonomic synonyms of Uvaria. Accordingly, he moved Unona aethiopica to the genus Uvaria and described an additional African species of Uvaria, U. parviflora. Alphonse de Candolle (1832) did not follow Richard’s generic concepts but instead moved in the opposite direction. He distinguished 17 genera in the family and expanded Xylopia to ten tropical American species. For Dunal’s Unona aethiopica, Candolle proposed a new genus, Habzelia A. DC., and transferred to this new genus Unona aethiopica from Africa, Unona discreta from tropical America, and Xylopia undulata Palisot de Beauvois, also from Tropical Africa, and described a new species, Habzelia obtusifolia A. DC., from Cuba. Candolle distinguished Habzelia from Unona by its arillate seeds and striate, glabrous, and irregularly moniliform fruits, and from Xylopia by its more elongate and scarcely swollen carpels (i.e. the monocarps), and the convex rather than concave torus [“….toroque verosimiliter non concavo.”]. In the same work, Candolle also proposed the genus Coelocline A. DC., noting its similarities to Habzelia, Unona, and Xylopia but distinguishing it on the basis of the concave torus, to which the generic name alludes. Only one species, Unona acutiflora Dunal, was placed in Coelocline with certainty, but Candolle proposed new combinations for C. parviflora (A. Rich.) A. DC., C. oxypetala (Dun.) A. DC., C. polycarpa (Dun.) A. DC., and C. lucida (Dun.) A. DC. as Species dubiae. These were African species except for C. lucida from South America. In summary, Candolle adopted a much narrower concept of Unona than that of Dunal, restricting it to five species of Asian Annonaceae now classified as species of Desmos Lour. and Dasymaschalon Dalla-Torre & Harms, and two species from Madagascar now placed in Uvaria. This narrower concept circumscribed Unona in a way that excluded the type of the genus, Unona discreta, which Candolle placed under Habzelia.

Richard (1841) was the first author to extend the concept of the genus Xylopia to plants from Africa, and, in the process, he circumscribed the genus in what would come to be its modern sense. He rejected the genera Habzelia and Coelocline, transferred species from these genera to Xylopia, namely X. acutiflora (Dun.) A. Rich., X. aethiopica (Dun.) A. Rich., and X. obtusifolia (A. DC.) A. Rich., and described the new species X. cubensis A. Rich. His concept was then adopted and expanded for Africa by Bentham (1862), Baillon (1864), and Oliver (1868), and, for Asia, by Hooker and Thomson (1855, 1872). Xylopia, the Linnaean form of the generic name, was used by these and subsequent authors for most of the 19th century. Kuntze (1891, 1903), however, attempted to re-assert the use of the earlier name Xylopicrum, making many new combinations. In the 20th century the name Xylopia was conserved over Xylopicrum (see Lanjouw et al. 1956). A pantropical generic concept of the genus was now in place, but taxonomic work on the genus generally proceeded separately in the Americas, Asia, and Africa.

In Africa, the dimensions of Xylopia diversity were rapidly defined between 1899 and 1936 through multiple works of Engler, Diels, De Wildeman and Durand, Mildbraed, and Exell. The major work of this period was the monograph of African Annonaceae by Engler and Diels (1901), which provided a subgeneric classification of Xylopia, dividing it into four sections. Also important was Safford’s (1912) discovery that the type species of the genus Unona was in fact a Xylopia; the combination Xylopia discreta was later made by Sprague and Hutchinson (1916). Unona was now regarded as a taxonomic synonym of Xylopia and no longer a name for Desmos and its allies. Local floristic works adding many species to the genus followed, many of them recently incorporated into the sectional classification of Stull et al. (2017).

Methods

We studied over 2000 collections of African Xylopia from the following herbaria (acronyms from Thiers 2017): A, B, BISH, BM, BNRH, BR, COI, DSM, EA, F, FHO, FI-T, FI-W, G, GH, GOET, HBG, K, L, LISC, LISU, LMA, LYD, M, MA, MO, NHT, NY, P, PH, PR, PRC, PRE, RSA, TFD, U, US, W, WAG, WU, and YF. Fieldwork was carried out in eastern Tanzania from January to July 1996. All measurements of plant parts, unless otherwise indicated, are based on dried herbarium specimens. Measurements of fine details of indument, flower parts, and seeds were made using an ocular micrometer mounted on a stereomicroscope and measuring to the nearest 0.1 mm. Publication dates, when unclear, were obtained from the Taxonomic Literature II (TL-II) series (Stafleu and Cowan 1976 and succeeding volumes). Specimen citations are organized geographically from west to east, and then south across the African continent. Within countries, specimens are cited alphabetically by collector or, in the case of some larger countries, alphabetically by political subdivision and then alphabetically by collector.

Maps were generated from herbarium specimen data. In cases where latitude and longitude coordinates were not provided on the specimen label, we determined the coordinates from published maps. Coordinates were assembled in an Excel spreadsheet for each species, and imported into ArcGIS to produce the final maps. Summary maps of species diversity per 1° × 1° grid cell, and of the distribution of individual sections and two informal groups of species, were produced using the individual species maps in ArcGIS. We also summarized species diversity and endemism by biogeographic region and subregion, and superimposed the numbers on a map published by Linder et al. (2012). The individual species maps, generated with ArcGIS, were also used to calculate Extent of Occurrence (EOO) and Area of Occupancy (AOO), following IUCN Red List guidelines (IUCN Species Survival Commission 2012). Cell size for AOO was 2 × 2 km.

Morphology and anatomy

Habit. African xylopias span the size range for the genus and likely for the entire family. Forest species, such as Xylopia staudtii Engl. & Diels, are canopy trees reaching 50 m in height. Many species of tree habit form buttresses at the base of the trunk. In section Neoxylopia, X. africana (Benth.) Oliv., X. rubescens Oliv., and X. staudtii, form conspicuous stilt roots; in X. staudtii, the stilt roots bear peglike pneumatophores (Jeník 1970). At the other size extreme in the genus are dryland shrubs such as X. collina Diels and X. tomentosa Exell, which may be multi-stemmed and flower when only 0.5 m tall. A unique growth form is found in Xylopia piratae D. M. Johnson & N. A. Murray, from West Africa, which is described by most collectors as a liana. Herbarium material of this species exhibits a marked tendency for ultimate branches to be short and divergent from the larger branch axis at nearly right angles. No specialized holdfast structures, such as the hook-shaped inflorescence branches of Artabotrys or the twining short-shoots of Fissistigma and Monanthotaxis, are present, so the shoots may simply sprawl upon surrounding vegetation.

All Xylopia species examined have spiral phyllotaxis of the main axis giving rise to a spiral arrangement of the primary branches (Johnson 2003, Hallé 2004). Leaf arrangement on the lateral branches is always distichous. In sect. Verdcourtia D. M. Johnson & N. A. Murray (see pp. 88-89), sect. Stenoxylopia, and some species of sect. Neoxylopia, collateral buds are present, usually two per node but occasionally three. The buds grow out simultaneously, producing two or three branches from the same node (Fries 1919, 1959, Johnson 2003). This pattern produces a “messy” tree architecture that differs from the regularly spaced branches typical of other Xylopia species and many other Annonaceae as well (Spruce 1861, Hallé et al. 1978, Johnson 2003, Hallé 2004). Indurated bud scales were seen in X. arenaria Engl., X. collina, and X. elliotii Engl. & Diels, all species of seasonally dry habitats, which in the case of X. collina may also be subjected to fire. Twigs in most species are initially pubescent, rarely glabrous, but at length, the hairs are lost and the longitudinal wrinkling characteristic of Annonaceae twigs develops.

Bark and wood anatomy. Where reported, the bark is most often described as smooth and light gray to brown. In contrast, in X. congolensis De Wild., X. pynaertii De Wild., X. quintasii Engl. & Diels, X. staudtii, and X. villosa Chipp, the bark is described as rough and scaly. The upper bark of X. pynaertii is red and flakes and peels away from the trunk, a unique feature among African species. Irregular exfoliating patches may develop on otherwise smooth bark in X. mwasumbii D. M. Johnson, X. odoratissima Welw. ex Oliv., X. gracilipes D. M. Johnson & N. A. Murray, and X. nilotica D. M. Johnson & N. A. Murray. Fine longitudinal cracks or fissures in the bark have been reported for X. aethiopica, X. gilbertii Boutique, X. toussaintii Boutique, X. letestui Pellegr., X. paniculata Exell, X. phloiodora Mildbr., and X. tanganyikensis D. M. Johnson. Collectors frequently remark on the aromatic character of the cut bark, and the species X. phloiodora is named for that property.

Koek-Noorman and Westra (2012) surveyed Annonaceae wood anatomy, including 24 species of Xylopia, five of them African. The wood of Xylopia species surveyed had the anatomical structure characteristic of the Annonaceae, namely wide and high parenchyma rays and closely spaced tangential parenchyma bands. Xylopia and Artabotrys R. Br. have largely similar wood, showing relatively large solitary vessels, often with a single vessel in contact with the parenchyma ray on either side of it, or, alternatively, vessels in small radial multiples with widely spaced tangential parenchyma bands. A major departure was found in two tropical American species of Xylopia, X. peruviana R. E. Fr. and X. cuspidata Diels: their vessels have relatively small diameters and the tangential parenchyma bands are more numerous and closer together. The African species surveyed represented three of the four major Xylopia clades, suggesting that wood structure has largely been conserved evolutionarily across the genus.

Leaves. Leaves of Xylopia are always distichous, exstipulate, simple, and entire, as is characteristic of the family. The leaf blades are commonly lanceolate, elliptic, or oblong, and chartaceous to subcoriaceous. In African species, the blades most often bear inconspicuous hairs, but in X. hypolampra Mildbr., X. letestui, X. talbotii Exell, and X. villosa, the blades are densely pubescent on the abaxial surface. The indument of the leaf is most pronounced on the abaxial surface in X. hypolampra, so named for the shining sericeous covering formed by the hairs. The secondary vein pattern is brochidodromous; in some species, such as X. quintasii, the loops are distinctly closed and conspicuous, while in others, such as X. odoratissima, the secondary veins may branch near the leaf margin and form only weak connections with the succeeding secondary vein. The secondary veins can be strongly arcuate in some species, such as X. paniculata Exell. The petiole is usually short, less than 1/5 of the length of the blade, and flattened to canaliculate on the adaxial surface.

Leaf anatomy was studied by Kramer (1969), who summarized the anatomical features as the following: small to medium-sized druses present in nearly every cell of the upper and lower epidermis, venation reticulate, midvein simple with a single arc of vascular tissue usually divided into more or less distinct bundles, palisade mesophyll comprised of 2–3 cell layers, and bicellular trichomes that are more numerous on the abaxial surface. He noted several anatomical features that were variable in the genus: presence of a multiple epidermis or hypodermis, sclereids in the mesophyll, papillate lower epidermis, and sculpturing of the internal walls of the basal cells of the trichomes, the latter only occurring in some Neotropical species. Both a uniseriate epidermis and a multiseriate epidermis were found in African and in non-African species. Mesophyll sclereids, in contrast, were found exclusively in Paleotropical species, including X. acutiflora, X. letestui, X. quintasii, X. piratae, and X. thomsonii Oliv. from Africa. Xylopia letestui was unique among the Xylopia species sampled in having multicellular papillae on the lower leaf surfaces and septate apical cells of the bicellular trichomes.

Inflorescences. Inflorescences in Xylopia are always axillary, sometimes arising from the axils of fallen leaves. Cauliflory was not observed in any African species. The rhipidiate inflorescence described for the Neotropical species X. brasiliensis by Fries (1919) is only evident in X. aethiopica; both are members of section Xylopia. In many species the inflorescences consist of pedicels that arise independently side-by-side from the leaf axil; in others, there may be one common peduncle from which some or all pedicels of the axil arise. In species such as X. calva and X. phloiodora the peduncle may be broader than long and somewhat embedded in the stem. The peduncle always lacks bracts; the pedicels bear 2–6 small (0.5–7.4 mm long) bracts that may be caducous or persistent, somewhat clasping, and usually pubescent on the abaxial surface. The largest bracts occur in the closely related species X. villosa (up to 7.4 mm) and X. letestui (up to 6 mm). Bracts in species such as X. acutiflora and X. thomsonii number 3–6 per pedicel and are often imbricate. In these species, the pedicel superficially resembles a grass spikelet, and the bracts often persist into the fruiting stage. The number of flowers per inflorescence is typically 1–2, occasionally up to five. That number is exceeded in the following species: Xylopia holtzii Engl. and X. shirensis (Engl. & Diels) D. M. Johnson & N. A. Murray, with up to 6 flowers per inflorescence, X. aethiopica and X. quintasii with up to 7, X. tomentosa and X. villosa with up to 8, X. calva D. M. Johnson & N. A. Murray and X. phloiodora with up to 10, and X. katangensis De Wild. with up to 12. Exceptionally, in X. paniculata there are up to 32 flowers per inflorescence.

Flower buds in Xylopia are linear to ovoid. Because the petals lengthen early in development, the buds provide a reliable indicator of the ultimate shape of the petals. The petals of both whorls remain connivent until anthesis, when they spread apart in various ways. The apex of the bud may be acute to obtuse, and, in narrower buds, is often falciform at the apex.

Flowers. Xylopia flowers have the perianth format typical of Annonaceae, a single whorl of three sepals, a whorl of three outer petals, and a whorl of three inner petals borne on a flat or slightly concave receptacle. Perianth parts are valvate in aestivation within each whorl; the sepal bases are imbricate in a few species. The sepals are much shorter than the petals, often connate at the base to form a cuplike or bowl-shaped calyx, and coriaceous in texture. In most species, they remain erect or may spread slightly, but in X. longipetala De. Wild. & T. Durand they are completely reflexed. The outer petals are membranous to fleshy, and vary in shape from broadly ovate to linear, and from acute to rounded at the apex. The adaxial pubescence consists of finer and more erect hairs than are present on the abaxial surface, where the hairs tend to be longer, more appressed, and often yellow-brown to orange-brown in the dried condition. The base of the petal is concave and usually glabrous on both surfaces. The adaxial surface of the outer petal is shallowly concave but becomes ridged toward the apex where the petals are pressed together in bud above the inner petals; the abaxial surface often has a weak longitudinal ridge for the length of the petal.

In most species, the inner petals are slightly shorter and narrower than the outer petals. In X. thomsonii, it is common for the inner petals to be only ca. 2/3 of the length of the outer petals. The most pronounced difference in the lengths of outer and inner petals occurs in Xylopia rubescens, where the linear outer petals are ca. eight times the length of the ovate inner petals. Inner petal texture varies from coriaceous to fleshy for most species, but is subcoriaceous in X. piratae, chartaceous in X. staudtii, X. africana, X. globosa D. M. Johnson & N. A. Murray, X. katangensis, and X. wilwerthii De Wild. & T. Durand, chartaceous to membranous in X. longipetala, and membranous in X. tenuipetala D. M. Johnson & Goyder. The pubescence of the abaxial surface in inner petals resembles that of the adaxial surface, and both surfaces bear a longitudinal ridge. The base of the inner petal is concave and glabrous, and is more differentiated than the base of the outer petal, often with a transverse “heel” where the petal may be bent outward above a thinner basal claw of the petal, for example in X. tomentosa. In the case of X. aurantiiodora De Wild. & T. Durand, there is a distinct tooth that forms on the adaxial surface at this widest point. In several African species, the margins of the inner petals are differentiated toward the base. In sect. Ancistropetala, the petal base has thin inrolled glabrous margins, and, in the species X. gilbertii, X. flamignii Boutique, and X. toussaintii of sect. Stenoxylopia, the margins are thickened and knobby. These differentiated petal margins may represent food tissue for flower visitors as in, for example, Cymbopetalum Benth. (Murray 1993), or perhaps they are secretory, but no supporting field observations have been published.

Petal color typically ranges from pure white to pale yellow or cream-colored to pale orange, often with purple or red blotches around the pollination chamber aperture; the apex of the anther connective is often red as well. A limited number of variations occur. The flowers of X. mwasumbii and X. tenuipetala are tinted green at anthesis, and the flowers of X. collina and X. flamignii becoming dull red at maturity (Fig. 3). In X. rubescens, the long outer petals are yellow to orange, but the short inner petals are dark red. Flower color has not been reported for many species.

Petal orientation at anthesis is variable in African xylopias and determines the shape of the pollination chamber formed by the petals. In most species, the outer and inner petals separate at the beginning of anthesis, curving gradually outward at the base and then curving inward toward the apices, the petal bases alone forming the chamber (Fig. 3D, E, G). In species of sect. Neoxylopia, however, the petals hardly separate from one another and the entire corolla forms the chamber. In sect. Stenoxylopia, species including X. arenaria, X. collina, and X. tomentosa, have outer petals that remain erect, while the apices of the inner petals bend outward and extend horizontally through the gaps between the outer petals; the chamber is formed by the outer petals and the bases of the inner petals (Fig. 3H, I). In sect. Verdcourtia, it is the outer petals that bend outward perpendicular to the erect inner petals, and the inner petals in their entirety form the chamber (Fig. 3B).

Figure 3. 

Flowers of representative Xylopia species. A Flower from type collection of Xylopia globosa from Gabon B Xylopia tenuipetala from Mozambique C Xylopia quintasii from Gabon D Xylopia aethiopica from Gabon E Xylopia longipetala from Mali, representing a record for the country not otherwise documented F Xylopia piratae from Ivory Coast G Xylopia odoratissima from Zambia H Xylopia arenaria from Tanzania I Xylopia collina from Tanzania. A, D by Thomas L. P. Couvreur B by Frances Chase C by Ehoarn Bidault E by Philip Birnbaum F by Céline Pirat G by Warren McClelland H and I by D. M. Johnson.

The androecium of Xylopia is one of the most specialized in the Annonaceae, but also has a number of typical family characteristics. Most species have an androecium with a large number (60–200) of fertile stamens, the apex of the anther connective is short (0.1–0.4 mm), truncate or shieldlike in shape and overhanging the thecae, the filaments are short (0.2–0.6 mm), and the anthers have extrorse dehiscence. A trend toward fewer stamens is evident in section Verdcourtia, with stamen numbers ranging from ca. 65 in X. lukei D. M. Johnson & Goyder to as few as 40 in X. aurantiiodora and X. mwasumbii. The apex of the anther connective in species of sect. Ancistropetala is globose or conical and does not overhang the thecae, lending a pebbly appearance to the surface of the androecium, in contrast to the typical flat surface; in species of sect. Verdcourtia, the apices are rudimentary (≤0.1 mm long). Filaments exceeding 0.6 mm in length occur in several species: X. rubescens, X. africana, X. lukei, X. mwasumbii, X. tenuipetala, X. unguiculata D. M. Johnson & N. A. Murray, and X. calva. The anthers of Xylopia are transversely septate, the septa forming 4–14 locelli, each of which contains one pollen tetrad or a polyad of 5–6 coherent tetrads (Walker 1971); X. arenaria and X. collina were found to occasionally have up to 17–18 locelli and X. phloiodora characteristically has the anthers divided into 20–24 locelli. The walls of the septa are parenchymatous (Tsou and Johnson 2003) and are typically sturdy enough to withstand the tearing of the outer wall during anther dehiscence and thus are still visible in dehisced anthers.

The androecium of all species of Xylopia includes staminodes, which rarely contain rudimentary anther sacs. Both outer and inner staminodes are typically present in the same flower, a unique condition in the Annonaceae (van Heusden 1992). The outer staminodes are about the same length as fertile stamens but are usually wider and flattened all the way to the apex. The inner staminodes are more similar to fertile stamens in shape, sometimes with a flattened anther connective apex retained; they often adhere to the bases of the stigmas in dried specimens. In Africa, outer staminodes are absent in only two species, X. mwasumbii and X. tenuipetala, both members of section Verdcourtia, in which fertile stamen numbers are also reduced. Inner staminodes are absent in X. aurantiiodora and X. quintasii, and, probably, in X. congolensis and X. mildbraedii Diels as well. Occasional flowers of X. mwasumbii may have reduced numbers of locelli on the innermost stamens or lack inner staminodes. Staminodes are rare in Annonaceae, occurring in only seven genera (van Heusden 1992, Saunders 2010). The unique presence of both outer and inner staminodes in Xylopia probably represents an independent evolution of sterile stamens within the Annonaceae, as Xylopia is not closely allied to any of the other staminodial genera.

The most distinctive aspect of the androecium of Xylopia, however, is the cone on which the stamens are borne. In some species, the cone forms a chamber completely enclosing the ovaries, with a narrow aperture from which only the stigmas protrude; this is the “hollow torus” on which Candolle (1832) based his concept of the genus Coelocline. Kramer (1969) indicated that the cone was probably receptacular rather than staminal in origin, and Deroin (1989), in a study of floral cortical vascular systems in Annonaceae, followed this interpretation. Verdcourt (1971b) described the cone as “filaments articulated, sometimes partly united at the base and enclosing the gynoecium.” In an anatomical study of mature X. aromatica flowers, Dias et al. (1998) found that the cone surrounding the carpels was of mixed origin, consisting of fused sepals, petals, and stamen filaments but with the apical portion “exclusively formed by the fusion of the filaments, thus constituting a staminal tube.” In all species examined in this study, individual filaments are distinguishable on the cone, below the stamen abscission scars. In sect. Xylopia and in some species of sect. Stenoxylopia, the staminal cone is well developed and completely encloses the ovaries. In species of sect. Neoxylopia, sect. Verdcourtia, and most species of sect. Stenoxylopia, the cone is rudimentary and consists only of a low laciniate rim around the base of the ovaries, and, in the species of sect. Ancistropetala, the cone is completely absent. Remnants of the cone often persist into the fruiting stage, but are torn apart by the expansion of the torus as the fruit matures.

Xylopia pollen is shed in tetragonal tetrads or, in X. africana, the Asian species X. ferruginea (Hook. f. & Thoms.) Baill., and the Neotropical species X. brasiliensis and X. micans in polyads of about 5–6 individually discernible tetrads, with each tetrad or polyad in a separate compartment of the septate anther (Walker 1971). Walker (1971) described the individual grains as heteropolar, bilateral, catasulcate to cataulcerate, boat-shaped to triangular to disklike, with the long axis of 52–170 µm. The exine is smooth and microperforate in many species (Walker 1971, Le Thomas 1980, 1981), but verrucose in X. quintasii and so thin as to be nearly absent in species such as X. arenaria and X. holtzii (Tsou and Johnson 2003). Le Thomas (1980, 1981) described the structure of the pollen wall in X. aethiopica as consisting of a thick smooth continuous tectum over a granular infratectal layer (Bos 2198) and that the exine of X. staudtii (Letouzey 11854) was similar except for the greater fusion of the granules in the infratectal layer to form a “massive discontinuous basal layer in which their contours are no longer recognizable.” Doyle and Le Thomas (2012) later concluded that their previous interpretation of the infratectal granules as becoming fused needed to be re-examined as a possible case of reduced columellae.

The carpels in Xylopia are always separate and, in African species, vary in number from two in some flowers of X. tenuipetala to ca. 40 in X. aethiopica; no unisexual flowers were found, such as those described for the Asian species X. championii Hook. f. & Thoms. by Ratnayake et al. (2007). The carpels consist of a short, oblong, pubescent ovary surmounted by a relatively long filiform structure bearing the stigmatic surface but not differentiated into style and stigma. We refer to the entire structure as the stigma. In Xylopia, the stigmas are usually glabrous except for a tuft of hairs at the apex. They are connivent or free; when connivent, the stigmas drop as a group as they abscise from the ovaries at the end of anthesis. There is a large amount of exudate produced on the stigmas in species observed in the field and connivent stigmas are difficult to separate from each other in the dried condition. It is not clear whether there is also a cellular connection between the connivent stigmas. The exudate may be a pollinator reward, an aid to pollen germination or form an extragynoecial compitum, which has been shown to guide intercarpellary growth of pollen tubes in other Annonaceae (Lau et al. 2017). In the species of sect. Neoxylopia, the stigmas bear papillae or tubercles along their sides; in the case of X. rubescens, the tubercles are stalked (Le Thomas 1969, Plate 28, fig. 8). In sect. Ancistropetala, the stigmas are clavate or narrowly oblong, and stand apart from one another without touching. In the X. mwasumbii group, they are short and thick, and, again, not at all connivent (Johnson et al. 1999). The most conspicuous stigmas of the genus occur in X. longipetala, where the connivent stigmas reach a length of 7 mm and extend well beyond the aperture formed by the overlapping petal bases (Fig. 3E).

The ovaries contain 2–12 ovules, attached laterally in a single or an irregular double row. Kramer (1969) showed that the ovules of the single row alternate in arising from placentas on either side of the suture of the conduplicate carpel, and that they are anatropous in orientation; he further observed that the vascular supply to each carpel consists of an unbranched dorsal bundle that extends to the stigma and two ventral bundles that produce short branches approaching the ovules with the main bundles then extending to the stigma as well. Sillans (1953) described and illustrated the carpels of X. ardua Sillans [= X. gilbertii in this work] as borne on a gynophore; we found the structure described as a “gynophore” in this species to be, in fact, the staminal cone outside of and surrounding the bases of the ovaries. The torus itself is flat or slightly concave underneath the gynoecium, but is neither conspicuously elevated nor hollow.

Fruit. Fruits follow the typical Annonaceae aggregate pattern, with each carpel developing into a discrete fruitlet called a monocarp. Monocarps vary in length from 1.9 cm in X. katangensis to 16.3 cm in X. rubescens, in width, i.e. adaxial to abaxial distance, from 0.3 cm in X. aethiopica to 4.0 cm in X. paniculata, and in thickness, i.e. perpendicular to width, from 0.3 cm in X. aethiopica to 3.5 cm in X. letestui. The ripe monocarps of all species, despite being somewhat fleshy and berrylike, dehisce longitudinally along the abaxial surface to expose the seeds. Xylopia shares this morphology with members of tribe Bocageeae (Johnson and Murray 1995). Monocarp number depends on effectiveness of pollination as well as carpel number; the highest numbers recorded for African species are up to 18 in X. cupularis Mildbr., up to 22 in X. flamignii, and up to 36 in X. aethiopica. The monocarps are broadly oblong or ovoid to linear and often have slight constrictions between the seeds; in X. mwasumbii and X. tenuipetala they are laterally compressed. The outside of the fruit is usually green, red, or purple, may be glabrous or pubescent, and may have oblique wrinkles and small warts when dry; in a few species, such as X. hypolampra, X. letestui, and X. phloiodora, the exocarp is strongly marked with lenticels and is brown (Fig. 4G), and in X. hypolampra and X. longipetala the fruit frequently has longitudinal ridges or ribs. The mesocarp is fibrous and green to brown, and the endocarp is usually pink to scarlet (Fig. 4A, B, D, E, G, H). In Xylopia quintasii, and in X. gracilipes, X. shirensis, X. torrei Exell, and, perhaps, other species of the Xylopia odoratissima group, the endocarp is green (Fig. 4C, F). The apex of each monocarp is obtuse to rounded or sometimes is formed into a short (1–6 mm) beak, and the monocarp base is contracted into a stipe of varying length or rarely (e.g. X. keniensis, X. paniculata, X. villosa) the monocarps are sessile on the torus.

Seeds. Monocarps contain seeds in one or two rows. The seeds are attached laterally and are parallel, at an oblique angle, or perpendicular to the long axis of the monocarp. Seed number per monocarp in African species varies from one to 20. The seeds are ellipsoid and vary in length from 5 mm in X. aethiopica to nearly 22 mm in X. paniculata. Seeds are rounded or pointed at the chalazal end and usually truncate at the micropylar end with a distinct micropylar scar. In a few species, for example, X. arenaria, X. collina, X. longipetala, and X. tomentosa, the seed suddenly narrows toward the micropylar end to form a “neck” so that the seed is pyriform. The seed coat is smooth or rarely slightly wrinkled or pitted. In all Annonaceae, the raphe/antiraphe forms a hoop that encircles the seed (Corner 1949, the “perichalazal ring” of Pirie and Doyle 2012). In Xylopia ,it may be raised into a keel, as in X. staudtii, or be flush with the surface of the seed and visible only as a faint line. The seed coat, which has only been studied in three Neotropical species, consists primarily of the outer integument, a morphology found in a number of other genera of Annonaceae (Christmann 1986). The endosperm has the ruminate pattern that is a diagnostic feature of the family, the ruminations formed by ingrowths of the inner integument perpendicular to the long axis of the seed. Lamelliform ruminations in quadrants, typical of many Annonaceae (van Setten and Koek-Noorman 1992), were present in dissected seeds of X. staudtii (sect. Neoxylopia), and X. holtzii and X. phloiodora (sect. Stenoxylopia), but in Xylopia quintasii (sect. Ancistropetala), the ruminations were peglike, irregular, and somewhat branched. Rumination pattern has not been examined for most African species, but might, if better known, prove useful for interpreting the family’s fossil record (see Pirie and Doyle 2012).

Arils of four types, arising near the micropyle, are found in African Xylopia species (Fig. 4A–D, reviewed in Stull et al. 2017). In sect. Neoxylopia, arils are yellow to red, their brushlike appearance being due to the many tightly packed fleshy rod-shaped appendages attached to a disklike base (Fig. 4A). In sect. Ancistropetala, arils consist of a ring of orange to red strips forming a reflexed fringe that completely encloses the seed (Fig. 4C). In sect. Xylopia, the aril is orange or white, fleshy, and bilobed (Fig. 4B). Finally, in X. mwasumbii and X. tenuipetala of sect. Verdcourtia, the aril forms a fleshy white cup around the end of the seed (Fig. 4D). In the African species of sect. Stenoxylopia, an aril is absent.

In species lacking an aril, a fleshy pigmented outer seed coat layer, or sarcotesta, is present. The sarcotesta is only a few cell layers thick and is not conspicuous in dried specimens. However, seeds with a sarcotesta usually dry dull brown, while those lacking a sarcotesta are shiny dark brown to black. In vivo, the sarcotesta in the Xylopia odoratissima group is orange or red (Fig. 4E, F). In the X. acutiflora group, however, the colors range from white to pale gray, light green, or verdigris (Fig. 4G, H), with the exception of reports of an orange sarcotesta in X. phloiodora.

Figure 4. 

Fruits and seeds of representative Xylopia species. A Xylopia staudtii from Democratic Republic of the Congo B Xylopia aethiopica from Republic of the Congo C Xylopia quintasii from Cameroon D Xylopia tenuipetala from Mozambique E Xylopia collina from Mozambique F Xylopia gracilipes from Mozambique G Xylopia hypolampra from Gabon H Xylopia tanganyikensis from Tanzania. A by Quentin Luke B by David Harris C, G by Thomas L. P. Couvreur D by Jonathan Timberlake E, F by Mervyn Lötter H by Noriko Itoh. C reproduced with permission of Thomas L. P. Couvreur and of the American Society of Plant Taxonomists D reproduced with the permission of Jonathan Timberlake and of the Board of Trustees, Royal Botanic Gardens Kew.

Floral biology and seed dispersal

Floral biology. At anthesis, Xylopia flowers produce a pollination chamber surrounding the androecium and gynoecium. It is formed by the petals and reinforced by the calyx. Flowers are protogynous, with varying degrees of temporal separation between stigmatic receptivity and anther dehiscence. What we know of floral biology in the genus is in accordance with a small beetle pollination system, considered ancestral for the Annonaceae (Saunders 2012).

Petal orientation at anthesis varies among species within the genus, with corresponding differences in the size and shape of the floral chamber. Flower colors, which range from white to red, and fragrances are the likely attractants for pollinators. The fragrance of Xylopia flowers is often noted by collectors, but seldom with qualitative descriptors. Of descriptors provided, some are positive, for example the fragrance of X. odoratissima was compared by one collector to that of a sweet pea (Jenkins 1) and X. aurantiiodora was named for the resemblance of its floral fragrance to that of Citrus flowers. On the other hand, the scent of Xylopia arenaria flowers is described variously as the smell of over-ripe bananas to the “smell of Annonaceae with overlying smell of cats” (Mabberley and Harris 1516). There is, thus, enough variation in attractants to expect variation in flower visitors.

Little is known of pollinator rewards provided by Xylopia flowers. Even small flowers probably provide enough pollen to serve as a food reward. The differentiated margins of the inner petal base, seen in the species of sect. Ancistropetala and in X. flamignii, X. gilbertii, and X. toussaintii of sect. Stenoxylopia, may serve as food tissue, or are perhaps secretory in nature, but no evidence of feeding damage to these tissues was observed. Likewise, most species have both inner and outer staminodes that could have nutritional value. While the inner staminodes usually adhere tightly to the bases of the stigmas, and may have a protective function, the outer staminodes are readily accessible to visitors inside the pollination chamber. The floral chamber may provide a mating place for visitors, and, in some species, the chamber may also provide thermogenesis (Saunders 2012.)

We briefly observed the floral biology of Xylopia arenaria, sect. Stenoxylopia, in eastern Tanzania in April, 1996. A total of 27 flowers in or approaching anthesis were marked on two individual trees and followed over 3–4 visits during a 21-hour period. Flowers were inspected in the late afternoon of 26 April and then again in early morning and early and late afternoon on 27 April. We recorded the petal color, petal position, stigmatic receptivity via exudate production (Ratnayake et al. 2007), anther dehiscence, and the presence of visitors for each flower.

By comparing the stages of anthesis present at each observation time, we reconstructed the sequence of floral events. In X. arenaria, stigmatic receptivity was signaled by outward movement of the narrow apices of the inner petals, beginning in the late afternoon or evening of Day 1 (Fig. 3H).

By the morning of Day 2, the inner petal apices were bent nearly perpendicular to the outer petals, which remained erect. Color darkened from cream to yellow or from yellow to pale orange. The stigmas were white, pressed tightly together, and shining with stigmatic exudate. An unpleasant rotting fruit scent was very strong. This stage continued until the following morning.

On the morning of Day 3, the flowers were still in the pistillate stage, but the scent was weaker. By early afternoon, the stigmas had begun to separate and turn dark, which we interpreted as signaling the end of the pistillate stage. By early afternoon, the stigmas were beginning to abscise and the stamens to loosen. Scent was less strong during the staminate stage, and petal position did not change. During the night of Day 3, the petals and stamens dropped so that by morning only pedicel, sepals, and carpels remained. Most pedicels dropped soon after.

Four floral visitors were observed. A weevil was present in one flower from early morning until early afternoon during the pistillate stage. Staphylinid beetles were observed in three separate flowers, two in pistillate-stage flowers in early morning and one in a staminate-stage flower in late afternoon.

In a detailed study of a second species of section Stenoxylopia, Xylopia championii from Sri Lanka, Ratnayake et al. (2007) marked ten flowers on five individual trees to follow the stages of anthesis, and found that the flower buds grew over a period of one month, with the petals of both whorls gradually bending apart at the end of that time. Stigmatic receptivity lasted for 15–17 hours, and was signaled externally by the partial closing of the outer petals and the tight closing of the inner petals to form a pollination chamber. The petals forming the chamber then reopened and a 6-hour non-receptive interim stage commenced. This was followed by anther dehiscence lasting for ca. 17 hours. Overall petal color changed from greenish yellow to light yellow before the onset of stigmatic receptivity, and the stamens and adaxial base of the inner petals gradually darkened from pink to dark red or purple by the onset of anther dehiscence. Small weevils carried pollen and visited the flowers during the pistillate and staminate stages, but were not present before anthesis or during the interim stage. While limited self-compatibility was demonstrated, the breeding system is clearly directed toward xenogamy (see also Pang and Saunders 2014).

In contrast with X. championii, the petals of X. arenaria did not open and close during anthesis but rather maintained the same orientation throughout all stages. The pollination chamber was composed of the outer petals and only the bases of the inner petals, rather than of the entire inner petals. The period of stigmatic receptivity was longer, about 36 hours, but the period of anther dehiscence was much shorter (6–8 hours). There was no distinct interim stage between stigmatic receptivity and anther dehiscence in X. arenaria. Xylopia arenaria observations thus point to a system in which visitors are likely to remain in the flowers throughout anthesis. As with X. championii, floral synchrony within individuals (Murray and Johnson 1987) was not observed. Xylopia arenaria produces hundreds of flowers that form few fruits, a possible indicator of a breeding system that promotes outcrossing, as Ratnayake et al. (2007) found in X. championii. In contrast, collections of X. aethiopica, X. longipetala, and X. thomsonii frequently have many fruits with many monocarps per fruit, suggesting inbreeding mechanisms may be present in these species (see Pang and Saunders 2014 for an overview of floral biology in the family).

These comparisons suggest the limitations of generalizing from a few examples of floral biology. Five of the six sections of Xylopia are represented in Africa and these include the basal clades of the genus. Other studies of Xylopia species, reviewed by Saunders (2012), all belong to section Xylopia, represented by only a single species in Africa. Species in this section all have a well-developed staminal cone and flat-topped anther connective apices typical of Annonaceae, characteristics that have been suggested to protect against feeding by floral visitors (Ratnayake et al. 2007). However, neither of these characteristics is present, for example, in the Ancistropetala section of the genus endemic to Africa. Given the range of variation in floral morphology and the events of anthesis, selection on floral biology traits appears to have been important in evolution within the genus but is still poorly known.

Seed dispersal. Ripe Xylopia fruits hang downward on a short woody pedicel with the abaxial surface of the separate monocarps facing outward. Depending on the species, there may be up to 36 monocarps per fruit. The monocarps dehisce asynchronously, opening longitudinally to display the seeds (Fig. 4). A single monocarp may hold up to 20 seeds varying in length from 5 to 22 mm. An aril or sarcotesta provides a food reward for dispersers. The striking color contrasts between the fruit and seeds are achieved by a variety of morphologies, but all combinations are in accord with a recognized syndrome of dispersal by diurnal vertebrates with trichromatic color vision. This syndrome encompasses the two main groups of Xylopia seed dispersers documented for Africa, birds and primates (Gautier-Hion et al. 1985, Lahm 1986, Whitney et al. 1998, Holbrook and Smith 2000, Clark and Poulsen 2001, Poulsen et al. 2001, Eckardt and Zuberbühler 2004, Lamperti 2004, Koné et al. 2008, Lamperti et al. 2014).

A study of hornbills in the Dja Reserve in southeastern Cameroon documented bird dispersal for 56 plant species, including four species of Xylopia (Whitney et al. 1998). The canopy species X. hypolampra, X. letestui, X. rubescens, and X. staudtii were fed upon by up to three species of large hornbills, Ceratogymna atrata, C. cylindricus, and C. fistulator. The birds effectively dispersed seeds away from the parent trees. Defecated seeds of three of the four species germinated, and, in the case of X. rubescens, seed germination was greater after gut passage compared to controls. Holbrook and Smith (2000) calculated the seed shadow produced by two hornbill species for several canopy trees, including X. hypolampra, and found that in X. hypolampra the seed shadow extended to more than 6500 m from the parent tree, with a peak at 1000 m.

Poulsen et al. (2001), in a study of seed dispersal by a primate community, also in the Dja Reserve, reported that seeds of five Xylopia species, X. aethiopica, X. quintasii, X. parviflora, X. rubescens, and X. staudtii, were consumed by monkeys including gray-cheeked mangabeys (Lophocebus albigena), white-nosed guenons (Cercopithecus nictitans nictitans), and crowned guenons (C. mona pogonias). Seeds of X. rubescens and X. staudtii were recovered from fecal samples of gray-cheeked mangabeys, and showed about 40% and 10% germination, respectively, demonstrating that seeds can pass intact and viable through the monkey’s gut. The average passage time of 22 hours reported in this study allows for dispersal of the seeds to significant distances from the parent trees. Koné et al. (2008) reported a similar system of primate dispersers and Xylopia species in Taï National Park, Ivory Coast. Six different primates took the seeds from one or more of five Xylopia species, X. acutiflora, X. aethiopica, X. parviflora, X. quintasii, and X. villosa. The monkeys either swallowed the seeds or spat them out undamaged.

The species of Xylopia seeds taken by hornbills and by monkeys thus overlap but the overlap is not complete. For example, Xylopia quintasii is reported as a monkey food item in five studies (Mitani 1999, Poulsen et al. 2001, Eckardt and Zuberbühler 2004, Koné et al. 2008, Wang 2008) but not as a hornbill food item. Conversely, X. hypolampra was taken only by hornbills. The observed preferences may relate to tree architecture, phenology, or the nature of the food reward.

Clark and Poulsen (2001) analyzed the contributions of hornbills and monkeys to seed dispersal of canopy tree species and concluded that monkeys feed lower in the trees and feed on more species, while hornbills feed higher in the canopy and disperse greater numbers of seeds. This may explain some feeding preferences: X. hypolampra ,for example, is a slender high canopy species with a small exposed crown and therefore perhaps undesirable to monkeys. Furthermore, no smaller-stature Xylopia species were reported in the hornbill studies, while monkeys have been reported to feed on two understory species, X. acutiflora and X. parviflora (=X. longipetala).

Phenology determines the seasonal availability of fruits and seeds to dispersers as well as competition for disperser services. In Xylopia, fruiting seasons are long, and asynchronous dehiscence of the individual monocarps promotes multiple visits by dispersers to each fruit. Fourrier (2013) described fruiting patterns for three Xylopia species in the Lopé Reserve of Gabon over a ten-year period. The mean fruiting dates for the Xylopia species all fell sometime during August, but each species exhibited a different pattern. X. quintasii (probably actually X. congolensis, K. Abernethy, personal communication) had an availability duration of 4.1 months, X. aethiopica 5.3 months, and X. hypolampra 11.5 months. Thus Xylopia alone may provide a nearly year-round food source for local forest dispersers and appears to be solely dependent on these dispersers, rather than on a wider mix that includes migratory species.

The nature of the food reward presents additional variables that influence dispersers. As noted above, attractants provided by Xylopia fruits include the color contrasts of endocarp and seeds that provide a search image for dispersers. The diverse morphologies by which Xylopia species achieve these contrasts suggest intense selection. For example, arils are present in the two earlier-diverging clades of the genus (Stull et al. 2017) and could be energetically more costly for the plant than the sarcotestas that predominate in more recently diverging clades.

Alternatively, there may be differences in effectiveness of dispersal. Lambert (1999) showed that method of seed handling by primates influences dispersal. Primates may either spit or swallow Xylopia seeds. Spitting led to more limited dispersal than swallowing. Koné et al. (2008) found that arillate Xylopia seeds were both swallowed and probably spat by multiple monkey species, while seeds with sarcotestas were spat for two species but those of a third were always swallowed. These behaviors may be influenced by ease of detachment of the food reward. Arils are attached only at the base of the seed, a morphology that may promote easier removal in comparison to sarcotestas, which are formed by the outermost cell layers of the seed coat and thus adhere tightly to the entire seed.

Hornbills swallow seeds with both arils and sarcotestas whole. Surprisingly, seeds of all Xylopia species, even the large seeds of X. letestui and X. staudtii, were reported by Whitney et al. (1998) to be defecated by the hornbills rather than regurgitated from the gizzard. Seed diameter of African Xylopia species ranges from 3.2 mm to 17.3 mm, but seeds of the species fed upon by the hornbills in the Whitney et al. (1998) study trended strongly toward the larger end of this range: three of the four species had seed diameters that can exceed 10 mm. From these data, it appears that hornbills preferentially select seeds with larger rewards.

Questions remain about the nutritional qualities of the food rewards. Nutrient and mineral analysis of the aril of Xylopia staudtii by Sourd and Gautier-Hion (1986) showed that it had the highest fatty acid content and the third highest protein content as a percentage of dry weight of the 23 species of fruits and seeds analyzed. An analysis of four species of Xylopia by Lamperti et al. (2014) also indicated high fat and protein content, in addition to soluble carbohydrates and minerals. Aaron Lamperti (personal communication, July 2017) reports that the fruits and seeds were separated in this study and only the food tissues attached to the seeds were analyzed. If arils and sarcotestas provide protein and fat, these rewards could be significant sources of essential nutrients in the diet of obligate frugivores, even if not a large source of calories. Feeding preferences may also be directed by taste; for example, the arils of X. quintasii taste bitter (K. Abernethy, personal communication) but secondary chemical constituents have not been analyzed.

Xylopia seeds are eaten by several animals in addition to hornbills and monkeys. Gautier-Hion et al. (1985) suggested that seed predators such as squirrels and other small rodents may sometimes act as dispersers for Xylopia. Seeds of X. aethiopica were recovered from dung of the nocturnal genet cat (Genetta sp.) collected in the Shimba Hills of Kenya (T. Engel, personal communication); surprisingly, the aril was still intact. Smaller-seeded Xylopia species are likely to have a distinct suite of dispersers from those described here, as are the diverse orange-sarcotesta species from eastern and southern Africa.

At a community level, it is clear that multiple species of Xylopia interact with multiple dispersers. Chapman and Onderdonk (1998) argued for a co-dependency between primates and the plants on which they feed; in Congolian forests this certainly seems to be the case for Xylopia, not only with monkeys but with hornbills as well. Over 30 species of Xylopia occur in Congolian forests, all presenting a similar dispersal syndrome and perhaps reinforcing and sustaining these mutualisms. Conservation efforts must account for these co-dependencies.

Ethnobiology

There are many reports of local use of Xylopia wood as a material for building and for tools (e.g. Tessmann 1913, Focho et al. 2010). Two species, X. hypolampra and X. quintasii, are used commercially for timber: the International Tropical Timber Organisation (ITTO, http://www.itto.int/) uses the trade names “ekui” for the former and “elo” for the latter.

Bark, roots, leaves, fruits, and seeds of Xylopia have all been used in medicines throughout western and central Africa. There have also been a few reports of use in perfumes and insecticides. The plants have been prepared in myriad ways for both external and internal use (Reviewed by Burkill 1985, Prelude Medicinal Plants Database: http://www.africamuseum.be/collections/external/prelude/view_plant?pi=13170. [accessed 01.08.2017]). Various species, most frequently X. aethiopica, have been used to treat a wide variety of maladies. We found no consistent pattern of efficacy either by malady or by locality, (e.g. Agbovie et al. 2002, Focho et al. 2010, Malan et al. 2015.) When taken together, however, the record of local uses provides strong evidence that extracts of each of the plant parts have significant bioactivity; this has been borne out by phytochemical analysis. Information on individual species is recorded in the taxonomic treatment.

Knowledge of Xylopia aethiopica as a medicinal plant travelled out of Africa at an early time. The first record is possibly found in the Persian polymath Avicenna’s (Ibn Sina, 980–1037) work, the Canon of Medicine. We saw a Latin translation of this work, published in 1544, where, in Cap. 304, Avicenna describes the properties of seeds called “grano azelem” and claims that they “increase the sperm.” He compares the seeds to black pepper, points out their aromatic qualities and strong taste, and records that the plant comes from “Sceherazura.” The next reference to the plants comes several hundred years after Avicenna’s lifetime, from the Book of Simple Medicaments by the physician Serapion the Younger, later translated from the Arabic and published in Europe in various editions. Serapion (1531) refers to the hab zelim, or granum zelim, giving a brief description of the seed and its properties. In Italy, Matthioli (1565) described and illustrated Piper AEthiopicum, cited Serapion’s work, and noted that the fruits came through Alexandria in Egypt. Through the mid-eighteenth century, there are regular European references to the plants in herbals, but adding little new information. In the early 19th Century, the plant was increasingly less known in Europe (Dunal 1817) but probably still available (Brown 1818).

The boundaries between food plants and medicinal plants is often only a matter of degree (Johns 1990) and, in contrast to the wide variation in medicinal uses, the use of the fruits and seeds of X. aethiopica as a drink and as a flavoring for savory foods is widespread and consistent across much of West and Central Africa. The fruits are widely available in local markets (e.g. Van Andel 2014, Maame Dontoh, personal communication). In modern times, from a base in Senegal, a coffee drink flavored with X. aethiopica called Café Touba has become widely popular. We have seen two commercially packaged brands in the U.S.; once again X. aethiopica is available far outside the wet forests where the plants grow.

Café Touba began as a ceremonial and special occasion drink of the Mourides, a Muslim brotherhood of Senegal whose founder, Sheikh Ahmadou Bemba, is said to have brought it from Gabon. There are of course many ways to prepare the drink, but the recipe given by Mbaye Niasse, in an interview by the BBC in Dakar, called for 5 liters of water, a kilo of coffee, and half a kilo of ground Guinea pepper (Xylopia aethiopica). This mixture is then cooked for many hours (http://www.bbc.com/afrique/mobile/region/2012/08/120814_touba_senegal.shtml BBC 14 August 2012). Sugar to taste and sometimes cloves are added.

The fruits of Xylopia aethiopica are processed by drying and may be smoked. Although there is no evidence of domesticated varieties, herbarium labels indicate that the plants are occasionally cultivated. Fruits can no doubt also be easily gathered from the wild. The plants grow quickly, are relatively common in African wet forests, and are often a second growth species. Occasionally, the plants have even been described as weeds (Savill and Fox 1967). The species has a limited distribution in Senegal and, for commercial production, fruits are said to be imported from Ivory Coast or from Gabon (http://cafetouba.coffee). While the fruits of all species of Xylopia we have encountered are strongly aromatic, species other than X. aethiopica seem to be of only incidental use (see Burkill 1985). There are, however, two reports on herbarium labels of cultivated X. elliotiii from the area of Bayangam, Cameroon.

Species of Xylopia contain a wide array of bioactive and fragrance compounds. Alkaloids, tannins, and saponosides were obtained by Yemoa et al. (2008) from the fruits of X. aethiopica. Types of constituents present vary from one organ to another on the same plant: Aguoru et al. (2016) qualitatively screened the petioles, seeds, leaves, bark, and roots of X. aethiopica for nine different types of molecules and found different chemical profiles in each plant part. Alkaloids, saponins, and flavonoids were present in all parts except the roots. Other types of biologically active molecules, which included anthraquinones, glycosides, and reducing sugars, were more limited in distribution. All species that have been tested contain pungently aromatic essential oils comprising a variety of terpenes. Terpenes have been extracted from bark (Yapi et al. 2012), leaves (Konan et al. 2009, Aguoru et al. 2016), fruits (Noudjou et al. 2007, Yemoa et al. 2008, Konan et al. 2009, Bakarnga-Via et al. 2014), and seeds (Aguoru et al. 2016). Konan et al. (2009) found the overall yield of essential oils extracted from X. aethiopica leaves to be 0.25% and from fruits 1.9%. Xylopia aethiopica forms over 20% of the diet of red colobus monkeys in Korup National Park, Cameroon (Usongo and Amubode 2001) perhaps suggesting that terpenes provide stronger protection against herbivory in the fruits than in the leaves.

Among these secondary compounds, terpenes and alkaloids have been studied in the most detail. Terpene-containing oils from the fruits of X. aethiopica have shown anti-microbial activity against both Gram-positive and Gram-negative bacteria as well as fungi (e.g., Tatsadjieu et al. 2003, Fleischer et al. 2008, Hassan et al. 2014). Terpenes isolated from the fruits of X. aethiopica and X. parviflora [= X. longipetala] showed cytotoxicity against cancer cells (e.g., Konan et al. 2009, Bakarnga-Via et al. 2014). A wide variety of alkaloids have been isolated from Xylopia species, including the African species X. aethiopica and X. longipetala (listed as “X. parviflora”), and are reviewed by Lúcio et al. (2015). Anti-fungal properties may be attributable to oxoaporphine alkaloids, which were isolated from the leaves, twigs, and bark of Xylopia aethiopica (Harrigan et al. 1994).

Distribution, habitats, and conservation

The distribution of Xylopia in Africa extends from Senegal across the southern edge of the Sahel east to southern Sudan, and then south to southern Angola, northeastern South Africa, and southern Mozambique (Fig. 5). The majority of African Xylopia species occupy lowland tropical wet forest below 1000 m, a typical habitat for Annonaceae worldwide. The greatest concentration of Xylopia species occurs in the high rainfall countries of Cameroon and Gabon: together, the two countries contain 27 of the 45 African species. Habitat specializations include riparian species such as X. longipetala, X. rubescens, and X. aurantiiodora, and the montane species X. africana and X. monticola, which are only found between 650 and 2000 m. A number of species grow in seasonally dry woodlands, especially in southern and eastern Africa, an area of high endemism (Fig. 6) for the genus. Two species, X. rubescens and X. aethiopica, have large ranges that are nearly co-extensive with the African distribution of the entire genus. Xylopia rubescens appears to be an opportunistic wetland species. The distribution of Xylopia aethiopica, a secondary forest species used as a spice and medicinal plant, has likely been augmented by human activity.

Figure 5. 

Xylopia species richness in Africa, plotted by 1° × 1° Lat × Long grid cell. Bolder lines represent country borders, fainter lines lakes and major rivers.

Xylopia occurs on islands in the Gulf of Guinea, which have a generally depauperate Annonaceae flora (Figueiredo et al. 2011, Velayos et al. 2013). Closest to the mainland, the island of Bioko has three or possibly four species (Velayos et al. 2013), Principe, the smallest island, has one species, and São Tomé has three species (Figueiredo et al. 2011). No species is endemic; only the widespread Xylopia aethiopica occurs on all three islands. Other species include Xylopia africana, X. quintasii, and X. rubescens. Monkey and hornbill species known to disperse Xylopia seeds are present only on Bioko.

We mapped species richness of the genus to a 1 degree (i.e. ~ 100 km²) grid and found up to 11 species per cell (Fig. 5). The area with the greatest concentration of high-diversity cells runs in a band from southwestern Cameroon to western Democratic Republic of the Congo. The two cells, with the highest Xylopia species richness on the continent, fall within this wet forest area, one in southern Cameroon and the other including the Cabinda Province of Angola and parts of adjacent Republic of the Congo and Democratic Republic of the Congo. Both cells contain six of the same widely distributed species, but otherwise vary. Some single grid cell “hotspots” for high diversity, such as the Yangambi region of north-central Democratic Republic of Congo, are known to represent areas of intensive collecting, a bias observed previously by Sosef et al. (2017). Overall, the striking pattern of high species richness in Xylopia corresponds well to the western portion of the “Wet Central Africa” floristic cluster generated by Fayolle et al. (2014), which falls within the Congolian Biogeographic Subregion, as defined by Linder et al. (2012) and shown in Fig. 6.

Xylopia occurs in all seven of the sub-Saharan African biogeographic Regions defined by Linder et al. (2012) (Fig. 6). The areas with highest numbers of species are the wet forest Congolian Region, which includes the Guinean, Congo, and Shaba Subregions on the map, with 32 species, the southern dry forest Zambezian Region with 16 species, and the northern dry forest Sudanian Region with ten. Nearly 47% of African Xylopia species are restricted to the Congolian Region and 22% to the Zambezian Region, illustrating the high Xylopia species turnover between these two Regions. No other Region has endemic species of Xylopia, but the distributions of X. elliotii and X. nilotica are centered in the Sudanian Region.

In the Guinean Subregion (Fig. 6), the lowland wet forest is discontinuous for a short distance between southern Togo and southwestern Nigeria. This dry forest area, sometimes termed the Dahomey Gap, was proposed by White (1979, 1983) as a biogeographic boundary between western and eastern lowland wet forest species, but this boundary has not been maintained in recent biogeographic analyses (Fayolle et al. 2014, Linder 2014). Some Xylopia distributions in West Africa, however, do correspond to this boundary: three narrowly distributed species, X. acutiflora, X. dinklagei, and X. piratae, all segregates of the former X. acutiflora s. l., have distributions ending to the west of the dry forest area, while three species, X. calva, X. cupularis, and X. thomsonii, have distributions ending in south-central Nigeria east of the dry forest area. In contrast, Xylopia villosa occurs on both sides of the dry forest area, along with six more widespread lowland wet forest Xylopia species.

Figure 6. 

Xylopia species endemism by biogeographic region and subregion. For each region or subregion in which Xylopia species are present, the number above the line represents the number of endemic species and the number below the line the total number of species. Adapted from Figure 2 of Linder et al. (2012); figure used with the permission of the authors and of John Wiley & Sons, Inc.

In the Zambezian Region (Fig. 6), eight species are narrow endemics found in dry coastal forests from southern Kenya to southern Mozambique. This area has been the subject of several biogeographic analyses of its flora and fauna (Lovett and Wasser 1993, Timberlake et al. 2011). While Linder’s (2014) analysis did not recognize this region as distinct, Fayolle et al. (2014) argued for the biogeographic uniqueness of this coastal biota. In short, the center of diversity, both at the species level and at the level of major clades in the genus, lies in the Congolian Region, but in Xylopia the center of endemism lies in the coastal area of the Zambezian Region.

Africa is the only continent where all major clades of Xylopia are represented (Fig. 7). Species of all sections in Africa, except the East African section Verdcourtia, occupy Linder’s Congolian Region. This lowland wet forest area forms the center of diversity for the major clades of Xylopia worldwide (Stull et al. 2017). The drylands diversification of Xylopia in southern and eastern Africa has arisen within section Verdcourtia and the X. odoratissima group of sect. Stenoxylopia. Section Stenoxylopia occupies the widest range of any section, but the two groups delimited within it show geographic structure (Fig. 8): the X. acutiflora group extends from Senegal east to South Sudan and south to central Angola and eastern Zambia, while the X. odoratissima group extends from western Gabon east to southern Sudan and the Kenyan coast and south to northern Namibia and southern Mozambique. These distinct distribution areas suggest separate radiations, but our molecular phylogenetic analysis (Stull et al. 2017) lacks adequate resolution to support that hypothesis.

Figure 7. 

Aggregate distributions of the sections of Xylopia present in Africa. Distributions are as described in this work, based on the phylogenetic analysis of Stull et al. (2017), but with the addition of sect. Verdcourtia. Bolder lines represent country borders, fainter lines lakes and major rivers.

While a number of African species of Xylopia are widespread, over half of the species on the continent have limited distributions and are potentially threatened (Table 1). Full IUCN conservation assessments have been completed for only six African Xylopia species. We therefore quantified distributions for the 24 least widely distributed species (including some of those assessed previously), following IUCN guidelines (IUCN Species Survival Commission 2012) for determining the EOO and the AOO (Table 1). Local field work is needed to evaluate the remaining conservation criteria. All 24 species were found to have AOOs below 100 km2. As might be expected, species including X. keniensis and X. tenuipetala show both a small EOO and a small AOO. However, species including X. paniculata and X. pynaertii, which occupy relatively large EOOs, also have AOOs under 100 km2. Noteworthy is the fact that eight of the species are confined to the Zambezian Region (sensu Linder et al. 2012), underscoring the fact that the East African dry forests are a center for rare Xylopia species of limited distribution.

Figure 8. 

Aggregate distributions of the Xylopia acutiflora and X. odoratissima groups of section Stenoxylopia in Africa. Bolder lines represent country borders, fainter lines lakes and major rivers.

Conservation assessment data for 28 African species of Xylopia. Threat status was taken from the IUCN Red List on 3 January 2018. Extent of Occurrence (EOO), Area of Occupancy (AOO), and number of localities based on the present study. IUCN status abbreviations are DD = Data Deficient, EN = Endangered, NT = Near Threatened, VU = Vulnerable. Footnoted references for published non-IUCN conservation assessments are † = Onana and Cheek 2011, ‡ = Johnson et al. 2017.

Species Status EOO (km2) AOO (km2) Localities
IUCN Red List
X. africana VU 14
X. arenaria VU 6454 58 8
X. collina EN 12,374 76 10
X. elliotii VU 40
X. mwasumbii EN 3702 60 6
X. talbotii VU 27,199 20 5
Preliminary Assessments
X. acutiflora DD 103,286 68 12
X. aurantiiodora VU† 23
X. calva DD 22,406 12 3
X. congolensis DD 169,980 28 4
X. dinklagei NT 4063 28 3
X. flamignii VU† 108,538 32 8
X. gilbertii VU† 249,251 52 6
X. globosa DD 83,797 20 5
X. keniensis EN‡ 4 10 2
X. letestui EN† 19
X. lukei EN‡ 2656 22 4
X. mildbraedii EN† 129,258 36 9
X. monticola DD 14,393 36 5
X. paniculata DD 105,473 16 4
X. piratae DD 31,476 64 11
X. pynaertii DD 582,432 40 10
X. tanganyikensis EN‡ 527 10 3
X. tenuipetala EN‡ 250 13 3
X. torrei DD 7053 12 3
X. toussaintii DD 6766 16 4
X. unguiculata DD 15,417 20 4
X. wilwerthii DD 179,602 52 13

Taxonomic treatment

Xylopia Linnaeus, Syst. nat., ed. 10, 2: 1250 [+1378]. 1759, nom. conserv.

Xylopicrum P. Browne, Hist. Jamaic. 250–251 + t. 5, fig. 2. 1756. Xylopicron, orth. mut., Adanson, Fam. 2: 365. 1763. Type: Xylopia muricata Linnaeus, typ. conserv. (lectotype designated by Setten and Maas, Regnum Vegetabile 127: 99, 1993: Browne s. n., Herb. Linn. No. 1077.1 (LINN)).

Unona Linnaeus f., Suppl. pl. 270. Apr 1782. Bulliarda Necker, Elem. bot. 2: 321. 1790, nom. superfl., non Candolle, 1801. Type: Unona discreta Linnaeus f.

Krockeria Necker, Elem. bot. 2: 317–318. 1790. Type: Unona concolor Willdenow (lectotype, here designated).

Coelocline A. de Candolle, Mém. Soc. Phys. Genève 5: 208–209. 1832. Type: Coelocline acutiflora (Dunal) A. de Candolle.

Parartabotrys Miquel, Fl. Ned. Ind., Eerste bijv. 3: 374. 1860. Type: Parartabotrys sumatranus Miquel. Note: Name only appears as a nomen nudum in Fl. Ned. Ind., Eerste bijv. 1: 154, 1860.

Pseudanona (Baillon) Safford, J. Wash. Acad. Sci. 3: 17. 1913, as “Pseudannona.” Xylopia Section Pseudanona Baillon, Adansonia 4: 141–142. Jan. 1864. Type: Pseudanona amplexicaulis (Lamarck) Safford (lectotype, designated by Safford, J. Wash. Acad. Sci. 3: 18. 1913).

Description

Trees up to 50 m tall with a straight bole rising to a small conical to rounded crown, with narrow buttresses or, in a few species, stilt roots at the base of the trunk, or shrubs, the branches, in a few species, lianescent; bark smooth to scaly, variable in color. Indument of simple hairs. Twigs persistently pubescent to glabrate, usually sparsely lenticellate, longitudinally wrinkled; nodes in many African species with two axillary branches. Leaf with blades chartaceous to coriaceous, lanceolate, oblong, elliptic, ovate, oblanceolate, or obovate, apex rounded to acuminate, base cuneate to rounded, sometimes decurrent on petiole, midrib impressed to slightly raised adaxially, raised abaxially, secondary veins brochidodromous to weakly brochidodromous, petiole short, usually shallowly canaliculate. Inflorescences axillary, occasionally arising from the leafless portions of branches, 1–32-flowered; peduncles 1 to several per axil or absent, pedicels 1–several per peduncle, with 1–6 small caducous to persistent bracts; buds ovoid to linear, apex obtuse to acute. Flowers bisexual. Sepals 3, usually connate at the base and forming a cuplike calyx, in a few species free and imbricate at base. Petals 6, in 2 series of three, free, white, cream-colored, pale yellow, pale orange, or, in a few species, red in vivo; outer petals erect, slightly spreading, or curved outward at anthesis, ovate to linear, flattened to a concave base adaxially, flat, often with a faint ridge, abaxially; inner petals slightly shorter and narrower (much shorter in X. rubescens) than outer petals, ovate to linear, keeled on both surfaces but becoming concave at the base adaxially and flat at the base abaxially, often narrowed into a short claw; in a few species, the margins of the basal concavity are differentiated from the tissue of the rest of the petal. Stamens 40–200; fertile stamens clavate to oblong, apex of connective shieldlike, conical, globose, or rudimentary, often overhanging anther thecae, pubescent or papillate, rarely glabrous, anthers transversely septate, 4–24-locellate, filament much shorter than anther, articulated with the staminal cone; outer staminodes oblong to clavate, apex obtuse to obliquely truncate, rarely absent; inner staminodes often adhering to the bases of the stigmas, usually shorter than outer staminodes, clavate to oblong, apex rounded, rarely absent; filament bases connate into a staminal cone that partially or completely encloses the ovaries, the rim even or sometimes laciniate, or staminal cone absent. Carpels 2–50; ovaries oblong or ovoid, usually hairy, stigmas free or loosely connivent with tips spreading, linear, falciform, narrowly oblong, or clavate, smooth or studded with round tubercles in some species, often hairy at the apex. Torus flat or slightly concave. Fruit of up to 36 glabrate to pubescent dehiscent monocarps borne on a short woody pedicel and slightly expanded torus. Monocarps with green, red, or purple exterior and a green or pink to scarlet endocarp in vivo, linear, oblong, ovoid, or globose, often somewhat falcate, occasionally weakly torulose, apex rounded or with a curved beak or mucro, base contracted into a stipe or sessile, smooth, longitudinally ridged, finely wrinkled, or verrucose; pericarp leathery to woody when dried. Seeds up to 20 per monocarp, attached laterally in one or two rows, lying parallel, oblique, or perpendicular to long axis, oblong to ellipsoid, oblong, elliptic, or ovate in cross section, flattened at micropylar end, rounded at chalazal end, brown to black, smooth or rarely slightly pitted, dull or shiny, raphe/antiraphe forming a raised ridge encircling the seed or flat and not evident, micropylar scar elliptic to circular; seeds arillate, the aril attached around the micropyle, white, yellow, orange, red, pink, or violet in vivo, fleshy or papery, or aril absent; seed coat with a fleshy outer layer (sarcotesta) and hard inner layer, or sarcotesta absent.

A pantropical genus of ca. 180 species, in tropical Africa represented by 45 species. The only other African Annonaceae genus with elongate flower buds such as those commonly seen in Xylopia is Greenwayodendron Verdc., and the latter genus is sometimes mistaken for Xylopia on this basis; Greenwayodendron species, however, always have terminal inflorescences, which appear supra-axillary or leaf-opposed (Verdcourt 1969). The dehiscent monocarps set Xylopia apart from all other African Annonaceae genera except the East African Mkilua Verdc. (Verdcourt 1970) and Ophrypetalum Diels, neither of which has a brightly colored endocarp or seeds.

Patonia Wight (Wight 1838) is usually treated as a generic synonym of Xylopia (van Setten and Maas 1990, Turner 2011). In his generic description, however, Wight explicitly described and mentioned an apical ovule and seed, and a calyx that grows up to cover the maturing fruit. These are characters of Diospyros, not of Annonaceae. We suggest that Hiern was correct in adopting the name Patonia as a synonym of Diospyros and that Patonia walkeri Wight should be its type, as the lectotype designated is in conflict with the generic protologue. Patonia parvifolia, the other species placed in the genus when it was proposed, is a Xylopia, now re-named Xylopia patoniae I. M. Turner for nomenclatural reasons (Turner 2011).

Key to the African species of Xylopia

1 Seeds arillate, sarcotesta absent; nodes with either one or two axillary branches; staminal cone rudimentary or absent, if well developed then rim of cone even and carpels and monocarps more than 22 2
Seeds not arillate, but a fleshy sarcotesta present on the seed (waxy layer that scratches off); some nodes with two axillary branches; staminal cone well developed but usually with an irregular laciniate rim, carpels and monocarps never more than 22, often many fewer (sect. Stenoxylopia) 12
2 Aril white (seed unknown for X. lukei); apex of anther connective rudimentary, not overhanging anther thecae; inner petals completely glabrous (sect. Verdcourtia) 3
Aril yellow, orange, red, or purple; apex of anther connective evident, overhanging anther thecae; inner petals with some hairs on both surfaces, especially toward the apex 5
3 Larger leaf blades 8.2–11.9 cm long, 4.1–5.8 cm wide X. lukei
Larger leaf blades 4.6–8.7 cm long, 2.3–4.3 cm wide 4
4 Pedicels 2.4–3.5 mm long; leaf abruptly blunt-acuminate, the acumen 4–8 mm long, occasionally emarginate or obtuse; petals coriaceous to slightly fleshy X. mwasumbii
Pedicels 6.7–7.2 mm long; leaf gradually acuminate, the acumen 4–11 mm long; petals membranous X. tenuipetala
5 Aril bilobed, monocarps up to 36 per fruit; staminal cone well developed, completely enclosing the ovaries; leaf gradually long-acuminate, the acumen 6–20 mm long (sect. Xylopia) X. aethiopica
Aril not bilobed, monocarps up to 15 per fruit; staminal cone absent or rudimentary in the form of a ring only covering the bases of the ovaries; leaves short-acuminate (up to 6 mm long) or, if longer, then sharply cuspidate, not gradually acuminate 6
6 Arils membranous, fimbriate, covering at least half and often the entire seed; stigmas usually discrete; inner petals with differentiated fleshy margins around basal concavity; apex of anther connective conical to capitate and papillate to long-papillate, giving a bumpy rather than flat surface to the androecium (sect. Ancistropetala) 7
Arils brushlike, covering only base of seed; stigmas more or less connivent; inner petals with margins undifferentiated; apex of anther connective flat or with a slight bump in the center and often pubescent, but forming a flat surface to the androecium (sect. Neoxylopia) 9
7 Leaves narrowly elliptic, acute to obtuse at the apex; pubescence of outer petals buff-brown; inner petal with a distinct truncate tooth overhanging basal concavity; stigma subequal in length to ovary; seeds 13.5–21 mm long, pointed at the chalazal end X. aurantiiodora
Leaves oblanceolate to obovate, short-acuminate at the apex; pubescence of outer petals silvery to brownish gray; inner petal lacking tooth overhanging basal concavity; stigma distinctly shorter than ovary; seeds 10–12.5 mm long, rounded at chalazal end 8
8 Inflorescences usually 2-flowered, rarely up to 4, pedicels all arising independently from the axil, often recurved; outer petals chartaceous, up to 21 mm long; leaf flush white; leaf blades glabrous abaxially X. congolensis
Inflorescences up to 7-flowered, some pedicels attached to a common peduncle arising from the axil; pedicels straight or sinuous; outer petals more or less fleshy, up to 13 mm long; leaf flush red to purple; leaf blades usually appressed-pubescent abaxially, sometimes glabrate X. quintasii
9 Outer petals much longer than inner petals; monocarps strongly torulose, often moniliform X. rubescens
Outer and inner petals subequal in length; monocarps torulose or not, but not moniliform (fruit of X. globosa unknown) 10
10 Leaves oblong or elliptic, widest near midpoint, 15.7–23.5 cm long, 8.3–11.7 cm wide X. globosa
Leaves oblanceolate to obovate, widest distal to midpoint, 5.1–15.4 cm long, 2.0–7.9 cm wide 11
11 Sepals 2.6–3.5 mm wide; outer petals 5.8–9.6 mm long; aril usually yellow to orange in vivo; monocarps at most weakly torulose X. staudtii
Sepals 4.6–5.5 mm wide; outer petals 8.2–13.5 mm long; aril blood-red in vivo; monocarps distinctly torulose X. africana
12 Inner petals thickened and knobby on margins toward base; sarcotesta orange to red in vivo 13
Inner petals undifferentiated on the margins; sarcotesta orange to red or white to pale green in vivo 15
13 Leaves glabrous adaxially, veins forming a conspicuous reticulum on both surfaces; monocarps linear, glabrate, up to 22 per fruit X. flamignii
Leaves pubescent adaxially, veins at most only slightly raised on either surface; monocarps oblong, sparsely pubescent, up to 10 per fruit 14
14 Sepals 2.8–4.2 mm wide; outer petals lanceolate to ovate, 6.6–11 mm long, 2.4–4.4 mm wide at midpoint; leaves usually pubescent across entire surface, rarely only along midrib adaxially X. gilbertii
Sepals 1.9–2.3 mm wide; outer petals linear-lanceolate, 8.7–11.8 mm long but only 0.6–1.0 mm wide at midpoint; leaves always pubescent only along midrib adaxially X. toussaintii
15 Leaves persistently appressed-pubescent abaxially, the hairs overlapping and forming a visible indument; seeds in two rows, oblique to perpendicular to long axis of monocarp 16
Leaves pubescent to glabrate abaxially, if persistently pubescent then hairs not appressed or hairs small and not overlapping; seeds in one or two rows, usually oblique to long axis of monocarp 19
16 Leaves silvery-sericeous abaxially; monocarps sessile, brown, strongly lenticellate, glabrate X. hypolampra
Leaves with golden, gray, or brown pubescence abaxially; monocarps sessile or stipitate, green to brown, not lenticellate, pubescent or glabrate 17
17 Monocarps clearly stipitate, the stipes 7–24 mm long; leaf base cuneate to broadly cuneate, often oblique; flower pedicels 4.5–12 mm long X. cupularis
Monocarps sessile, narrowing gradually toward base; leaf base truncate, rounded, or at most broadly cuneate, symmetrical; flower pedicels 1.4–6.9 mm long 18
18 Leaf blade truncate at base, obtuse to acute at the apex, hairs appressed but not shiny abaxially; inflorescences with up to 4 flowers X. letestui
Leaf blade broadly cuneate to rounded at base, acute to acuminate at the apex, golden-sericeous abaxially; inflorescences with up to 8 flowers X. villosa
19 Inflorescences with up to 32 flowers; seeds 15.7–17.3 mm wide X. paniculata
Inflorescences with up to 10 flowers; seeds ≤ 10 mm wide 20
20 Secondary veins arcuate, diverging from the midrib at an angle of ca. 45° but continuously curving toward the apex, these and higher-order veins raised on both surfaces; rim of staminal cone even; monocarps ovoid, oblong, or broadly ellipsoid, 1.7–3.1 cm wide and thick X. phloiodora
Secondary veins diverging straight from the midrib at an angle of 50–70°, these and higher-order veins plane, rarely raised and reticulate abaxially; rim of staminal cone irregularly laciniate; monocarps narrowly oblong to linear, 0.5–1.5 cm wide and thick 21
21 Most pedicels with 3–6 bracts, these often imbricate and more or less persistent, even in fruit; pedicels 1 or rarely 2 per axil 22
Most pedicels with 2 bracts, these often separated and with the upper persistent in flower and the lower caducous, not usually present in fruit; pedicels 1–12 per axil (some inflorescences with >1 pedicel) 30
22 Twigs covered with erect hairs uniformly 1.5–2.0 mm long X. talbotii
Twigs covered with appressed hairs 0.1–0.5 mm long or with a mix of short appressed hairs and longer erect hairs up to 1.3 mm long 23
23 Hairs on twigs appressed and of uniform length, 0.1–0.5 mm long 24
Hairs on twigs a mix of short appressed hairs 0.1–0.4 mm long and longer erect hairs up to 1.3 mm long 26
24 Outer petals 2.2–4.1 mm wide at midpoint; seeds 12.5–14 mm long; leaf blades 9.5–17.5 cm long, 3.2–5.6 mm wide X. mildbraedii
Outer petals 1.0-2.0 mm wide at midpoint; seeds 9.2–12.3 mm long; leaf blades 6–13.7 cm long, 1.8–4.7 mm wide 25
25 Outer petals 10.5–13 mm long; coastal Liberia X. dinklagei
Outer petals (14.6–) 22–49 mm long; central Africa X. thomsonii
26 Shrubs scandent on low vegetation, ultimate twigs usually thickened at the base; outer petals 24.3–73 mm long, 0.9–1.5 mm wide at midpoint; coastal Ivory Coast and Ghana X. piratae
Shrubs or trees, usually upright but sometimes with lianescent branches, ultimate twigs not thickened at the base; outer petals 19.6–52 mm long, 1.0–2.5 mm wide at midpoint 27
27 Outer petals 2.2–2.5 mm wide at midpoint; beak on monocarps up to 5 mm long, narrow and curved; always treelike in habit X. unguiculata
Outer petals 1–2 mm wide at midpoint; beak on monocarps broad, blunt, and up to 4 mm long or often absent; treelike or lianescent shrub habit 28
28 Monocarps with seeds in two rows, 1.1–1.5 cm wide, not torulose, stipes 3–7 mm long; Sierra Leone, Liberia, Guinea, and Ivory Coast X. acutiflora
Monocarps with seeds in a single row, 0.6–1.2 cm wide, torulose, stipes 3–13 mm long; Nigeria eastward 29
29 Montane tree; monocarp stipes 8–13 mm long X. monticola
Lowland lianescent shrub or small tree; monocarp stipes 3–11 mm long X. thomsonii
30 Larger leaf blades 10–17.2 cm long, 3.6–6.5 cm wide; outer petals 2.8–5.5 mm wide at the midpoint, the adaxial surfaces glabrous except at the apex X. calva
Larger leaf blades 3.6–11.4 cm long, 1.2–5.6 cm wide; outer petals 0.5–2.5 mm wide at the midpoint, the adaxial surfaces mostly pubescent 31
31 Sepals reflexed at anthesis; petals membranous to chartaceous, the apices lax and crinkled when dry; stigmas 3.8–7 mm long; flower pedicels 6.2–12 mm long; monocarps often longitudinally ridged X. longipetala
Sepals erect to slightly spreading at anthesis; petals coriaceous to fleshy, the apices rigid or bent outward when dry; stigmas 1.3–4.4 mm long; flower pedicels 2.8–8.2 mm long; monocarps sometimes obliquely wrinkled but not longitudinally ridged 32
32 Adaxial surface of leaf blades uniformly pubescent to sparsely pubescent, the hairs sometimes denser along the midrib 33
Adaxial surface of leaf blades completely glabrous or with hairs confined to the midrib 39
33 Shrubs; outer petals erect, inner petals sharply bent outward at the base at anthesis; endocarp of mature monocarp pink to red 34
Small to large trees; outer and inner petals both curved outward from the base, the apices incurved at anthesis; endocarp of mature monocarp green (white, possibly immature, in X. holtzii) 35
34 Hairs on twigs erect, 1–2 mm long, flowers red, monocarps glabrous and somewhat pruinose X. collina
Hairs on twigs matted and twisted, 0.2–0.6 mm long, flowers white to cream-colored, monocarps pubescent, not pruinose X. tomentosa
35 Most leaves relatively narrow, the larger blades 6.1–11.4 cm long, 1.5–4.4 mm wide; some inflorescences usually branched, (2–) 3 or more flowers in an inflorescence; monocarps either uniformly pubescent or strongly verrucose 36
Most leaves relatively broad, the larger blades 3.3–10.2 cm long, 1.7–5.1 cm wide; inflorescences rarely branched, 1–2 (–6)-flowered, the flowers usually arising from the same axil on separate pedicels; monocarps sparsely pubescent to glabrate, smooth to minutely verrucose 37
36 Higher-order veins less prominently raised than the secondary veins, forming only a faint reticulum on the adaxial surface; larger leaf blades 7.4–11.4 cm long; monocarps obliquely wrinkled and minutely verrucose (visible with hand lens), stipe 3–3.5 mm thick at the midpoint; coastal Kenya and Tanzania X. holtzii
Higher-order veins equal in prominence to the secondary veins, forming a conspicuous raised reticulum on the adaxial surface; larger leaf blades 6.5–9.2 cm long; monocarps conspicuously verrucose but not much wrinkled, stipe 3.5–5 mm thick at the midpoint; Sudan to Uganda X. nilotica
37 Flower buds abruptly narrowed 3–4 mm above the base and then tapering to apex; outer petals usually 21–30 mm long, rarely shorter, and 3.4–3.9 mm wide at the base; monocarps strongly rugose, short-stipitate, 2.5–7 mm long, or sessile X. odoratissima
Flower buds tapering gradually to apex; outer petals at most 21 mm long, usually shorter, and 2.3–3.3 mm wide at base; monocarps obliquely finely wrinkled, distinctly stipitate, the stipe 3.5–11 mm long 38
38 Base of leaf blade broadly cuneate, occasionally cuneate or rounded; flower pedicels slender, 0.3–1 mm thick X. gracilipes
Base of leaf blades rounded, occasionally broadly cuneate, truncate, or subcordate; flower pedicels 1.2–1.5 mm thick X. shirensis
39 Pedicel of flower 8.5–21.5 mm long; leaves acuminate to caudate, the acumen 5–16 mm long, rounded at the tip; secondary veins 15–22 per side X. wilwerthii
Pedicel of flower 0.4–9.1 mm long; leaf apex rounded, emarginate, obtuse, or acute, if acuminate the acumen either sharp-pointed or less than 11 mm long; secondary veins 7–14 (–17) per side 40
40 Leaf blades glabrous or only with a few scattered hairs abaxially; inflorescences (1–) 2–12-flowered, with all pedicels usually branching from a single peduncle X. katangensis
Leaf blades with a sparse to dense but uniform covering of hairs abaxially; inflorescences 1–8-flowered, pedicels arising separately from the axils or sometimes with multiple peduncles from the same axil 41
41 Monocarps sessile, with pink to red endocarp; seeds in two rows, with orange sarcotesta; bracts on flower pedicel 2, both attached distal to midpoint of pedicel X. keniensis
Monocarps stipitate, the stipe 1.5–11 mm long, endocarp pink to red or green; seeds in one or two rows, with pale gray to green or orange sarcotesta; bracts on flower pedicel 2–4, attached at various points but at least one attached proximal to midpoint of pedicel (may be caducous but scar will be present) 42
42 Monocarps oblong to ovoid, not torulose, 2.6–5.4 cm long, 1.3–2.0 cm wide and thick 43
Monocarps narrowly oblong, sometimes slightly torulose, 1.6–5 cm long, 0.5–1.4 cm wide and thick 44
43 Upper bark red, rough, and scaly; outer petals 15.2–20.5 cm long; petiole 1–2.5 mm long X. pynaertii
Upper bark light gray, finely fissured or scaly; outer petals 28–38 mm long; petiole 2–4 mm long X. tanganyikensis
44 Some inflorescences with flowers branching from a common peduncle, (1–) 2–8-flowered; monocarps either uniformly pubescent or strongly verrucose 45
Inflorescences with the flowers arising from the same axil on separate pedicels, seldom branching from a common peduncle, 1–2-, rarely 4-flowered; monocarps with irregular patches of sparse pubescence or glabrate, smooth to minutely verrucose 47
45 Shrub or sub-shrub 0.4–4 m tall; larger leaf blades 2.5–6 cm long X. tomentosa
Tree up to 25 m tall; larger leaf blades 6.5–11.4 cm long 46
46 Higher-order veins less prominently raised than the secondary veins, forming only a faint reticulum on the adaxial surface; larger leaf blades 7.4–11.4 cm long; monocarps obliquely wrinkled and minutely verrucose (visible with hand lens), stipe 3–3.5 mm thick at the midpoint; coastal Kenya and Tanzania X. holtzii
Higher-order veins equal in prominence to the secondary veins, forming a conspicuous raised reticulum on the adaxial surface; larger leaf blades 6.5–9.2 cm long; monocarps conspicuously verrucose but not much wrinkled, stipe 3.5–5 mm thick at the midpoint; Sudan to Uganda X. nilotica
47 Twigs densely erect-hairy; seeds in two rows and perpendicular to long axis of monocarp; riparian forests from Sierra Leone to the Central African Republic X. elliotii
Twigs sparsely lax- or appressed-pubescent; seeds in a single row and oblique to long axis of monocarp; forests and open country of eastern and southern Africa 48
48 Flower buds ovoid-conic; outer petals 6.6–10.2 mm long, inner petals 4.7–7.2 mm long; endocarp pink to scarlet X. arenaria
Flower buds linear-lanceolate to linear; outer petals 9.5–30.4 mm long, inner petals 6.1–15.3 mm long; endocarp green 49
49 Pubescence of younger shoots consisting of straight, erect to appressed hairs; petals chartaceous, linear-filiform; monocarps 2.8–3.1 cm long; southern Mozambique in sandy habitats near the coast X. torrei
Pubescence of younger shoots consisting of kinked, bent, and twisted hairs; petals coriaceous, linear-subulate; monocarps 2.8–5.0 cm long; widespread species of southern Tanzania, Mozambique, eastern Zimbabwe, and northeastern South Africa X. gracilipes

Synoptic character list

Below are characters that are relatively noticeable and occur in only a small number of species. Species for which a character is unknown are not included, even when a prediction could probably be made. Not all species are included. Species are listed in alphabetical order.

Plants of scandent habit: X. dinklagei, X. piratae, X. thomsonii

Stilt roots: X. africana, X. paniculata, X. phloiodora, X. rubescens, X. staudtii

Bark scaly or peeling, orange to reddish brown: X. congolensis, X. pynaertii, X. quintasii, X. staudtii, X. villosa

Leaves abaxially shiny from appressed hairs: X. cupularis, X. hypolampra, X. villosa

Leaves lanceolate, truncate at base: X. letestui

Abaxial surface of leaves reddish brown: X. rubescens

Twigs with some or all hairs erect and 1–2 mm long: X. acutiflora, X. monticola, X. piratae, X. pynaertii, X. talbotii, X. thomsonii, X. unguiculata, X. villosa

Sepals reflexed at anthesis: X. longipetala

Outer petals ovate (no more than twice as long as wide): X. africana, X. flamignii, X. gilbertii, X. globosa, X. staudtii

Petals red to brown: X. collina, X. flamignii, X. gilbertii

Petals often greater than 5 cm long, linear: X. aethiopica, X. longipetala, X. mildbraedii, X. monticola, X. piratae, X. thomsonii

Inner petals with differentiated margins at base: X. aurantiiodora, X. congolensis, X. flamignii, X. gilbertii, X. quintasii, X. toussaintii

Outer petals spreading and inner petals erect at anthesis: X. lukei, X. mwasumbii, X. tenuipetala

Outer petals erect with inner petal apices emerging at right angles between them: X. arenaria, X. collina, X. keniensis, X. tomentosa

Anthers over 20-locellate: X. phloiodora

Staminal cone completely conceals the ovaries with only stigmas emergent: X. aethiopica, X. elliotii, X. hypolampra, X. monticola, X. odoratissima, X. phloiodora, X. wilwerthii

Stigmas discrete, not connivent: X. aurantiiodora, X. congolensis, X. lukei, X. mwasumbii, X. quintasii, X. tenuipetala

Stigmas bearing stalked glands: X. rubescens

Monocarps sessile, ovoid, and splitting into three segments: X. hypolampra, X. letestui, X. phloiodora, X. tanganyikensis, X. villosa

Endocarp of dehisced monocarp green: X. gracilipes, X. quintasii, X. shirensis, X. torrei

Aril covers basal half of seed or less: X. aethiopica, X. africana, X. mwasumbii, X. rubescens, X. staudtii, X. tenuipetala

Aril completely covers the seed: X. aurantiiodora, X. congolensis, X. quintasii

Geographic distribution of African species

Species lists for geographical areas in which Xylopia species occur. Species are listed in alphabetical order.

Senegal to Benin: X. acutiflora, X. aethiopica, X. dinklagei, X. elliotii, X. letestui, X. longipetala, X. piratae, X. quintasii, X. rubescens, X. staudtii, X. villosa (11)

Nigeria: X. aethiopica, X. africana, X. calva, X. cupularis, X. katangensis, X. letestui, X. longipetala, X. monticola, X. phloiodora, X. pynaertii, X. quintasii, X. rubescens, X. staudtii, X. talbotii, X. thomsonii, X. villosa (16)

Cameroon, Equatorial Guinea, São Tomé & Principe, Central African Republic: X. aethiopica, X. africana, X. aurantiiodora, X. calva, X. cupularis, X. elliotii, X. gilbertii, X. hypolampra, X. katangensis, X. letestui, X. longipetala, X. mildbraedii, X. monticola, X. paniculata, X. phloiodora, X. pynaertii, X. quintasii, X. rubescens, X. staudtii, X. talbotii, X. thomsonii, X. villosa (22)

Gabon and Republic of the Congo: X. aethiopica, X. congolensis, X. cupularis, X. flamignii, X. gilbertii, X. globosa, X. hypolampra, X. katangensis, X. letestui, X. longipetala, X. mildbraedii, X. paniculata, X. phloiodora, X. pynaertii, X. quintasii, X. rubescens, X. staudtii, X. thomsonii, X. toussaintii, X. unguiculata, X. wilwerthii (21)

Chad, South Sudan, Sudan, Uganda, Ethiopia: X. aethiopica, X. nilotica, X. rubescens, X. thomsonii (4)

Democratic Republic of the Congo: X. aethiopica, X. aurantiiodora, X. congolensis, X. cupularis, X. flamignii, X. gilbertii, X. hypolampra, X. katangensis, X. letestui, X. longipetala, X. phloiodora, X. pynaertii, X. quintasii, X. rubescens, X. shirensis, X. staudtii, X. thomsonii, X. tomentosa, X. toussaintii, X. wilwerthii (20)

Angola: X. aethiopica, X. aurantiiodora, X. cupularis, X. flamignii, X. hypolampra, X. longipetala, X. odoratissima, X. paniculata, X. quintasii, X. rubescens, X. staudtii, X. thomsonii, X. tomentosa, X. toussaintii, X. wilwerthii (15)

Eastern and Southern Africa: X. aethiopica, X. arenaria, X. collina, X. gracilipes, X. holtzii, X. katangensis, X. keniensis, X. lukei, X. mwasumbii, X. odoratissima, X. rubescens, X. shirensis, X. tanganyikensis, X. tenuipetala, X. tomentosa, X. torrei (16)

Xylopia Section Neoxylopia Engler & Diels, Monogr. afrik. Pflanzen-Fam. 6: 58. 1901.

Type

Xylopia africana (Bentham) Oliver (lectotype designated in Stull et al. 2017, p. 221).

Description

Nodes with branches from 2–3 axillary buds; outer petals ovate or linear, if outer petals linear then over four times as long as the inner petals; inner petals ovate, lacking differentiated fleshy basal margins; anther connectives shieldlike at apex, overhanging the anther thecae, rarely with the center formed into a conical point; staminal cone rudimentary, surrounding only the bases of the ovaries, rim laciniate; carpels 3–15, the stigmas free to connivent, marked with warts, tubercles, or glandular appendages; aril brushlike; seed coat smooth, sarcotesta absent. Four species in Tropical Africa.

Notes

The section was defined by Engler and Diels primarily on the basis of the distinctive aril. Three of the four species classified in this section are known to have such an aril. Fruits and seeds of the fourth species, X. globosa, are unknown, but the floral morphology of the species is strikingly similar to that of other species in the section, and molecular analysis (Stull et al. 2017) placed it as sister to X. staudtii. Stilt roots are another feature of species in this section: Xylopia africana, X. rubescens, and X. staudtii are regularly described as having such roots, but they have not been confirmed for X. globosa.

Xylopia africana (Bentham) Oliver, Fl. trop. Afr. 1: 30. 1868.

Fig. 9B–F, J, K

Melodorum africanum Bentham, Trans. Linn. Soc. 23: 477. 1862.

Xylopicrum africanum (Bentham) Kuntze, Revis. gen. pl. 1: 8. 1891.

Fissistigma africanum (Bentham) Merrill, Philipp. J. Sci. 15: 130. 1919. Type. CAMEROON. Southwest Region, Camer[oon] Mount., Feb 1862, G. Mann 1193 (lectotype, here designated: K! [000105591]; isolectotypes: GH—2 sheets! K! [000105592], P! [00169119], U! [0095511]).

Description

Tree up to 20 m tall, d.b.h. ca. 30 cm, stilt roots emerging from the trunk up to 2 m above base. Twigs brown, fine appressed-pubescent, the hairs 0.2–0.3 mm long; nodes occasionally with two axillary branches. Leaf with larger blades 6.3–15.4 cm long, 2.9–7.9 cm wide, subcoriaceous to coriaceous, discolorous, much paler abaxially in vivo, obovate, occasionally oblong or elliptic, apex short-acuminate to cuspidate, the acumen 2–10 mm long, base cuneate and decurrent on petiole, glabrous adaxially, fine appressed-pubescent abaxially; midrib plane to slightly impressed adaxially, raised abaxially, secondary veins weakly brochidodromous, 10–13 per side, diverging at 60–65° from the midrib, raised on both surfaces, higher-order veins forming a conspicuous reticulum that is slightly raised adaxially and strongly raised abaxially; petiole 6.4–9 mm long, semi-terete or canaliculate, appressed-pubescent to glabrate. Inflorescences axillary, 1–2-flowered, when 2-flowered the pedicels arising side by side from the axil, appressed-pubescent; pedicels 6.4–10.5 mm long, 0.7–1.6 mm thick; bracts 2, one to either side of midpoint, persistent, 1.2–3 mm long, broadly ovate to semicircular, apex obtuse to rounded, lower bract usually bifid from tearing down the center as the inflorescence enlarges; buds broadly ovoid, apex obtuse. Sepals erect or slightly spreading at anthesis, 1/10–1/5-connate, 4.5–7 mm long, 4.6–5.5 mm wide, coriaceous, ovate to triangular, apex acute, appressed-pubescent abaxially. Petals yellow to yellow-orange in vivo; outer petals more or less erect at anthesis, 8.2–9.5 mm long, 3.0–4.5 mm wide at base, 6.2–7.1 mm wide at midpoint, fleshy, ovate, apex acute to nearly rounded, concave in basal half adaxially, appressed-pubescent except for glabrous adaxial concavity; inner petals more or less erect at anthesis, 5.9–8.3 mm long, 1–2.6 mm wide at base, 3–3.9 mm wide at midpoint, chartaceous, narrowly rhombic to elliptic, apex acuminate or acute, base with undifferentiated margin, pubescent at apex, with finer pubescence extending into upper portion of concavity and base of concavity glabrous adaxially, pubescent at apex but otherwise glabrous abaxially. Stamens 100–120; fertile stamens 1.6–2.9 mm long, oblong to clavate, apex of connective 0.4–0.6 mm long, shieldlike, overhanging anther thecae, erect-pubescent, anthers 5–9-locellate, filament 0.5–1 mm long; outer staminodes 1.3–1.8 mm long, wedge-shaped to quadrate, apex obtuse to truncate; inner staminodes 2.8–3.4 mm long, clavate, apex rounded; staminal cone 1.8–2.7 mm in diameter, 0.6–0.8 mm high, concealing only the bases of the ovaries, rim laciniate. Carpels 9–15; ovaries 1.6–2.1 mm long, linear-oblong, pubescent, stigmas connivent, 3.2–4.6 mm long, linear, verrucose toward base, glabrous. Torus flat, 3.4–4 mm in diameter. Fruit of up to 10 glabrate monocarps borne on a pedicel 10–18 mm long, 4–5 mm thick, glabrate; torus 8–16 mm in diameter, 5–8 mm high, depressed-globose. Monocarps reddish to purplish green with red endocarp in vivo, 6.6–10.5 cm long, 1.0–1.4 cm wide, ca. 1.1 cm thick, linear-oblong to cylindrical, occasionally slightly falciform, torulose, apex mucronate, the beak 1–1.5 mm long, base contracted into a stipe 10–18 mm long, 2.5–5 mm thick, verrucose and longitudinally wrinkled; pericarp ca. 0.8 mm thick. Seeds in a single row, lying parallel to long axis of monocarp, up to 5 per monocarp, 13–15 mm long, 9–10.5 mm wide, 8.5–9 mm thick, ellipsoid, broadly elliptic in cross-section, truncate at micropylar end, rounded at chalazal end, black, smooth, shiny, raphe/antiraphe plane, micropylar scar ca. 1.5 mm in diameter, circular; sarcotesta absent; aril blood-red in vivo, dull orange-brown when dried, brushlike, 8–10 mm in diameter, ca. 4 mm high, fleshy, granular.

Figure 9. 

Xylopia globosa and X. africana. A, G–I X. globosa A Leaf G Inner petal, abaxial view, showing keel H Inflorescence, showing four buds and one flower with petals fallen I Outer petal, adaxial view B–F, J, K X. africana B Seed, lateral view with most of aril appendages fallen C Four inflorescences D Seed, micropylar end view E Inner petal, abaxial view F Outer petal, adaxial view J Leaf K Fruit. A, G–I from Normand s. n. (P), B, D, E, F, J, K from Letouzey 14551 (WAG) C from Thomas 4554 (MO).

Phenology

Specimens with flowers have been collected October–March and in May, with buds in August and November, and with fruits in September–January, March, and May.

Distribution

(Fig. 10). Occurs in montane and submontane mossy forests at elevations of 900–2000 m in southeastern Nigeria, southwestern Cameroon, and on the islands of Bioko (Equatorial Guinea) and São Tomé (São Tomé & Principe).

Local names

No local names were reported for this species on specimen labels, but Focho et al. (2010) listed the name “Hweneta (Ghana)” as applied to this species in the Mt. Cameroon area of Cameroon; the name “hwentea” is used widely in Ghana for Xylopia aethiopica.

Additional specimens examined

NIGERIA. Cross River: Obudu District, Obudu Plateau, 18 Mar 1964 (fl), Hopkins FHI 54307 (WAG); Ogoja Province, Sonkwala area of Obudu Division, grass plateau above Ikwette, 5200 ft, 28 Dec 1948 (fl, fr), Savory & Keay FHI 25179 (K); Northern Ranges, Obudu Ranch, SE State, ca. 5200’, 4 Jan 1973 (fl), Lock GC43569 (K); Boshi Extension Forest Reserve, 6°20'N, 9°20'E, alt. ca. 1600 m, 23 May 1971 (fl, fr), van Meer 1768 (WAG—2 sheets). CAMEROON. North: Chaîne de Nkohom à 42 km SSW de Ndiki, 14 Nov 1983 (buds, fr), Nkongmeneck 580 (P).—Northwest: Gazette Bali Ngemba F. R., 5°48.02'N, 10°05.78'E, 1700 m, 14 Nov 2000 (buds, fr), Cheek 10527 (K, MO); West Division, Gazette Bali Ngemba F. R., 5°49'N, 10°05'E, 1600 m, Mantum, 5 Oct 2001 (fr), Onana 1825 (K), Onana 1835 (K); Bali Ngemba F. R., 5°49.59'N, 10°05.57'E, 1700 m, 9 Nov 2000 (bud), Tadjouteu 410 (K).—Southwest: Buea, 1906 (fl, fr), Deistel 154 (A, BM, P); without definite locality, s. d. (fr), Deistel 454 (GH); Buea, 1000 m, Lehmbach 41 (B); Buea, Lehmbach 137a (B, M); Monts Rumpi-Rata Mount, 1788 m, 2 km au SW de Dikome Balua, 35 km NNW Kumba, 24 Mar 1976 (fl, fr), Letouzey 14551 (K—2 sheets, MO, P, WAG); Buea, 3000 ft., Maitland 233 (K, PRC); Cameroon Mountain, Buea area, 3–4000’, 1930 (fl, fr), Maitland s. n. (K); Mt. Cameroun, NW de Buèa, 13 Mar 1981 (st), Meijer 15378 (DSM, K, MO); southern slope of Mount Cameroon above Batoke, 4°08'N, 9°05'E, 900-2000 m, 9–20 Jan 1984 (fl), Thomas 2981 (K, MO); forest in the Rumpi Hills, near Dikome Balue, 4°53'N, 9°53'E, Mar 1984 (fl), Thomas 3305 (K, MO, P, WAG); savanna with forest galleries near Aguosho, 10 km SSW of Akwaya, 6°18'N, 9°28'E, 1200 m, 19-20 Mar 1985 (fl), Thomas 4554 (MO, P); Limbe District, Fako Division, Mt. Etinde, N face of N ridge, ca. 1220 m, 24 Oct 1992 (fl, fr), Wheatley 605 (P).—West: Route Batcha-Batschingou (22 km ESE Bafang), 23 Nov 1974 (fl, fr), Letouzey 13300 (K, MO–2 sheets, P, WAG); Region M’Bamileke [“M’Bamileleke”], 19 Dec 1957 (fr), de Wit 7947 (WAG—3 sheets). EQUATORIAL GUINEA. Bioko: entre Moca y el cruce Luba—Riaba, 1400 m, (st), Fernández Casas 11693 (K); entre Moca y Riaba por el camino viejo, 1280 m, 20 Feb 1989 (fl, fr), Fernández Casas 11823 (K); entre Moca y el lago Loreto, 1510 m, 21 Feb 1989 (fl, fr), Fernández Casas 11884 (K); Finca Puente, carretera de Usola a Moná, km 17, 20 Jan 1947 (fr), Guinea 1658 (MO); Biao Peak Trail, Pt 128-Pt 130, 3.36272°S, 8.65264°E, 1500 m, 13 Mar 2007 (fl, fr), Luke et al. 11858 (K); Bioko Sul, Balacha North Trail, 3.3797°N, 8.6669°E, 1300 m, 28 Sep 2009 (fr), Luke 13606 (MO). SAO TOME & PRINCIPE. Vila José, NW of Ribeira Peixe, track between Vila José and Cão Grande, 150–250 m, 21 Jan 1980 (fl, fr), de Wilde et al. 220 (P, WAG—2 sheets); Island of St. Thomas, rec. Nov 1861 (fr), Mann s. n. (K-000199061, K-000199062, K-000199063, P-00169118 as Mann 1193); Ins. S. Thome in sinu Biafra, ad Fazenda do Monte Coffé, 1860 (fl, yg fr in drawing), Welwitsch 764 (BM).

Xylopia africana is most similar to Xylopia staudtii. It is a smaller tree that can be distinguished by its larger sepals, obtuse outer petal apices, and red arils on the seeds. Keay (1954–1958, 1989) indicated that the leaf veins of X. africana are dark crimson on the underside of the leaves, but this has not been reported by other collectors and we did not observe this characteristic in dried specimens. The label of Cheek 10527 described the fresh leaves as “nearly white below” and the leaves of dried specimens usually have a uniform tan color abaxially. Xylopia africana also resembles X. globosa, but has smaller obovate leaves, obtuse ovate outer petals, and lacks a keel on the abaxial surface of the inner petals.

Xylopia africana occupies a unique habitat among African Xylopia species, occurring in mossy submontane to lower montane forest, reaching elevations of 2000 m. Bryophytes attached to the branches of several collections of X. africana (particularly conspicuous on the specimen Nkongmeneck 580) suggest the high humidity of the forests in which it grows. Associated species at one site in Cameroon included Carapa grandiflora, Garcinia spp., Psychotria spp., and Syzygium staudtii (Letouzey 14551). Soils in the forests in which the plants grow are acidic and sandy, with variable mineral nutrient composition (Fonge et al. 2013). Xylopia africana is a canopy tree confined to these forests and is one of many endemic plant species threatened by continued clearing of the forests for agriculture (Onana and Cheek 2011, Fonge et al. 2013). It is one of the few Xylopia species with a distribution extending to islands in the Gulf of Guinea, where it occurs on Bioko and São Tomé. On the former, it is found at elevations above 1200 m, while the collection de Wilde et al. 220 from São Tomé gives an elevation of only 150–250 m and a habitat of “old secondary forest with remnants of primary forest.”

The collection de Wit 7947 appears to be a mixed collection. Leaves in packets and some of the monocarps are X. africana, but some detached monocarps in packets have much smaller seeds oriented obliquely to the long axis of the monocarp and may be those of X. thomsonii, which was collected by de Wit as de Wit Herb. 7952 (WAG).

Bentham gave the type information as from “Island of S. Thomas off the West Coast, and Cameroon Mountain, at 4000 feet (G. Mann).” The specimen Mann 1193 at K (ex Herb. Hook., K-000105591) from the “Cameroon Mountain 4000 ft” locality, collected in Feb. 1862, has a flower and relatively small leaves, as well as sketches, presumably by Bentham, of stamens, carpels, and petals mounted on the sheet. This specimen is chosen as the lectotype. A second sheet at K (K-000105592), stamped Herb. Hook., is also numbered Mann 1193 from the same location and date, has flowers and relatively small leaves and is considered an isolectotype. The other sheets at Kew collected by Mann (K-000199061, K-000199062, and K-000199063) all labeled as having come from “St. Thomas,” have no collection number, have leaves that are larger than those of the lectotype specimens, and have fruits.

There are two sheets at P. A sheet numbered 1193 and labeled Cameroon Mt, Mann, 1862, has fruits and larger leaves. A second sheet has a specimen with flowers and smaller leaves and a printed ticket giving the S. Thomas locality but no collection number. The two labels seem to have become reversed in the distribution of the duplicates. We consider the lectotype material to be the specimens with smaller leaves and flowers whatever collection number or locality may be indicated on the sheet, as they all seem to represent the same gathering.

Xylopia globosa D. M. Johnson & N. A. Murray, sp. nov.

Figs 3A, 9A, G–I

Diagnosis

Species resembling Xylopia africana in its short broad flowers with outer petals thicker and broader than the inner petals, but differing in the glabrous twigs and leaves, the leaf blades consistently larger (15.7–23.5 cm long, 8.3–11.7 cm wide), the smaller and wider sepals, the more rounded apices of the outer petals, and the conspicuously keeled inner petals.

Type: GABON. Ogooué-Lolo, Chantier Bambidie (CEB), ca. 70 km E of Lastoursville, 57 km on CEB road to Okondja, 0°46.6'S, 13°23.6'E, 325 m, 1 Nov 2005, M. S. M. Sosef et al. 2180 (holotype: WAG! [1540447]; isotypes: OWU—2 sheets! WAG! [1540446, 1540448, 1540449]).

Description

Small tree or shrub up to 8 m tall, d.b.h. up to 25 cm, bole cylindrical, knee roots [ex Sosef et al. 2180] on lower 0.5 m of trunk; bark light gray, smooth. Twigs light brown to gray-brown, eventually reddish brown, glabrous or with a few weak hairs ca. 0.4 mm long and then soon glabrate; nodes with axillary branches not seen. Leaf with larger blades 15.7–23.5 cm long, 8.3–11.7 cm wide, subcoriaceous, paler or discolorous abaxially, oblong to oblong-elliptic or oblong-oblanceolate, apex cuspidate, the cusp 3.5–9 mm long, or rarely emarginate, base rounded to broadly cuneate and decurrent on petiole, glabrous on both surfaces; midrib slightly impressed adaxially, raised abaxially, secondary veins weakly brochidodromous, 10–14 per side, diverging at 65–75° from the midrib, slightly raised on both surfaces, higher-order veins indistinct or slightly raised adaxially, plane to slightly raised abaxially, usually forming a conspicuous reticulum on both surfaces; petiole 9–26 mm long, canaliculate adaxially, glabrous. Inflorescences axillary, 1–2-flowered, finely appressed-pubescent; peduncle 1 per axil, 3.5–5.2 mm long; pedicels 1–2 per peduncle, 6.7–10.5 mm long, 2.6-2.9 mm thick; bracts 3, evenly spaced on pedicel, persistent, 2.4–4 mm long, broadly ovate to semicircular, apex rounded; buds depressed-globose, apex rounded. Sepals spreading at anthesis, 1/3–1/2-connate, 4.8–6 mm long, 7–10 mm wide, coriaceous, crescent-shaped to nearly semicircular, apex rounded or obtuse, sparsely pubescent to glabrate abaxially. Petals yellow in vivo; outer petals slightly spreading at anthesis, 9–13.4 mm long, 10–10.5 mm wide at base, 8.7–9.3 mm wide at midpoint, fleshy, broadly ovate, apex obtuse to rounded, finely pubescent on both surfaces except for the glabrous adaxial concavity; inner petals slightly spreading at anthesis, 7.8–9.3 mm long, 1.5–1.6 mm wide at base, 3.5–4.7 mm wide at midpoint, chartaceous to coriaceous, narrowly rhombic, deeply concave, strongly keeled abaxially, apex acuminate, base with undifferentiated margin, pubescent at apex on both surfaces but otherwise glabrous and somewhat verrucose. Stamens ca. 100; fertile stamens 1.7–2.3 mm long, narrowly oblong, apex of connective 0.5–0.8 mm long, shieldlike, overhanging anther thecae, puberulent to glabrate, anthers 8–11-locellate, filament 0.3–0.4 mm long; outer staminodes 1.6–1.8 mm long, wedge-shaped to quadrate, apex truncate; inner staminodes 1.7–2.6 mm long, clavate or narrowly oblong, apex rounded; staminal cone 6–7 mm in diameter, 1.3–1.9 mm high, concealing only the bases of the ovaries, rim laciniate. Carpels ca. 15; ovaries 1.8–2.5 mm long, narrowly oblong, densely pubescent, stigmas loosely connivent, 5–5.7 mm long, linear, studded on sides with round tubercles. Torus flat, 6–7.5 mm in diameter. Fruit and seeds unknown.

Phenology

Specimens with flowers were gathered in September and November.

Distribution

(Fig. 10). Known from four scattered localities in Gabon and from one locality in the southern Republic of the Congo; secondary forest and forest edge; 80–325 m.

Local name

Ntsua (Normand s. n.).

Figure 10. 

Distributions of Xylopia africana, X. globosa, and X. staudtii. Bolder lines represent country borders, fainter lines lakes and major rivers.

Additional specimens examined

GABON. Estuaire: Cristal Mountains, 9 km S of Kinguélé, ca. 0°24'N, 10°15'E, 80 m, 21 Sep 1994 (st), Breteler et al. 12978 (WAG); Estuaire du Gabon, sud de Chinchoua [0.0149°N, 9.8094°E], 16 Sep 1959 (fl), Normand s. n. (P).—Moyen-Ogooué: about 10 km NNW of Ndjolé, 0°04'S, 10°47'E, 150 m, 25 Sep 1994 (st), Breteler et al. 13000 (MO, WAG). REPUBLIC OF THE CONGO. Environs de Dimonika, forêt vieille secondaire entre tour meteo et piste Kuilila–Makaba, 14 Dec 1982 (st), Cusset 1200 (P-01963323).

The flowers of Xylopia globosa are large, fleshy, and spherical, and scarcely resemble those of a Xylopia. In addition, the leaves of this new species are the largest of any African Xylopia, oblong to elliptic in shape, and usually sharply cuspidate at the apex, and allow confident identification of sterile specimens. The species is most similar to X. africana from which it differs in several additional floral features: the sepals are wider than long and crescent-shaped to semicircular, the outer petals are rounded at the apex, and the inner petals have a crestlike keel on the abaxial surface.

Fruits and seeds of Xylopia globosa are not yet known. A specimen from Equatorial Guinea (Litoral: Monte Alen National Park, Monte Mitra, 01°21'46"N, 9°57'40"E, 1000 m, 30 Sep 2005 (fr), Leal et al. 817 (MO)) is possibly a collection of this species with fruits. This specimen was taken from a tree 10 m tall, the fruit described as having black seeds with red arils. The plant was growing on a swampy mountain summit at 1000 m in elevation. The specimen was initially identified as X. staudtii, but its leaf blades are thinner, larger, and more rounded at the bases than is typical for that species, with a sharply short-acuminate to cuspidate apex. Xylopia staudtii typically has yellow to orange arils, and fruits on a tree 10 m in height would also be unusual. The leaves of this specimen are more similar in shape to those of X. globosa than to those of X. staudtii, but are smaller (largest 12.4 cm long, 5.8 mm wide, with a petiole 5 mm long and acumen 9 mm long) and chartaceous. There are no seeds present on the specimen, only two detached and dehisced monocarps.

Xylopia rubescens Oliver, Fl. trop. Afr. 1: 30. 1868.

Fig. 11

Xylopicrum rubescens (Oliver) Kuntze, Revis. gen. pl. 1: 8. 1891. Type. NIGERIA [“Upper Guinea”]. Rivers, Old Calabar, s. d., W. C. Thomson 53 (holotype: K! [000199073]).

Xylopia klaineana Pierre ex Engler & Diels, Monogr. afrik. Pflanzen-Fam. 6: 59–60. 1901.

Xylopia rubescens Oliver var. klaineana (Engler & Diels) Pellegrin, Bull. Soc. Bot. France, Mém. 31: 70. 1949. Type. GABON. Without definite locality, Oct 1898, T.-J. Klaine 1327 (holotype: P! [00169139]; isotypes: B! [100154150], P! [00169138]).

Xylopia humilis Engler & Diels, Monogr. afrik. Pflanzen-Fam. 6: 60 + t. 21B, a–f. 1901. Type. LIBERIA [“Oberguinea”]. Grand Bassa County, Fishtown bei Granbassa, 27 Aug 1898, M. Dinklage 2006 (lectotype, here designated: B! [10 0154147]; isotypes: A! [00061927, 00062417], B! [100154145, 100154146, 1001541480], K! [000199074, 000199075, 000199076]).

Xylopia batesii Engler & Diels, Monogr. afrik. Pflanzen-Fam. 6: 62. 1901. Type. CAMEROON or GABON. Angom, 70 engl. Meilen östlich von Gabun, Oct 1896 [29 Oct 1897 on P sheet], G. L. Bates 561 (holotype: K! [000199058]; isotypes: BM! [000510769], G! [00190711], P! [00169131, 00169132]).

Xylopia butayei De Wildeman, Ann. Mus. Congo, Sér. 4, Bot. 1: 33. 1902. Type. DEMOCRATIC REPUBLIC OF THE CONGO. Kongo Central, Malela (Bas-Congo), R. P. Butaye, coll. J. Gillet 2239 (holotype: BR!; isotype: BR! [0000008825391]).

Xylopia zenkeri Engler & Diels, Bot. Jahrb. Syst. 39: 480. 1907. Type. CAMEROON. South Province, bei Bipindi unweit Mimfia im Urwald, Mar 1904, G. A. Zenker 2827 (holotype B! [100154149]; isotypes: BM! [000511041], G! [00190712, 00190713], GOET! [005735], HBG! [502474], K! [000199060], L! [0196246], M! [0107919], P! S! [07-13458], WAG! [0065882], WU! [0025792]).

Xylopia gossweileri Exell, J. Bot. 64: Suppl. 6. 1926. Type. ANGOLA [“Portuguese Congo”]. Cabinda Province, Cabinda, Pango Munga, Mayumbe, s. d., J. Gossweiler 6222 (holotype: BM! [000511046], photos at GH, MO, NY).

Description

Tree up to 25 m tall, d.b.h. up to 70 cm, rarely described as a shrub or liana, bole straight, cylindrical, usually with stilt roots arising from the trunk up to a height of 2 m, short secondary branches forming a narrow crown; bark white, pale yellowish brown, or light gray, smooth. Twigs brown to gray, eventually whitish gray, initially appressed golden-pubescent, the hairs 0.2–0.5 mm long, but soon glabrate; nodes occasionally with two axillary branches. Leaf with larger blades 7.3–21.3 cm long, 3.6–8.4 cm wide, subcoriaceous, occasionally chartaceous, strongly discolorous, olive-green adaxially, rusty or orange-brown abaxially, rarely concolorous, oblong, elliptic, or oblanceolate, apex short-acuminate or cuspidate, the acumen or cusp 2–15 mm long, occasionally acute or rounded, base cuneate to occasionally rounded and decurrent on petiole, glabrous adaxially, finely appressed-pubescent abaxially, rarely glabrous; midrib impressed to plane adaxially, raised and usually formed into a sharp keel distal to the midpoint abaxially, secondary veins weakly brochidodromous, 8–16 per side, diverging at 45–70° from the midrib, slightly raised adaxially and abaxially, higher-order veins forming a conspicuous reticulum that is distinctly raised on both surfaces, rarely indistinct; petiole 5.4–12 mm long, canaliculate, sparsely appressed-pubescent to glabrous. Inflorescences axillary, usually from the axils of fallen leaves, 1–3 flowered, pubescent; peduncles 1 per axil, 1.5–2.5 mm long; pedicels 1–3 per peduncle, 3.5–8.5 mm long, 1–1.3 mm thick; bracts (2) 3–5, evenly spaced up to 1/2–2/3 distance from base, persistent, uppermost 1.1–2.9 mm long, ovate, apex obtuse; buds linear-subulate to linear-lanceolate, occasionally falciform, apex acute, occasionally uncinate. Sepals spreading at anthesis, nearly free to 1/3-connate, 2.2–4.2 mm long, 3.0–3.5 mm wide, coriaceous, ovate to broadly triangular, apex acute, sericeous abaxially. Petals yellow, yellow-orange, or caramel-colored, the inner petals red except for the cream to yellow base and apex in vivo; outer petals erect or slightly spreading at anthesis, 17.6–35 mm long, 2.5–5.1 mm wide at base, 1.3–3.4 mm wide at midpoint, fleshy, linear, apex acute, appressed-pubescent adaxially but with a glabrous patch at base, appressed-pubescent abaxially; inner petals erect at anthesis, 3.5–6.7 mm long, 2.2–4.6 mm wide, fleshy, rhombic to ovate, apex acuminate, the acumen 1.4–3.1 mm long, base with undifferentiated margin, pubescent on acumen and glabrous toward base adaxially, keeled and pubescent in distal half to either side of the keel abaxially. Stamens 70–77; fertile stamens 1.6–2.2 mm long, quadrate, oblong, or clavate, apex of connective 0.4–0.7 mm long, shieldlike, overhanging anther thecae, puberulent or papillate, anthers 6–8-locellate, filament 0.3–0.9 mm long; outer staminodes 1.2–2.5 mm long, oblong-pentagonal, oblong, or ovate, apex obtuse; inner staminodes 1.1–1.3 mm long, narrowly oblong, apex obtuse to truncate; staminal cone 2.1–2.4 mm in diameter, 0.3–0.8 mm high, concealing only the bases of the ovaries, rim laciniate. Carpels (4–) 7–12; ovaries 1.0–2.1 mm long, narrowly oblong, golden-tomentose, stigmas loosely connivent, 1.4–2.9 mm long, linear, bearing glandular appendages. Torus flat, 2.3–3.0 mm in diameter. Fruit of up to 15 glabrate monocarps borne on a pedicel 9–15 mm long, 2.2–7 mm thick, glabrate; torus 6–14 mm in diameter, 5–10 mm high, subglobose to globose. Monocarps with black or dark purple exterior and pink to scarlet endocarp in vivo, 4.1–16.3 cm long, 0.6–1.2 cm wide, 0.6–1.1 cm thick, narrowly oblong, torulose to moniliform, somewhat falcate, apex rounded to a distinct beak up to 5 mm long, base contracted into a stipe 4–20 mm long, 2–6 mm thick, obliquely wrinkled, finely verrucose; pericarp 0.6–1.0 (2.0) mm thick. Seeds 1–7 per monocarp, in a single row, lying parallel to long axis, 9.5–19.8 mm long, 5.5–10.7 mm wide, 5.5–9.8 mm thick, oblong-ellipsoid, circular in cross-section, truncate at micropylar end, rounded at chalazal end, reddish brown to brownish black, smooth or slightly wrinkled, shiny, raphe/antriraphe raised, less distinct around chalazal end, micropylar scar 1.5–3.5 mm long, 1.5–2.5 mm wide, ovate; sarcotesta absent; aril orange to red in vivo, light brown when dried, brushlike, 5.5–9 mm in diameter, 3.9–4 mm high, fleshy, granular.

Phenology

Specimens with flowers have been collected from all months of the year except December, although flowering appears more limited for specimens from the northeastern (February, May, and July) and southeastern (June, August–November) areas of the distribution, perhaps in relation to the more restricted seasonal rainfall patterns of these areas compared to the coast. Similarly, collections have been gathered from the coastal localities with fruits in February, May–June, August, and October–November, but only from November in the northeast, and May and August–October in the southeast.

Figure 11. 

Xylopia rubescens. A Habit with fruit B Inner petal, adaxial surface C Outer petal, adaxial surface D, E Stamens, abaxial view F Staminode, abaxial view G Stigma apex H Inflorescence I Seed, longitudinal view. A from Brenan et al. 8022 (K), B–H from Angus 870 (MO) I from Breteler et al. 10446 (WAG, spirit collection).

Distribution

(Fig. 12). Occurs from Guinea and Liberia in West Africa east to South Sudan and south to Angola, Zambia, and Mozambique at elevations from sea level up to 1690 m. This species occurs in a range of wetland habitats, including gallery and other riparian forests, swamp forest, Raphia swamps, and pond edges.

Local names

Fondé de marais (Aubréville 1511), fondé des rivières, fula-bifum (Bates 561), iyere (Kakwa, Myers 13598), mabama (Gossweiler 8957, Gossweiler s. n.), majindi (Banda, Tisserant 1885), mbowobowo (Kimatengo, Ruffo & Kisena 3235), mtua (Pahouin du Gabon, Fleury 33135), mut (Gossweiler 8747), muyombo (Kiluba de Kabongo, Schmitz 5771), mwengele (Wemba, Brenan & Greenway 8022, Kiswahili or Kirungu, Hopper 1), nitumbo (Gossweiler 8747), ntom (Ntomou, Focho et al. 2010), ntua (Pahouin de Gabon, Fleury 33135), odjobi (Ntoumou, Focho et al. 2010; Yaoundé-boulou, Letouzey 1611), odjobi nzam (Cameroon, Focho et al. 2010), odzobé (Yaoundé, Fleury 33135), odžǖ’ē (Tessmann 1913), ôjobi (Bates 1317).

Figure 12. 

Distribution of Xylopia rubescens. Bolder lines represent country borders, fainter lines lakes and major rivers.

Additional specimens examined

GUINEA. Macenta, Soulakoto, 10 Aug 1949 (st), Adam 5910 (MO, P); Macenta, Tènèmadou 10 Aug 1949 (st), Adam 5911 (MO, P); Macenta+Beyla Prefectures, Simandou Range, 8°33'41"N, 8°53'06"W, 868 m, 23 Mar 2008 (fl buds), Tchinegue 3113 (K). LIBERIA. Troh, Sangwin River drainage, 6 May 1948 (fr), Mayer 150 (US). IVORY COAST. Route de Dabou, Marais de l’Agnéby, 27 Nov 1968 (fl), Aké Assi 10378 (MO); Banco, Aubréville 1511 (BR, P); Assinie dans le Sanvi, Chevalier 16321 bis (P); Abidjan, Banco Forest Reserve, 9 Oct 1974 (fr), de Koning 4070 (WAG—2 sheets), 2 Feb 1975 (fl, fr), de Koning 5296 (WAG), 22 Feb 1976 (fl), 6615 (MO, WAG—2 sheets); Abidjan, 3 km N of Armébé, about 10 km NE of Dabou, c. 5°22'N, 4°19'W, 15 May 1979 (fr on label), de Kruif E 20 (WAG—2 sheets); Abidjan, along Agnéby R., not far from Armébé, about 10 km W of Dabou, 5°21'N, 4°20'W, 21 May 1979 (yg fr), de Kruif 57 (WAG). GHANA. Ankasa Forest Reserve, Mpatabo-Elubo Road, Enti 890 (MO); Atuabo Road near Chrisan, 24 Oct 1973 (st), Enti & Awriah R1136 (K, MO). NIGERIA. Prov. Calabar, Eket District, Stubbs Creek Forest Reserve, 3 May 1951 (fr), Amachi FHI 24311 (K); “Southern Nigeria,” without specific locality s. d. (fl), Kennedy 1960 (A, B, BM, K); Jamieson River, Sapoba, 1935 (fl), Kennedy 2752 (BM); without definite locality, van Meer 985 (WAG); S. Nigeria, Thomewill s. n. (K); Benue Plateau, Jos District, 30 km S of Jos, 9°45'N, 8°50'E, 3 Feb 1972 (fr), Wit & Wit FHI 64927 (K, WAG—2 sheets). CAMEROON. Bitye, Yaunde, 1919 (fl), Bates 1317 (BM, MO); environs de Duala, Jun 1917 (fl, fr), Fleury 33135 (P); Vuneli, 1 Feb 1928 (fl), Hedin 1668 (OWU, P); marecage du Niagoul entre Koumbou et Miambo, 14 Apr 1959 (fl, fr), Letouzey 1611 (K—3 sheets, P); près Akok Bikele, 3 Mar 1962 (fl), Letouzey 4464 (K, P); station du Cacaouer de N’Koemvone, 14 km on the road from Ebolowa to Ambam, 2°49'N, 11°08'E, 11 Apr 1975 (fl), de Wilde 8166 (B, BR, K, MO, P, WAG); Bipindi, Mimfia Bergen, Jan 1903 (fl), Zenker s. n. (F, NY). CENTRAL AFRICAN REPUBLIC. Oubangui, reg. de Yango, Mar 1920 (fl), Allouette s. n. (L); Manovo-Gounda-St. Floris National Park, 9.3 km S of Koumbala Pende confluence on Pende Creek, 8°21'N, 21°14'E, 610 m 15 May 1984 (fl), Fay 6639 (MO, P); Yalinga, 15 Jul 1922 (fl), Le Testu 3998 (BM, P); Waka, bassi[n?] riv. Dangava, 10 May 1925 (fl), Tisserant 1885 (BM, BR, P). SOUTH SUDAN. Equatoria, Yei, Libogo, Khor Ini, 19 Nov 1940 (st), Myers 13586 (K); Libogo, Yei, 27 Nov 1940 (fr), Myers 13598 (K). EQUATORIAL GUINEA. Bioko: Malabo—Luba, Estrada km 46, 3 Nov 1986 (fl, fr), Carvalho 2646 (B, BM, F, FI-T, K—2 sheets, MO, NY, WAG).—Río Muni: Nkolentangan [bei Alén, Tessmann 1913], Span. Guinea-Nintod, Engong, 450 m, 24 Feb 1908 (fl), Tessmann 160 (K). GABON. 5–15 km NW of Ndjolé, Missanga, 0°05'S, 10°45'E, 13 Nov 1991 (fr), Breteler & Jongkind 10446 (WAG—2 sheets); Uboro sur le Ramboué, Chevalier 27105 (P); environs de Libreville, Nov 1898 (fl), Klaine 186 (OWU, P); Bitam, region entre Ogooué et Cameroun, 9 Mar 1933 (fl), Le Testu 9019 (BM, BR, OWU, P); Obour, region entre Ogooué et Cameroun, 1 May 1933 (fl), Le Testu 9095 (BM, P). REPUBLIC OF THE CONGO. NE de Brazzaville, route des falaises de Douvres, village de Gamakala, mare à Sphaignes, 22 Jun 1960 (fl), Descoings 5904 (P); Marais du Djili, près de Brazzaville (M. Congo), Koechlin 5299 (P); champ de ter de Lifuola, mare de Gawa Kala, 12 Aug 1966 (fl), Lissouba 22 (P); Tourbière de Ngamakala, 24 Feb 1973 (fl), Makany 882 (K); Plateau des Cataractes, région de Boko, 4 Aug 1963 (fr), de Nere 404 (P); Route de Brazzaville, forêts du Mayumbe, Jan 1891 (fl), Thollon 4026 (P). DEMOCRATIC REPUBLIC OF THE CONGO. Équateur: Bamania [next to Mbandaka], 1930 or 1934 (fl), Lebrun 1246 (A, B, K).—Haut-Katanga: Left-hand side of Luapula R. to Fort Rosebery, 5 Oct 1947 (fl, fr), Brenan & Greenway 8022 (BM, EA, K—2 sheets, NY, P); a 6.2 km au NNW du Post de Katshupa, Plateau de Kundelungu, forêt galerie de la riviére Luanza, à 500 m de la cource, en lisiére, 1690 m, 28 Oct 1968 (fl), Malaisse 6127 (K, P); Kundelungu, Oct 1950 (fl, fr), Schmitz 3176 (BR).—Haut-Lomami: Kamunza, 25°50'E, 7°02'S, fin Sep 1957 (fl), Schmitz 5771 (BR); Riviére Kilwesi, Prov. Katanga, Terr. Mitwaba, Parc national de l’Upemba, 19 Aug 1948 (fl), de Witte 4121 (WAG—2 sheets).—Kasaï-Oriental: Gandajika, Prov. Kasai, 26 Jun 1956 (fl), Risopoulos 531 (K, WAG).—Kinshasa: Bas-Congo, Kinshasa, Maluku, Lac Vert, 13 Apr 1970 (fl), Breyne 864 (MO).—Kongo Central: Kisantu, 1 Nov 1949 (fr), Callens 2143 (K); Bas-Congo, route Kisantu-Madimba, 20 Sep 1952 (fl), Troupin 2104 (BR); Leopoldville, Territ. Boma, Estuaire du fleuve Congo, 6 Sep 1958 (fl), Wagemans 2000 (K).—Kwango: entre Kwango-Wamba tête de sources de la Mpfulula [ca. 5°10'S, 16°40'E], 700 m, 14 Aug 1944 (fl), Germain 2793 (K).—Lualaba: environs de Kolwezi, Tuissesu Kanamwamfwe, 25°25'114E, 10°37'645S, 22 Aug (fl), Malaisse & Kisimba Kibuye 117 (K).—Tshopo: lac Yandja (Yangambi), 19 May 1944 (st), Louis 16985 (K). UGANDA. Amua River, West Madi, May 1948 (fl), Eggeling E.5775 (K—2 sheets). TANZANIA. Kassanga area, Ufipa District, 4000–4500 ft, 1960 (fl), Hopper 1 (EA, K, TFD); T8, Mbinga District, Kitanda ponds at Ndondo Village–Liparamba at 1180 m, 2 May 1991 (fr), Ruffo & Kisena 3235 (K, TFD). ANGOLA. Sumba, Peco, proximum flumen Zaire (Congo), 0 m, 15 May 1923 (fl, fr), Gossweiler 8747 (BM, K—3 sheets, MO, US); Sumba, Peco, proximum flumen Zaire (Congo), Feb 1925 (fl, fr), Gossweiler 8957 (BM, K, US); Sumba, Peco, proximum flumen Zaire (Congo), Aug 1926 (fl), Gossweiler 9126 or 9126A (B, BM, US); Sumba, Peco, proximum flumen Zaire (Congo), Jul 1926 (fl), Gossweiler s. n. (BM, US); Hochland von Quela, 1200 m, Oct 1938 (fl), Nolde 845 (BM) . ZAMBIA. Northern Province, Chinsali District, Shiva Ngandu, 29 Nov 1952 (fl), Angus 870 (BM—2 sheets, EA, K, MO, NY [as White 870]); Luwinga, 15 May 1958 (st), Angus 1942 (K); Kawambwa, 23 Aug 1957 (fl), Fanshawe 3557 (K); Chinsali, 25 Sep 1967 (fl, fr), Fanshawe F10170 (K); Shiwa Ngandu, 3 Aug 1938 (fr), Greenway & Trapnell 5573 (EA, K); Northern Province, Chinsali District, Chipomo Falls National Monument, along Chimanabuwi River, 11°44'58"S, 32°00'17"E, 1310 m, 17 May 1994 (fr), Harder et al. 3145 (MO), (fr), Harder et al. 3164 (MO); Mwinilunga, 10 Sep 1955 (fl), Holmes 1192 (K); Inono Valley Falls above Mukoma, 3000’, 21 Dec 1954 (fl), Richards 3696 (K); Abercorn District, Kasulo, 5000’, 11 Jan 1955 (fl), Richards 4036 (K); Abercorn District, Lucheche R., Abercorn, 1200 m, 10 Oct 1964 (fl, fr), Richards 19193 (BR, K); Abercorn District, Lunzuwa Falls, 26 Oct 1952 (fl), Robertson 184 (BM, EA, K, P); Kamuswazi River, Tunduma Road, 5000’, 20 Jul 1970 (fr), Sanane 1293 (K); Western Province, Fort Rosebery District, near Samfya Mission, Lake Bangweulu, 30 Aug 1952 (st), White 3165A (K—2 sheets), near Samfya Mission, Lake Bangweulu, 30 Aug 1952 (fr), White 3182 (K); Western Province, Mwinilunga District, tributary of Zambezi River, 4 mi N of Kalene Hill Mission, 20 Sep 1952 (fl), White 3309 (K, MO). MOZAMBIQUE. Dist. Moçambique, adm. Mecuburi-Serra Chinga, no vale entre as duas Chinga 10 e Chinga 2, Aguiar Macedo 3274 (DSM).

Xylopia rubescens is readily recognized by the combination of relatively large leaves, which are often orange-red on the abaxial surface of the leaf in dried specimens, twigs with light gray bark, narrow flowers that are often clustered on leafless portions of twigs, stalked glands on the stigmas, and distinctly moniliform monocarps. Throughout its wide range, it is a wetland species. The orange-red cast to the dried leaves, from which the species epithet is presumably derived, is especially pronounced in young leaves. The stalked glands on the stigmas (Fig. 11g) are unique in the genus. William Hawthorne (personal communication) reported that a gland is present on the adaxial surface of the petiole apex in this species, but this characteristic is not discernible in dried specimens and is perhaps only useful for identifying living plants. Specimens are occasionally misidentified as X. aethiopica, which shares the relatively large and subcoriaceous leaves, narrow flower buds, and torulose monocarps, and which is also occasionally found in wet habitats. Xylopia rubescens differs from X. aethiopica, however, in having short inner petals, larger but fewer (<15 per fruit) monocarps, and seeds with the brushlike aril typical of sect. Neoxylopia.

Xylopia rubescens has a number of taxonomic synonyms, which represent minor variations connected by intermediates among the collections examined in this study. Engler and Diels (1901) separated X. humilis from X. rubescens on the basis of the less prominent vein reticulum of the lower leaf surface, but we found this character to vary widely over the range and to be a function of leaf thickness. Engler and Diels, acknowledging that they had not seen the type material of X. rubescens, distinguished X. klaineana from it on the basis of its thinner leaves that lacked the reddish cast. Le Thomas (1969) reduced X. klaineana to a variety of X. rubescens, but drew a sharper distinction between the two taxa, calling attention, again, to the thinner leaves with more prominent venation on the abaxial leaf surface, and also to the much larger seeds of the type of X. klaineana compared to the type material of nominate X. rubescens. Study of material from the entire distribution, however, revealed that mature fruits of this species, such as those present on the type specimen of X. klaineana, are seldom collected, and that larger seeds are found from scattered localities across the range. While the seeds of the type specimen of X. klaineana are the largest seen for this species (17–20 mm long), they are followed closely, in descending order, by seeds of specimens from Gabon (17–18 mm long, Breteler & Jongkind 10446), Cameroon (15–16 mm long, Fleury 33135), Bioko, Equatorial Guinea (14.6–14.9 mm long, Carvalho 2646), and Ivory Coast (14.5 mm long, de Koning 4070). Smaller seeds from throughout the range are sunken and paler brown, with incompletely formed ruminate endosperm, all characteristics of immature seeds. Thus seed size alone is insufficient for maintaining X. klaineana as a distinct taxon.

The label of the type specimen of Xylopia batesii describes the plant as having a shrub or vine habit. The leaves of the type are rounded to nearly truncate at the base, and the outer petals are gradually tapered. While this combination of characters is not usual for X. rubescens, we found each character to vary independently. For example, the specimen Harder 3145 from Zambia was described as a lianescent shrub but it has cuneate leaf bases, the specimen Gossweiler 6222 from Angola (type of X. gossweileri) has strongly rounded leaf bases but has abruptly narrowed petals and was collected from a tall tree, and the specimen Carvalho 2646 from Bioko has very broad petals (over 3 mm wide at the midpoint), strongly cuneate leaf bases, and was collected from a tree 12–15 m tall.

Xylopia rubescens has the second-widest distribution of any African Xylopia species after X. aethiopica and appears to be a wetland opportunist. It has not been collected from most of the Congo River basin within the Democratic Republic of the Congo, where a suitable habitat would seem to be present. Plant associates reported in Cameroon included Ancistrophyllum sp., Cyrtosperma sp., Gaertnera sp., Gardenia imperialis, Mitragyna sp., Raphia sp., and Rhynchospora corymbosa; in Zambia Garcinia mbulwe, Mitragyna stipulosa, Syzygium elegans, and S. cordatum were noted to be growing with X. rubescens.

Seeds of Xylopia rubescens are eaten and dispersed by three species of hornbills and three species of monkeys in the Dja Reserve of southern Cameroon. Seeds of X. rubescens defecated by hornbills were shown to germinate and at a higher rate than uneaten seeds and seeds recovered from gray-cheeked mangabey fecal samples showed 40% germination when planted (Whitney et al. 1998, Poulsen et al. 2001)

Tessmann (1913) reported that the leaves of this plant (called there Xylopia zenkeri) were used in a former time by Fang people in Equatorial Guinea to make a preparation for the treatment of elephantiasis. The leaves were ground together with those of Dioscorea preussii between pieces of bark and then cooked, the resulting water then administered in an enema.

Xylopia staudtii Engler & Diels, Notizbl. Königl. Bot. Gart. Berlin 2: 298. 1899.

Figs 4A, 13

Xylopicrum staudtii (Engler) Kuntze, Deutsch. Bot. Monatsschr. 21:173–174. 1903. Type. CAMEROON. Southwest Province, Johann-Albrechtshöhe, 1896, A. Staudt 530 (holotype: B!; isotypes: K! [000105614], P! [00169112, 00169113]).

Xylopia mayombensis De Wildeman, Bull. Jard. Bot. État 4: 386. 1914. Type. DEMOCRATIC REPUBLIC OF THE CONGO [“Belgian Congo”]. Kongo Central Province, Ganda-Sundi, 1913, Comte J. de Briey 219 (holotype: BR!; isotypes: BR! [8825421, 8825438, 8825445, 8825506]).

Description

Tree up to 35 (–50) m tall, d.b.h. up to 80 cm, bole straight, slender, with branching stilt roots and small buttresses extending from the base, secondary branches horizontal, forming a conical to rounded crown; bark whitish to orangish gray or gray brown, rough, somewhat scaly. Twigs brown to gray, eventually light gray to light brown, appressed-pubescent, the hairs 0.3–0.4 mm long, soon glabrate; nodes frequently with two axillary branches. Leaf with larger blades 5.1–11.8 cm long, 2.0–5.6 cm wide, subcoriaceous to coriaceous, discolorous, often paler abaxially, oblanceolate to obovate, occasionally elliptic, apex blunt-acuminate, acumen 2–3 mm long, or acute, base cuneate and decurrent on petiole, glabrous adaxially, sparsely sericeous abaxially; midrib impressed to plane adaxially, raised abaxially, secondary veins brochidodromous, 7–11 per side, diverging at 45–70° from the midrib, plane or raised adaxially, strongly raised abaxially, higher-order veins forming a conspicuous reticulum that is slightly raised adaxially and strongly raised abaxially; petiole 2.5–9 mm long, canaliculate, sparsely appressed-pubescent or glabrate. Inflorescences axillary, 1–2 (–3)-flowered, sparsely pubescent to glabrate; peduncle 1 per axil, ca. 0.5–2.4 mm long; pedicels 2 per peduncle, 2.5–7 (–8) mm long, 0.8–1.3 mm thick; bracts 2–4, evenly spaced on pedicel, 1.1–2 mm long, semicircular, occasionally tearing down the center as the inflorescence enlarges, apex rounded, occasionally with a tiny apiculum; buds ovoid, apex obtuse. Sepals spreading at anthesis, 1/4–1/2-connate, 1.6–2.7 mm long, 2.6–3.5 mm wide, coriaceous, broadly ovate to semicircular, apex obtuse to acute, appressed-pubescent. Petals yellow to yellow-orange in vivo, outer petals slightly spreading at anthesis, 5.8–9.6 mm long, 4–5.2 mm wide toward base, 3.5–4.3 mm wide at midpoint, fleshy, ovate, apex acute, appressed-pubescent but with a glabrous patch at base adaxially, velutinous or appressed-pubescent abaxially; inner petals erect to slightly spreading at anthesis, 4.1–8.4 mm long, 2.0–3.2 mm wide toward base, 1.7–2.5 mm wide at midpoint, chartaceous, rhombic to broadly lanceolate, apex acute, base with undifferentiated margin, slightly keeled abaxially, pubescent adaxially, pubescent on apical half and glabrous and verrucose on basal half abaxially. Stamens ca. 100–120; fertile stamens 1.6–2.1 mm long, clavate, apex of connective 0.3–0.5 mm long, shieldlike but center formed into a conical point, overhanging anther thecae, pubescent, anthers 6–7-locellate, filament 0.3–0.5 mm long; outer staminodes 1.4–1.7 mm long, oblong to broadly clavate, apex obtuse to obliquely truncate; inner staminodes 1.7–2.6 mm long, clavate, apex rounded; staminal cone 1.3–2.1 mm in diameter, 0.4–0.9 mm high, concealing only the bases of the ovaries, rim laciniate. Carpels 3–11; ovaries 1.3–2.4 mm long, narrowly oblong, tomentose, stigmas free or loosely connivent with tips spreading, 2.6–4.6 mm long, linear, studded with round tubercles on the side and pubescent toward base. Torus flat, 2.2–3 mm in diameter. Fruit of up to 5 glabrate or sparsely appressed-pubescent monocarps borne on a pedicel 7–13 mm long, 3–8 mm thick, sparsely pubescent to glabrate; torus 6–16 mm in diameter, 4.3–5 mm high, depressed-globose. Monocarps with green exterior and scarlet endocarp in vivo, 3.7–9.8 cm long, 1.2–2.1 cm wide, 1.0–1.7 cm thick, oblong and somewhat falcate, occasionally weakly torulose, apex rounded or with a curved beak or mucro 1.3–3 mm long, base contracted into a stipe 7–15 mm long, 2.5–6 mm thick, finely wrinkled, strongly verrucose; pericarp 0.7–2.5 mm thick. Seeds 1–5 per monocarp, in a single row, lying parallel to long axis, 14–19 mm long, 9–12.9 mm wide, 9–11 mm thick, oblong-ellipsoid, oblong-elliptic in cross section, truncate at micropylar end, rounded at chalazal end, brown to black, smooth, shiny, raphe/antiraphe forming a raised ridge encircling the seed, micropylar scar 1.5–3.5 mm long, 1.5–2.0 mm wide, elliptic to circular; sarcotesta absent; aril bright yellow or orange, rarely pink or violet in vivo, amber-colored when dried, brushlike, 10–14 mm in diameter, 4.8–8 mm high, fleshy, granular.

Phenology

Specimens with flowers and with fruits have been gathered in all months of the year and with fruits from all months except March. In Sierra Leone, “flowers appear during the rains from July to August and fruits are ripe by October” (Savill and Fox 1967); in Ghana, the flowering season is given as June to October, and the fruiting season as January to March (Hall and Swaine 1981).

Distribution

(Fig. 10). Occurs from Sierra Leone to Ghana, and then again from eastern Nigeria east to southwestern Uganda and south to the Cabinda Province of Angola and east-central Democratic Republic of the Congo; high forest and occasionally freshwater swamp forest, at elevations from sea level up to 1350 m. In Sierra Leone, the trees have a preference for moist valleys, and can be weedy in timber regeneration plots (Savill and Fox 1967).

Local names

Diroma (Gossweiler 7992), drehn (Cooper 60, 234), duanan (Ghana, Vigne 982, Hall and Swaine 1981), fofois (Gola, Voorhoeve 19), fondé (Aubréville 38, 66, 1941), niumbi (Kitetela, Germain 7631), nkala (Hauzer 29; Bulu, de Wilde 7941), ntom (Ntoumou, Focho et al. 2010), odjobi (Ntomou, Focho et al. 2010; Letouzey 8178), takon-blu-chu (Cooper 139), yengetomei (Sierra Leone, Savill and Fox 1967).

Figure 13. 

Xylopia staudtii. A Outer petal, adaxial view B Inner petal, adaxial view C Stamen, abaxial view D Carpel E Habit F Fruit G Seed, view of micropylar end H Seed, lateral view I Close-up of inflorescence. A–D from Le Testu 8630 (BM) E, I from Evrard 5212 (BR) F from Reitsma 1071 (WAG) G, H from Reitsma & Reitsma 1168 (BISH).

Additional specimens examined

SIERRA LEONE. Yengetumeh M., Kambin Hangha, 21 Aug 1918 (buds), Aylmer 239 (K); Neaboi Valley, Kambui Forest Reserve, 1 Apr 1955 (fr), Jordan 2024 (K); Gola Forest, Bagbe Line, 21 May 1952 (buds), Small 724 (B, K, MO, P). LIBERIA. Saniquellie, Kitoma, 21 Mar 1959 (st), Adam 16813 (MO), 17 Dec 1969 (fr), Adam 25287 (MO); 20 Oct 1971 (st), Adam 26378 (MO); Kakata, Blazie, 7 Mar 1959 (st), Adam 16733 (MO, WAG); Ganta, 30 km S Ganta, 15 Oct 1975 (fr), Adam 29894 (MO); from vicinity of Firestone Plantations along Dukwia ["Dukwai"] R., Monrovia, 3 Oct 1928 (fl, fr), Cooper 60 (BM, F, GH, K, NY, US, YF), 17 Nov 1928 (fl, fr), Cooper 139 (BM, F, GH, K, NY, PH, US, YF), 23 Feb 1929 (st), Cooper 234 (BM, F, K—2 sheets, NY, PH, US, YF); Firestone Plantation #3, 2 Aug 1926 (fl, fr), Linder 66 (A, K—2 sheets); near Blohni, Blohni River drainage, 28 Apr 1948 (fr), Mayer 97 (US); Bong Range, 200 m, 19 Jul 1960 (fr), Voorhoeve 19 (WAG). IVORY COAST. Abidjan, Aubréville 38 (B, K, P), 66 (K, P, US); Banco, undated (fr), Aubréville 1941 (A, P); forêt du Téké, Adzopé-Abidjan km 73, 5°33'N, 4°03'W, 11 Feb 1969 (fr), Bamps 2044 (BR); Abidjan, Banco Forest Reserve, part N of Route du Rail, 29 Apr 1976 (fr), de Koning 6833 (WAG—3 sheets). GHANA. Tarkwa, Subiri F. R. (Benso), Sept 1951 (fl), Andoh A30/51 (FH 5561) (B, K, NY, P); Neung Forest Reserve (W), Dompim, 16 May 1974 (fr), Enti FE-1315 (K, MO, WAG); Neung Forest Reserve, nr. Bonsa River, Tarkwa Dist., 3 Sept 1981 (fr), Enti FE-2095 (MO); Atewa F. R., 1800’, 25 Feb 1971 (fl, fr), Hall GC 43251 (MO); Western Province, Elubo, approx. 22 km ESE towards Takoradi, along Elubo-Taboradi road, then N 8 km on road to Ankasa Forest Reserve, N of Ankasa River, 05°17'N, 02°45'W, 80 m, 14 Jul 1995 (fl, fr), Harder et al. 3406 (MO); Abosso, Aug 1926 (fl), Vigne 982 (K, P). NIGERIA. Southern Nigeria, Central Province, 1931 (fl), Rosevear C.21 (K). CAMEROON. East Province, Department Haut-Nyong, Dja Reserve, Bouamir Research Area, 90 km SE of Akonolinga, 03°12'N, 12°49'E, 640–700 m, 24 Aug 1994 (fl), Fogiel 864 (MO—2 sheets); 22 km à l’Ouest de Masea (village situé à 50 km au SSW de Yokadouma, 4 Jul 1963 (fl), Letouzey 5404 (P); Mebemonko, 20 km NO d’Oveng, 24 Oct 1966 (fl, fr), Letouzey 8178 (K, P); près Nteigne, Pk 108, Route Mintom–Mbalam, near Djoum, Jan 1973 (fl), Letouzey 11854 (K); colline a l’ENE de Mbalam 140 km ESE de Djoum près Souanke-Congo, 20 Jan 1973 (fl, fr), Letouzey 11865 (BR, K—2 sheets, P); Übergangs- und Kampfgebiet gegen die Savanne an der Nord-grenze der Hylaea südlich des Sanaga zwischen Jaunde und Dengdeng unweit der Vereinigung von Lom (Sanaga) und Djerem, etwa 88 km NO Jaunde, Feb 1914 (fl), Mildbraed 8171 (K); Southwest Province, forested lower slopes of Mt. Cameroon above Batoke, 4°05'N, 9°05'E, 300–600 m, 24 Apr 1984 (fl), Thomas 3463 (B, K, MO); Prov. Southwest, Takamanda Forest Reserve, footpath from Mbilishi to Kaluma, 6°15'N, 9°26'E, 650 m, 1 May 1987 (fr), Thomas et al. 7401 (MO); Station du Cacaoyer de N’koemvone, 11 km on the road from Ebolowa to Ambam, 2°49'N, 11°08'E, 31 Jan 1975 (fl), de Wilde 7941 (B, BR, K, MO, P); Station de Cacaoyer de N’Koemvone, 14 km on the road from Ebolowa to Ambam—track crossing the Mvila river, 2°49'N, 11°06'E, 4 Mar 1975 (fl), de Wilde 8029 (B, K, MO); South Province, hill above Nlonacko near village Ebianemeyong, c. 2°26'N, 10°21'E, 500 m, 12 Dec 1998 (fl), de Wilde et al. 12161 (MO); Mimfia, Mar 1913 (fl), Zenker 246 (B, G, GH, M, MO, P, US, WAG); Bipinde, 1908 (fl), Zenker 3653 (BM, F, G, K, L, M, MO, US, WU), Bipinde, Mimfia, Aug 1909 (fl), Zenker 3953 (BM, F, G, K, L, M, MO, P, WU); Bipinde, 1903 (fl), Zenker 4862 (B, BM, G, K, L, M, MO, P, PR, US). EQUATORIAL GUINEA. Río Muni: Près de la frontière gabonaise, chantier forestier à l’est de Cogo, 1°05'N, 10°00'E, 3 May 1989 (bud), McPherson 14003 (MO); Bebai, Campo-gebiet, Weg u Tkum [locality is in NE corner of modern Equatorial Guinea (Tessmann 1913)], 18 Nov 1908 (fl), Tessmann 644 (K). GABON. Estuaire: S of Estuaire du Gabon along Remboué River, British Gas site, 00°12'S, 10°01'E, 10 m, 11 Jan 1991 (fl, fr), McPherson 15113 (MO); côté plantation Sogacel 3 km N de Ndouaniang, 12 Aug 1984 (fl, fr), Wilks WIL 991 (WAG—2 sheets).—Haut-Ogooué: Plateau Batéké National Parc, 02°06'59"S, 14°04'03"E, 421 m, 26 Feb 2003 (fr), Niangadouma & Walters 144 (MO, WAG).—Ngounié: new rd from Mouila to Yeno, 5 km either side of Kembela village, 1°42'S, 11°23'E, 20 Jul 1986 (fl, fr), Thomas & Wilks 6515 (K, MO, P).—Nyanga: région du Nyanga, Inganga, Mayombe Bayaka, 20 May 1914 (fl), Le Testu 1748 (BM, MO, P, US); forêt du Mayombe Bayaka, près de Tchibanga, 10 Dec 1914 (fl), Le Testu 1913 (BM, K—2 sheets, MO, P); chantier CEB, 35 km SW of Doussala, 2°30'S, 10°30'E, 19 May 1985 (fl), Reitsma et al. 1071 (MO, NY, RSA, WAG); chantier CEB, ca. 50 km SW of Doussala, 2°36'S, 10°35'E, 14 Jun 1985 (fr), Reitsma & Reitsma 1168 (BISH, MO, NY, RSA).—Ogooué-Maritime: Toucan, ca. 01°47'S, 09°53'E, 9 Jun 2002 (fl, fr), Bourobou Bourobou et al. 707 (MO—3 sheets).—Ogooué-Ivindo: M’Passa Field Station, near Makokou on Riviere l’Ivindo, 8 Jul 1981 (fr) Gentry 33219 (MO); Ile Ipassa, Makokou, 17 Jun 1972 (fr), Hladik 2334 (P); Monts Iboundji, 27 Dec 1930 (fl), Le Testu 8630 (BM, BR, P).—Woleu-Ntem: Oyem, région entre Ogooué et Cameroun, 9 Sep 1933 (fl), Le Testu 9287 (BM, BR, K—2 sheets, P).—Province unknown: Billagone, 100’, 22 May 1938 (fl), Thomson 2 (K). REPUBLIC OF THE CONGO. Route du chantier de Boungolo (Pointe-Noire), 31 Jan 1966 (fl), Farron 4892 (K, P). DEMOCRATIC REPUBLIC OF THE CONGO. Équateur: Entre Bokatola and Bikoro, Sep 1930 (fl), Lebrun 1425 (BM, K, MO, NY, RSA, US).— Ituri: Ituri District, Lodjo, SW of Lodjo village, 2°03.09'N, 29°59.51'E, 1080 m, 26 Jan 2011 (fr), Bytebier et al. B 3367 (K, MO).—Kongo Central: Kisafu [Maduda], 10 Oct 1951 (fr), Hauzer 29 (BR).—Sankuru: Katako-Kombe, Rubber Plantation, Jun 1952 (fr), Germain 7631 (BR).—Sud-Kivu: Mukono, Terr. Mwenga, 8 Jul 1959 (fl, fr), Leonard 4877 (BR).—Tshopo: Tsangi Terr., Yangambi, 120 m, 5 Mar 1952 (fl), Toussaint 918 (K).—Tshuapa: Piste Yalikungu-riv. Tshuapa, Terr. Ikela, 25 Nov 1958 (fl), Evrard 5212 (BR, K). ANGOLA. Mayumbe, M’bulu hills, source of N’Zanga River, 11 Apr 1919 (fl, fr), Gossweiler 7992 (BM, BR, K—3 sheets). UGANDA. Impenetrable Forest, Kigezi, Apr 1946 (fl), Butt 45 (ENT, not seen, photo at K); [U2], Rukungiri District, Kayonza, Bwindi forest, Ishasha Gorge, 0°53’–1°08'S, 30°25’–30°35'E, 1350 m, Apr 1998 (fl), Hafashimana 0504 (K).

Xylopia staudtii is the tallest of any Xylopia species, becoming a canopy tree of up to 50 m. The elaborate stilt roots of this species, described in detail by Jeník (1970), consist not only of adventitious stilt roots emerging from the trunk up to one meter above the ground, but also stilted pneumatophores (“peg roots”) that arise from lateral roots up to 10 m distant from the tree trunk. These striking roots suggest adaptation to swamp forests, although the species is not restricted to such habitats.

With its broad flower buds, Xylopia staudtii is most similar to Xylopia africana, also sharing with that species the oblong thick-walled monocarps and large seeds with a brushlike aril. In fact, many collections of X. staudtii made by Zenker in Cameroon were distributed as X. africana. The lone taxonomic synonym, Xylopia mayombensis De Wild., was based on a specimen with petals at the larger end of the range of petal size for X. staudtii but is not otherwise exceptional for the species.

Sunderland et al. (2003) reported X. staudtii to be a dominant tree in lowland (300–500 m), mid-elevation (500–800 m), and montane (800–1500 m) forests of the Takamanda Reserve, having the second-highest relative density and the fourth-highest basal area of all tree species sampled in montane forest plots. The seeds of X. staudtii have been reported as a food item for two hornbill species (Whitney et al. 1998), four species of mangabeys and guenons (Sourd and Gautier-Hion 1986, Poulsen et al. 2001), and mandrills (Lahm 1986). The nutrient analysis of the arils of X. staudtii by Sourd and Gautier-Hion (1986) showed high levels of lipids and proteins, suggesting that the species provides a high-value food resource to these dispersers and perhaps others. Some seeds defecated by gray-cheeked mangabeys and by hornbills germinated (Whitney et al. 1998, Poulsen et al. 2001).

Xylopia Section Ancistropetala (Engler), D. M. Johnson & N. A. Murray, Syst. Bot. 42(2): 221. 2017.

Artabotrys section Ancistropetalum Engler, Monogr. afrik. Pflanzen-Fam. 6: 71. 1901.

Type

Artabotrys auranti[i]odorus (De Wildeman & T. Durand) Engler [=Xylopia aurantiiodora De Wildeman & T. Durand].

Description

Nodes with a branch from a single axillary bud; outer and inner petals linear, similar in length; inner petals with differentiated fleshy basal margins (Fig. 14E, I); anther connectives conical to globose at apex, not overhanging anther thecae: staminal cone absent; carpels 3–5, stigmas free, not connivent; aril fimbriate, enveloping seed; seed coat smooth, sarcotesta absent. Three species in Tropical Africa.

Notes

Section Ancistropetala comprises species restricted to wet forests of western and central Africa. Species of the section are set apart from all other members of the genus by the fimbriate membranous orange arils and conical to globose anther connectives. Differentiated inner petal margins are present outside of sect. Ancistropetala only in the species Xylopia toussaintii, X. gilbertii, and X. flamignii of section Stenoxylopia (Fig. 23D, G), but these species have a distinct staminal cone, anther connectives that are truncate at the apex, and seeds with an orange sarcotesta, and the seeds lack arils.

Figure 14. 

Xylopia quintasii, X. congolensis, and X. aurantiiodora. A–F X. quintasii A Seed, lateral view B Outer petal, adaxial view C Monocarp, lateral view D Flower, lateral view E Inner petal, adaxial view F Leaf G X. congolensis, flower, lateral view. H–K X. aurantiiodora H Leaf I Inner petal, adaxial view showing tooth J Flower, lateral view K Monocarp, attached to pedicel L Outer petal, adaxial view. A, C from Reitsma 1423 (WAG) B, D–F from de Wilde et al. 9156 (WAG) G from Tutin 80 (MO) H, K from Harris 752 (MO) I, J, L from Harris & Fay 1846 (MO).

Xylopia aurantiiodora De Wildeman & T. Durand, Ann. Mus. Congo, Sér. 2, Bot. 1(1): 4. 1899.

Fig. 14H–K

Artabotrys aurantiiodorus [“aurantiodorus”] (De Wildeman & T. Durand) Engler, Monogr. afrik. Pflanzen-Fam. 6: 76. 1901. Type. DEMOCRATIC REPUBLIC OF THE CONGO [“Belgian Congo”]. Équateur Province [“Région III”], Mbandaka [“Coquilhatville”], 24 Jan 1896, A. Dewèvre 660 (holotype: BR!; isotypes: BR! [8824271, 8824677, 8824684, 8824691]).

Xylopia bequaertii [“bequaerti”] De Wildeman, Pl. bequaert. 1: 469–470. 1922. Type. DEMOCRATIC REPUBLIC OF THE CONGO [“Belgian Congo”]. Tshopo Province, Kisangani [“Stanleyville”], bords boisés de la Tshopo, 27 Feb 1915, J. C. C. Bequaert 6994 (holotype: BR!).

Description

Tree or shrub 2–10 m tall, d.b.h. up to 30 cm; bark light colored. Twigs brown to gray, glabrous or with sparse hairs 0.2–0.3 mm long, usually marked by two ridges decurrent from each petiole base, epidermis eventually exfoliating. Leaf with larger blades 6.3–11.1 cm long, 2.5–4.7 cm wide, chartaceous to subcoriaceous, discolorous, the lower surface tan-colored, elliptic to oblong-elliptic, occasionally oblanceolate or obovate, apex rounded, obtuse, or acute, occasionally emarginate, base cuneate and decurrent, glabrous adaxially, glabrous or with a few scattered hairs abaxially; midrib plane to slightly raised adaxially, raised and somewhat keeled abaxially, secondary veins brochidodromous, 10–14 per side, diverging at 60–70° from the midrib, these and higher-order veins forming a raised reticulum on both surfaces; petiole 2.5–7 mm long, shallowly canaliculate, glabrate or sparsely pubescent. Inflorescences axillary, 1–5-flowered, occasionally with two pedicels borne on a common peduncle, glabrous to sparsely pubescent; peduncle 1.5–2.0 mm long; pedicels 3.5–7.1 mm long, 0.5–1.0 mm thick; bracts 2–3, the uppermost often just beneath the sepals, caducous, 1.1–1.5 mm long, semicircular, apex rounded; buds panduriform, apex obtuse. Sepals free and somewhat imbricate at the base, 1.5–2.1 mm long, 1.9–2.4 mm wide, coriaceous, semicircular to triangular, apex apiculate, pubescent abaxially with hairs extending beyond margins to form cilia. Petals white or pale yellow to greenish yellow in vivo; outer petals erect with the apices slightly spreading at anthesis, 8.9–12 mm long, 2.4–3.5 mm wide, 1.8 mm wide at midpoint, fleshy, ligulate-lanceolate, apex obtuse, pubescent except for glabrous center of basal concavity adaxially, buff-brown pubescent abaxially; inner petals with apices divergent, 9.3–11.2 mm long, 1.2–2.3 mm wide at base, ca. 0.8 mm wide at midpoint, narrowly oblong, apex obtuse, base with differentiated margin, with a truncate tooth 0.8–1.1 mm long overhanging basal concavity, densely puberulent on both surfaces except for the glabrous differentiated margins and basal concavity. Stamens 40–60; fertile stamens ca. 1.8 mm long, oblong, apex of connective 0.2–0.3 mm long, globose, not overhanging the anther thecae, papillate, anthers 6–8-locellate, filament ca. 0.5 mm long; outer staminodes ca. 1 mm long, broadly clavate, apex rounded, emarginate, or bilobed; inner staminodes absent; staminal cone absent. Carpels 3–5; ovaries 0.7–1 mm long, globose, pubescent; stigmas discrete, not connivent, 0.6–0.8 mm long, narrowly oblong, glabrous except for fine setae at the apex. Torus flat, 1.5–1.8 mm in diameter. Fruit of up to 3 glabrate monocarps borne on a pedicel 6.5–10 mm long, 1.2–1.8 mm thick, slightly curved, sparsely pubescent to glabrate; torus 2.8–4 mm in diameter, 2–2.5 mm high, depressed-globose. Monocarps green in vivo, 3.3–6.5 cm long, 0.7–0.9 cm wide, 0.7–0.8 cm thick, finger-shaped to narrowly oblong, strongly torulose, apex acute to rostrate, beak up to 5 mm long, base abruptly contracted into a stipe 5.5–9.5 mm long, 2–3 mm thick, wrinkled and somewhat flattened, striate and somewhat shining; pericarp 0.1–0.4 mm thick. Seeds 1–4 per monocarp, in a single row, parallel or slightly oblique to long axis, 13.3–21 mm long, 5.5–8.3 mm wide, 5.5–7.5 mm thick, narrowly ovoid to oblong, circular to elliptic in cross-section, obliquely truncate at micropylar end, distinctly pointed at the chalazal end, light reddish brown, smooth, raphe/antiraphe not evident, micropylar scar 2.7–4.5 mm long, 2–2.5 mm wide, elliptic; sarcotesta absent; aril red in vivo, orange-brown when dried, fimbriate, extending the length of the seed, membranous, smooth.

Phenology

Specimens with flowers have been collected from January to March and from May to November; fruits have been collected in May, June, August, and September.

Distribution

(Fig. 15). Xylopia aurantiiodora is found in the Congo River basin in the Democratic Republic of the Congo, the southern Central African Republic, and eastern Cameroon, with disjunct occurrences in the Cabinda Province of Angola and near Lolodorf in southern Cameroon. It grows in riparian forest, on riverbanks, and in inundated forest, from near sea level up to 470 m.

Figure 15. 

Distributions of Xylopia aurantiiodora, X. congolensis, and X. quintasii. Bolder lines represent country borders, fainter lines lakes and major rivers.

Local name

Gongo-sange (Bangala, Robyns 465).

Additional specimens examined

CAMEROON. Eastern Province, west bank of the Sangha River, 02°23'N, 16°10'S, 22 May 1988 (fr), Harris & Fay 752 (K, OWU); Est, west bank of Sangha River opposite Ndakan camp and 2 km S, 02°21'N, 16°08'E, 12 Feb 1989 (fl), Harris & Fay 1846 (GH, MO); Mbekou près Moloundou, 17 Oct 1949 (fl), Letouzey SRFK 1374 (P); env. de Lolodorf, 1919 (fl), Rouyer s. n. (L). CENTRAL AFRICAN REPUBLIC. Sangha-Mbaere, west bank of Sangha River, opposite Bayanga, ca. 200 m upstream, 02°55'N, 16°21'E, 20 Feb 1991 (fl), Harris 2750 (OWU); bord. Riv. Ouaka [“Waka”] 30 km N Bambari, 29 Jan 1923 (fl), Tisserant 936 (BM, P, US). DEMOCRATIC REPUBLIC OF THE CONGO. Bas-Uele: Terr. Bambesa, bord de l’Uéle, 20 Feb 1956 (st), Gerard 2162 (WAG).—Équateur: Eala, 7 Jul 1933 (fl), Corbisier-Baland 1687 (BM, K, MO, P, US); Scierie de Loukoléla, 26 Aug 1912 (st), Chevalier 28289 (P); Eala, Couteaux 425 (K, P); Botsima, parc au layon central, 1°09'S, 21°57'E, 28 Mar 1991 (fl), Dhetchuvi 1067 (BR); District de la Tshuapa [Basankusu, fide Boutique 1951b], Jul 1934 (fl), Dubois 485 (K, MO, P); district de la Tshuapa, Aug 1938 (fr), Dubois 972 (K); Popolo, forêt inondée de la Mongala, 10 Aug 1955 (fr), Evrard 1594 (BR); Popolo, forêt marécageuse de la Mongala, Evrard 1658 (P); Territ. Bolomba, R. Busisa or Busira, en amont de Isalo, Oubangui, 2 Mar 1958 (bud), Evrard 3601 (K); Territ. Monkoto, river Yenge, 25 km from mouth, 2 Aug 1958 (bud), Evrard 4431 (K); Territ. Bokota, Watsi Kengo, inundated forest of the Salonga (hautes eaux), 14 Nov 1957 (fl), Evrard 2964 (K); Wangata, Aug 1930 (fl), Lebrun 922 (A, K, MO, P, PR); entre Eala et Boyeka, rive droite de la Ruki, 8 Sep 1925 (fl, fr), Robyns 465 (B, BR—2 sheets, K); environs de Mbandaka [“Coquilhatville”], 15 Sep 1925 (fr), Robyns 580 (A, B, K—2 sheets, P).—Maniema: Secteur Bangengele, Parc National Proposé de la Lomami, ca. 3.9 km au NNO de Katopa (en ligne directe) en descendant la rivière Lomami, 02°43'00"S, 025°05'03"E, 430 m, 3 May 2015 (fl), Gereau et al. 7632 (MO).—Mongala: Monza (village) along the Loika (Itimberi), 02.0491°N, 022.743°E, 335 m, 30 Jun 2009 (fr), Stoffelen 453 (MO).—Nord-Ubangi: entre Banzyville et Yakoma (Ubangi), Feb 1931 (fl), Lebrun 2167 (K, MO, P).—Tshopo: Terr. Isangi, Yangambi, île Tutuku, Jul 1963 (fl) Bolema 1192 (K, P, WAG—2 sheets); 0°26'S, 25°28'E, Ubundu, rives du fleuve Zaire et îles en amont d’Ubundu, 12 Mar 1978 (fl), Lejoly 2915 (BR); près d’Ubundu, bord d’une île sur le Zaire, 11 Mar 1978 (fl), Lisowski 47959 (K); env. de Yangambi, bord du Zaire au pied de la Falaise, 28 Apr 1979 (bud), Lisowski 52352 (K); Yangambi, 17 Aug 1937 (fl), Louis 5804 (B, BM, F—2 sheets, K, MO, NY, P, US); Yangambi, 9 Feb 1938 (fl), Louis 7839 (B, K, MO, P, US), Yangambi, 21 Mar 1938 (fl), Louis 8542 (MO); Yangambi, 28 Jul 1938 (fl), Louis 10543 (BM, EA, FI-T, K, P), Yangambi, 3 Aug 1938 (fr), Louis 10671 (BM, EA, FI-T, K, P); Yangambi, 13 Aug 1938 (fr), Louis 10790 (BM, EA, FI-T, K, P), Yangambi, 29 Jan 1939 (fl), Louis 13464 (BM, K); Yangambi, île Tutuku, 31 Jul 1939 (fl), Louis 15674 (K, MO, P, US). ANGOLA. Maiombe, banks of river Luali, Gossweiler 7168 (BM, COI-00067909); banks of the river Luali at Sera, Maiombe, 7 May 1917 (fl), Gossweiler 7169 (BM, COI-0067910); Maiombe Portuguesa, Sera, proximum flumen Luali-Chiloango, Jun 1924 (fl, fr), Gossweiler 9006 (B, BM, K).

Xylopia aurantiiodora differs from X. congolensis and X. quintasii in having a prominent tooth on the inner surface of the inner petals (Fig. 14I), strongly striate monocarps that are acute at the apex, and larger pointed seeds. The tooth of the inner petal is especially useful for identification, because it appears early in petal development and is visible even in young buds. The connivance of the bases of the inner petals is more pronounced in this species than in other species of the genus and is reminiscent of Artabotrys; presumably on this basis, X. aurantiiodora was moved to Artabotrys by Engler and Diels (1901), who erected a special section for it. Xylopia aurantiiodora also differs from X. congolensis and X. quintasii in both habit and habitat, being a riverine tree reaching only 10 m in height, while the other two species are trees of upland forest commonly reaching a height of 20 m or more. Associated species of X. aurantiiodora mentioned on herbarium labels include Irvingia smithii, Trichilia retusa, and Uapaca heudelotii. The species epithet marks the field observation of Dewèvre that the flowers had the scent of citrus flowers.

We treat Xylopia bequaertii as a taxonomic synonym of X. aurantiiodora, as previous authors have (e.g. Boutique 1951b), observing only that, in his original description of X. bequaertii, De Wildeman (1922) made no mention of X. aurantiiodora but instead contrasted X. bequaertii with X. striata Engler, drawing attention to floral differences between the two species as well as the larger number of secondary veins in the leaves of X. bequaertii.

Xylopia congolensis De Wildeman, Ann. Mus. Congo, Sér. 5, Bot. 1: 41–42. 1903.

Fig. 14G

Type

DEMOCRATIC REPUBLIC OF THE CONGO [“Belgian Congo”]. Kongo Central Province, Inkisi-Kisantu [“Kisantu”], 1900, J. Gillet 812 (lectotype, here designated: BR!; isotypes: BR! [0000008824707, 0000008824714, 0000008824721, 0000008824769, 0000008824776]).

Description

Tree up to 20 m tall, d.b.h. up to 50 cm; bark medium brown to red-brown, flaking. Twigs brown to shiny reddish brown or orange-brown, eventually light gray to gray-brown, glabrous, the bark sometimes exfoliating in strips, often marked with sharp ridges decurrent from both sides of petiole base. Leaf with larger blades 6.9–11.5 cm long, 2.6–4.4 cm wide, subcoriaceous to chartaceous, discolorous, oblanceolate to narrowly elliptic, apex acuminate, the acumen 4–11 mm long, base cuneate and decurrent, glabrous on both surfaces; midrib slightly impressed to plane adaxially, raised and sharply keeled abaxially, secondary veins brochidodromous, 9–12 per side, diverging at 45–75° from the midrib, often festooned with extra loops on the outside, secondary and higher-order veins indistinct to slightly raised adaxially, raised abaxially; petiole 3–8 mm long, shallowly canaliculate, glabrous or with a few hairs. Inflorescences axillary or from the axils of fallen leaves, 1–4-flowered, appressed-pubescent to glabrate; pedicels arising from axils independently, rarely from a common peduncle ca. 2 mm long, pedicels 3.4–6.7 mm long, 0.7–1.0 mm thick, often curved; bracts 2–4, caducous, rarely persistent, 0.8–1.5 mm long, semicircular to lunate, apex rounded; buds narrowly oblong, apex obtuse. Sepals slightly spreading at anthesis, free or 1/8–1/6-connate, 1.5–2.5 mm long, 2.0–2.5 mm wide, coriaceous, triangular to triangular-ovate, apex acute to obtuse, appressed-pubescent abaxially. Petals white, pale green, or yellowish white in vivo; outer petals slightly spreading at anthesis, 12.7–22 mm long, 2.1–3.3 mm wide at base, 1.0–2.3 mm wide at midpoint, coriaceous or slightly fleshy, linear-ligulate, apex obtuse, densely puberulent except for small glabrous patch at base adaxially, appressed-pubescent abaxially; inner petals more or less erect at anthesis, 10.3–18.6 mm long, 0.9–1.0 mm wide at base, 0.6–0.9 mm wide at midpoint, coriaceous or slightly fleshy, linear or sometimes slightly spatulate, apex obtuse, base with differentiated fleshy or membranous margins, densely puberulent on both surfaces except in basal concavity and on fleshy margins. Stamens 48–61; fertile stamens 1.5–1.8 mm long, oblong, apex of connective 0.4–0.5 mm long, conical, not overhanging anther thecae, long-papillate, anthers 8–10-locellate, filament 0.3–0.5 mm long; outer staminodes 1.2–1.5 mm long, oblanceolate, apex obtuse; inner staminodes apparently absent; staminal cone absent. Carpels 3–5; ovaries 1.0–1.6 mm long, oblong, densely pubescent, stigmas discrete, not connivent, 0.4–0.7 mm long, narrowly oblong to clavate, glabrous. Torus flat, 1.7–2.1 mm in diameter. Fruit of up to 3 glabrate monocarps borne on a pedicel 12–14.8 mm long, 1.6–2 mm thick, glabrate or with scattered hairs; torus 3–4.7 mm in diameter, 2.5-3 mm high, globose. Monocarps 3.7–4.6 cm long, 0.6–0.9 cm wide, 0.8–1.0 cm thick, linear-oblong, weakly torulose, apex rostrate, the beak ca. 2.5 mm long, base contracted into a more or less distinct stipe ca. 6 mm long, 2.4–2.5 mm thick, longitudinally wrinkled and obliquely striate, faintly verrucose; pericarp ca. 0.5 mm thick. Seeds up to 5 per monocarp, in a single row, lying parallel to long axis, 10.4–11.2 mm long, 6.8–7.0 mm wide, ca. 6.7 mm thick, ellipsoid, elliptic in cross-section, truncate at micropylar end, rounded or obtuse at chalazal end, brown, smooth, dull to shiny, raphe/antiraphe not evident, micropylar scar 2.7–4 mm long, 3–3.7 mm wide, roughly circular; sarcotesta absent; aril color in vivo unknown, straw-colored when dried, fimbriate, extending the length of the seed, membranous, smooth.

Phenology

Specimens with flowers have been collected in February and once in August, with large buds in January, and with fruits in October.

Distribution

(Fig. 15). Gabon and southwestern Democratic Republic of the Congo, occurring in evergreen rainforest at 200–500 m.

Local names

Lukanga (Hauzer 18), mvouma (Fang, Hladik 1689 part A, part C), ngambo (Bakota, Hladik 1689 part C).

Additional specimens examined

GABON. Nyanga: Mayombe bayaka, Tchibanga, région du Nyanga, 2 Feb 1915 (fl), Le Testu 2006 (A, BM, MO—2 sheets, P).—Ogooué-Ivindo: SEGC, 11 Jan 2017 (buds), Abernethy s. n. (OWU); Ipassa, vieille route, Makokou, 500 m, 29 Feb 1972 (fl), Hladik 1689 part A (P); Ipassa, 10 km S of Makokou, 29 Feb 1972 (fl), Hladik 1689 part C (US); Station d’Etudes des Gorilles et Chimpanzés, forêt de l’Aeroport, 2 Feb 1993 (fl), Tutin 80 (MO); Reserve de Lopé-Okanda, 0°25'S, 11°30'E, 20 Dec 1990 (tiny buds), White [series 2] 285 (MO), Reserve de Lopé-Okanda, 0°25'S, 11°30'E, 10 Feb 1991 (fl), White [series 2] 345 (MO); Lope Reserve, Pothos death site, Aug 1993 (fl), White 960 (MO). DEMOCRATIC REPUBLIC OF THE CONGO. Kongo Central: Kisafu (Maduda), Oct 1951 (fr), Hauzer 18 (BR).

In the herbarium this species is separable with difficulty from X. quintasii s. s. but is more readily distinguished in the field. The flush of leaves on new growth is white (L. White and K. Abernethy, personal communication), and in central Gabon the flowers appear mostly in February. The most striking quantitative difference is in the size of mature flowers, with the outer petals of X. congolensis sometimes exceeding 20 mm in length. There are, however, small differences that can be discerned in herbarium material. The leaves of X. congolensis tend to be proportionally narrower than those of X. quintasii and are usually glabrous; the decurrent ridges on the twigs are raised and persistent, the pedicels are relatively short, and the bracts are caducous well before anthesis. In the Lopé Reserve field site, both species are present and have maintained discrete phenologies over a period of many years (K. Abernethy and E. Bush, personal communication). Associates of X. congolensis mentioned by collectors are species of Parinari, Treculia, and Pentadesma (Hauzer 18), and understory Marantaceae (White [series 2] 285).

Boutique (1951b) expressed the opinion that Xylopia congolensis was not necessarily conspecific with X. quintasii, calling attention to the smaller seeds and shorter aril of the type specimen. While the fruits and seeds on the type specimen of X. congolensis are immature, thus accounting for these differences, the specimen shows vegetative features that place it with a number of specimens from Gabon.

Xylopia quintasii Engler & Diels, Monogr. afrik. Pflanzen-Fam. 6: 62. 1901.

Figs 3C, 4C, 14A–F

Xylopia striata Engler, Bot. Jahrb. Syst. 34: 160. 1904. Type. CAMEROON. South Province, Bipindihof, Jan 1903 (fr), G. A. Zenker 2663 (lectotype, here designated: B!; isolectotypes: BM! [000511005, right hand portion of sheet], K! [001096587], P!).

Xylopia lanepoolei Sprague & Hutchinson, Kew Bull. Misc. Inform. 1916: 160–161. 1916. Type. SIERRA LEONE. Western Area, Headquarters District, Heddles Farm, Apr 1914, C. E. Lane-Poole 210 (lectotype, here designated: K! [000380211]; isolectotype: K, n. v. [spirit collection 15057.000]).

Polyalthia mayumbensis Exell, J. Bot. 64: Suppl. 4. 1926. Type. ANGOLA [“Portuguese Congo”]. Cabinda Province, Buco Zau, Mayumbe, 28 Nov 1916 (fl), J. Gossweiler 6845 (holotype: BM! [000511084]; isotype: COI! [00004887]).

Type

SAO TOME & PRINCIPE. “Insel St. Thomé, bei Angolares um 100 m. ü. d. M., Jan 1886, F. Quintas 3 (lectotype, here designated: K! [000199059]; isolectotype: COI).”

Description

Tree up to 42 m tall, commonly 10–30 m, d.b.h. up to 75 cm, bole cylindrical, up to 37 m high, with narrow thin buttresses at the base, secondary branches horizontal, forming a small (3–5 m high) flat to conical crown; bark brown to reddish brown, scaly and peeling. Twigs light to dark brown, sometimes orange- or red-tinged, eventually light gray to brown, glabrous or sparsely pubescent, the hairs 0.1–0.2 mm long, soon glabrate, usually with bark exfoliating, sometimes marked with ridges decurrent from both sides of petiole base. Leaf with larger blades 6.0–11.9 cm long, 2.6–5.5 cm wide, subcoriaceous to chartaceous, discolorous with the lower surface often tan-colored, obovate to oblanceolate, occasionally elliptic, apex short-acuminate, the acumen 1.5–6.5 mm long, occasionally obtuse, rounded or emarginate, base cuneate and decurrent, glabrous adaxially, sparsely appressed-pubescent to glabrate abaxially; midrib plane to impressed adaxially, raised and somewhat keeled abaxially, secondary veins brochidodromous, 7–12 per side, diverging at 60–70° from the midrib, secondary veins slightly raised adaxially, raised abaxially, higher-order veins indistinct or occasionally slightly raised or impressed adaxially, usually forming a raised reticulum abaxially; petiole 2.5–6.5 mm long, shallowly canaliculate, sparsely pubescent to glabrate. Inflorescences axillary or from the axils of fallen leaves, 1–7-flowered, appressed-pubescent; peduncle 1 per axil, 2.6–2.8 mm long or pedicels arising directly from axil or both; pedicels 3–4 per peduncle, 6.5–8.5 mm long, 0.5–0.7 mm thick; bracts usually 3, sometimes 2 or 4, evenly spaced along length of pedicel, uppermost often persistent, but lower usually caducous, 1.2–1.5 mm long, lunate to semicircular, apex rounded; buds panduriform or narrowly oblong, apex obtuse. Sepals spreading at anthesis, free or only connate at very base, the bases sometimes slightly imbricate, 1.5–1.9 mm long, 1.9–2.4 mm wide, coriaceous, semicircular, triangular or ovate, apex acute to obtuse, pubescent abaxially. Petals pale green, white, or cream-colored in vivo; outer petals bent outward above the base at anthesis, 8–15 mm long, 1.8–2.8 mm wide at base, 1.5–1.8 mm wide at midpoint, coriaceous to slightly fleshy, ligulate, apex obtuse, puberulent except for glabrous patch at base adaxially, appressed-pubescent abaxially; inner petals erect at anthesis, 7.1–13.2 mm long, 0.7–1.5 mm wide at base, ca. 0.6 wide at midpoint, fleshy, linear, apex obtuse, base with differentiated fleshy or membranous margins, densely puberulent on both surfaces except for glabrous concavity and basal margins adaxially. Stamens 50–80; fertile stamens 1.3–1.8 mm long, oblong, apex of connective ca. 0.3 mm long, conical, slightly overhanging the anther thecae, long-papillate, anthers 8–10-locellate, filament 0.4–0.6 mm long; outer staminodes 1–1.3 mm long, broadly clavate to oblanceolate, apex conical; inner staminodes absent; staminal cone absent. Carpels 3–5; ovaries (0.8–) 1.2–1.6 mm long, ellipsoid, pubescent, stigmas discrete, not connivent, 0.3–0.7 mm long, clavate, glabrous except for fine setae at the apex. Torus flat, 1.4–1.9 mm in diameter. Fruit of up to 4 glabrate monocarps borne on a pedicel 8.3–19 mm long, 1.5–2.2 mm thick, glabrate; torus 2.4–4.7 mm in diameter, 1–3.5 mm high, depressed-globose. Monocarps with green exterior, tinged with brown, maroon, or purple, and green endocarp in vivo, 3.5–6.4 cm long, 0.7–1.0 cm wide, 0.6–0.9 cm thick, narrowly oblong, occasionally slightly falciform, torulose, apex obtuse to rostrate, the beak 1.5–4 mm long, base contracted into a more or less distinct stipe 6.5–11 mm long and 1.9–3.5 mm thick, obliquely striate, occasionally verrucose; pericarp 0.2–0.9 mm thick. Seeds up to 5, commonly 3, per monocarp, in a single row, parallel or slightly oblique to long axis, 10–12.5 mm long, 5.5–7 mm wide, 5–6 mm thick, ellipsoid, elliptic in cross-section, truncate at micropylar end, rounded and somewhat wedge-shaped at chalazal end, brown to reddish brown, smooth, shiny, raphe/antiraphe not or only faintly evident, micropylar scar 1.8–3.5 mm long, 2.5–3 mm wide, roughly circular or transversely elliptic; sarcotesta absent; aril red to deep orange in vivo, straw-colored when dried, fimbriate, extending the length of the seed, membranous, smooth.

Phenology

Specimens with flowers have been collected from September to June and with fruits from March to October and in December. In West Africa (Sierra Leone to Nigeria), flowering begins in December and continues until May, while, in central Africa (Cameroon and eastward and southward), flowering begins in September and lasts until February. The fruiting phenology is also offset slightly, with fruits collected in western Africa in March, May, June, July, and October, and fruits in central Africa collected from April to August, and in October and December. The West African pattern is confirmed by Hall and Swaine (1981), who give the flowering period in southern Ghana as December to March and the fruiting period as July to October. In Sierra Leone, flowering is reported to occur from February to April, with ripe fruits following from June to September (Savill and Fox 1967).

Distribution

(Fig. 15). Xylopia quintasii is distributed from Sierra Leone along the coast eastward to Ghana, resuming in southern Nigeria and extending eastward to the southern Central African Republic and southward across Gabon and the westernmost Democratic Republic of the Congo into the Cabinda Province of Angola. It occurs in primary lowland rainforest on a variety of soil types, occasionally in secondary forest or rarely in inundated forest, at elevations of 0–1000 m, although it is most common below 200 m.

Local names

Brala (ébrié, Aubréville 1959), gbay (Cooper 222), gbay-dee (Cooper 372), elo (Service forestier 458), lucanga (Gossweiler 6845), melasomba (Lissongo, Tisserant 527), aghako (Benin, Kennedy 1319), mbonba (Yaounde, Letouzey 5510), muomba (Wilde & Wilde-Duyfjes 1320), mvoma (Pahouin, Fleury 26594), mvǔ’ma (Fang, Tessmann 760, Tessmann 1913), nkala (Lissongo, Tisserant 1786), nzange (Ngwaka, Evrard 813; Lissongo, Tisserant 1786), obaa (Akan, Hall and Swaine 1981), opalifon (Yoruba), kpaini, bajineh, or bajmeh (Mende, Aylmer 202), kpaini (Lane-Poole 210). A number of these common names are also given to other species of Xylopia. The label of Deighton 4153, from a collection made in Sierra Leone in 1946, gives these additional details concerning common names applied to Xylopia quintasii there: “Kpa-hinei (Mende), the male Kpa tree. The Kpa (definite Kpei) is Tylostemon mannii. Forestry officers have usually given Kpaini as the Mende name for Xylopia quintasii, but I believe my spelling is more correct.” Savill and Fox (1967) gave both the spellings “kpa-hinei” and “kpainii” and added that the same common name is also applied to Xylopia acutiflora.

Representative specimens

GUINEA. Macenta+Beyla Prefectures, Simandou Range, S of Pic de Fon, 8°28'51"N, 8°54'29"W, 765 m, 15 Sep 2008 (yg fr), van der Burgt 1305 (K). SIERRA LEONE. Kabala, Mt. Loma, Kondembaya, 4 Feb 1966 (st), Adam 23553 (MO); Kabala, Mt. Loma, Mousouia, 4 Feb 1966 (fl), Adam 23647 (MO); Railway Hill, 12 Mar 1918 (fl), Aylmer 202 (K); Freetown, 20 March 1914 (fl), Dalziel 956 (K); Njala, 12 Feb 1946 (fl), Deighton 4153 (K); forêt sommet P?eraukouko (Loma), 800 m, 9 Feb 1966 (fl), Jaeger 9283 (K); Trigpoint III Kesewe, 8 Apr 1913 (fl), Lane-Poole 123 (communicated by M. Bañi?) (K); Northern Region, Tankolili District, Sula Mountains South, E of village Farangbaya near Bumbuna, forest patch on higher slopes of Simbili, 8°58'30"N, 11°41'21"W, 820 m, 26 Feb 2010 (fl), Sesay 30 (K); without definite locality, Smeathman s. n. (BM). LIBERIA. Near Firestone Plantations along Dukwia ["Dukwai"] R., 23 Feb 1929 (fl), Cooper 222 (A, BM, F, GH, K, NY, US, YF), Dukwia ["Dukwai"] River, Monrovia, 1929 (st), Cooper 337 (A, BM, F, GH, K, NY, PH, US, YF), 1929 (st), Cooper 372 (A, BM, F, GH, K, MICH, NY, PH, US, YF), 24 May 1929 (yg fr), Cooper 464 (A, BM, F, GH, K, NY, PH, US, YF); National Forest 18 mi N of Tapeta, Voorhoeve 144a (WAG); Nimba Mts., Voorhoeve 910 (WAG). IVORY COAST. Région d’Anyama, forêt du Téké, Aké Assi s. n. (MO); le Banco, Jun 1932 (fr), Aubréville 1345 (MO); Without definite locality [boqueteaux des savanes de Bingerville (Aubréville 1959)], s. d. (fr), Aubréville 1943 (A, P), s. d. (fr), Aubréville1945 (A); Duékoué—Buyo, 4 km E de Pinhou, 26 Mar 1969 (fl), Bamps 2260 (K); Bouroukrou, 20 Dec 1906–20 Jan 1907 (fl), Chevalier 16118 (bois) (K, MO–-3 sheets, P); Dakpadou-Sago, 5°06'N, 5°58'W, 29 Mar 1968 (fl), Geerling & Bokdam 2314 (K, MO, WAG); San Pedro, Nero River near Grand Berybery, 4°40'N, 6°53'W, 5 m, 14 Dec 1997 (fl), Jongkind et al. 4218 (OWU); Abidjan, Banco Forest Reserve, c. 5°25'N, 4°03'W, 22 Dec 1972 (fl), de Koning 985 (OWU); Abidjan, Banco Forest Reserve, Route Martineau, 5°23'N, 4°03'W, 28 Dec 1974 (fr), de Koning 4009 (OWU); forêt de l’Abouabou, between Abidjan and Grand Bassam, 8 Jan 1959 (fl), Leeuwenberg 2406 (K, MO, P, WAG); Banco, s. d. (yg fr), Service forestier 458 (NY, P). GHANA. Tanosu, W. frontier, 18 Sep 1912 (fr), Brent 389 (K—2 sheets); Prov. Western, Enchi Dist., Tano Anwia F. R., Jan 1952 (fl), Andoh 5610 (BM); Fure Forest Reserve near Prestea, 15 Dec 1971 (fl), Deaw Sp 463 (MO, NY, RSA); Eastern Region, District Oda, Kade (University College Farm), 20 Jan 1958 (fl), Enti FH 6881 (K); Sikamang nr. Obuasi, 6 Mar 1975 (fl), Hall & Abbiw GC45145 (MO); Eastern, Atewa Range Forest Reserve, along the Old Geological Survey road, 06°14'06"N, 0°33'0"W, 19 Oct 1994 (fr), Jongkind et al. 1783 (MO); Eastern, Kade Agricultural Research Station, 11 km N of Kade, 6°08'28"N, 00°53'56"W, 200 m, 2 Dec 1996 (fl), Schmidt et al. 2267 (MO); Adeambra, 4 May 1923 (fl, yg fr), Vigne 856 (K). NIGERIA. Benin Province, Iyekuselu District, 8 Dec 1961 (fl), Daramola FHI 45673 (K); Ogun, Ijebu East, Omo forest reserve, 30 Aug 1994 (st), Daramola 434 (F, MO); Cross River State, 25 km N of Oban on road to Ekang, near Cameroun border, 28 Jun 1981 (fr), Gentry & Pilz 32875 (K, MO, WAG); Southwestern Nigeria, 2 mi S of Etemi fishing village, H. F. by the Omo River, 20 Mar 1946 (fl, fr), Jones & Onochie FHI 17012 (K); Ijebu-Ode Province, Akilla, plantations of Nauclea, etc., 12 Nov 1960 (fl), Keay FHI 37826 (K); S. Nigeria, Sapoba, 1930 (fl), Kennedy 702 (K—4 sheets); Mar 1930 (fr), Kennedy 1319 (K); S. Nigeria, without definite locality, s. d. (fr), Kennedy 1543 (A, BM, MO, US), s. d. (fl), Kennedy 1662 (A, BM, K, PR, US, YF), s. d. (fl), 1987 (A, K); Bendel State, forest about 15 km SW of Ekenwan, 6°01'N, 5°18'E, 28 Mar 1977 (fl, fr), Leeuwenberg 11276 (WAG—2 sheets); Prov. Ondo, Dist. Ondo, 1.5 miles from Ore on Agbabu road, 22 Sep 1965 (buds), Okafor & Latilo 057285 (MO); Prov. Ijebu, Shasha Forest Reserve, 26 Feb 1935 (st), Richards [Ross?] 3159 (BM), 12 Jun 1935 (fl), Richards 3334 (BM, F, MO, NY—2 sheets), 2 Sep 1935 (fr), 3434 (BM, MO—3 sheets, NY); Prov. Ijebu, Shasha Forest Reserve, Akilla, 8 Mar 1935 (fl, yg fr), Ross 68 (BM, MO); S. Nigeria, Oban District, 30 Jan 1912 (fl), Talbot & Talbot 1302 (BM, K, NY). SAO TOME & PRINCIPE. S. Tomé, Angolares, Agoa Gombela, 100 m, Jan 1886 (st), Quintas 1083 (BM). CAMEROON. Bipinde, 20–23 Jun 1918 (fl), Annet 319 (OWU, P); 20 km from Kribi, Lolodorf road, 3°00'N, 10°03'E, 9 Jun 1969 (fr), Bos 4773 (K, M, MO, P, WAG—2 sheets); 27 km SW of Bertoua, near Toungrélo, 5 Jan 1962 (fl), Breteler et al. 2398 (A, FI-T, K, M, P, WAG—2 sheets); Southwest Province, near Ngusi village, N of Nyassosso, 4°53'N, 9°42'E, 26 Apr 1986 (fr), Etuge & Thomas 56 (B, K, MO, NY, WAG); bassin du Mungo, village de Mayouka près de la gare de Mujuka, au km 59 du chemin de fer du Nord dans la forêt de la Dzigo, Jul 1917 (fr), Fleury 33517 [Bois no. 23] (OWU, P–2 sheets); without definite locality, Service forestier du Cameroun (Yaoundé), 1935 (fl), Foury 36 (OWU); sud Cameroun, Hallé 4240 (WAG), 4247 (WAG); South West Province, Ndian Division, Korup National Park, Korup Forest Dynamics Plot, 29 May 1999 (fr), Kenfack 1187 (MO); 26 km au SSW de Koso (village situé à 60 km au SSW de Batouri, 27 Jul 1963 (fr), Letouzey 5510 (K—2 sheets); Piste Sanchou-Bale, 18 km SSW Dschang, 26 Nov 1974 (fl), Letouzey 13327 (K, MO, P. WAG); Bipinde-Ebolowa, Dec 1913 (fl), Mildbraed 7613 (K); südlich des Sanaga zwischen Jaunde und Dengdeng unweit der Vereinigung von Lom (Sanaga) und Djerem, etwa 125 km NO Jaunde, Feb 1914 (st), Mildbraed 8294 (K); Prov. Southwest, mile 12 Mamfe road between Kumba and Baduma, 4°45'N, 9°29'E, 4 Oct 1986 (fl), Nemba & Thomas 293 (GH, MO, P, WAG); without definite locality, SRFK 1913 (P); hill facing the village of N’Kolandom, 2°48'N, 11°10'E, 3 Jan 1975 (fl), de Wilde 7871 (K, M, MO, NY); hill roughly between N’Kolandom and N’Koemvone, 2°48'N, 11°09'E, 9 Jan 1975 (fl), de Wilde 7889 (K, MO, P); ca. 50 km NW of Eséka, W of Yaoundé, on opposite of [sic] the Kelè-river, 23 Nov 1963 (fl), de Wilde & de Wilde-Duyfjes 1320 (K, P, WAG—2 sheets); Bipinde, 1900 (fr), Zenker 2080 (B, BM, K, L, M, MO, P, WU), Oct 1913 (fl), Zenker 2094 [408?] (B, GH, M, MO, P, US, WAG); Bipindihof, Dec 1902 (fl), Zenker 2655 (B, BM [mounted on same sheet with 2663], K, L, M, P—2 sheets, WAG, WU); Bipinde, 1913 (fl), Zenker 4738 (B, BM, K, M, MO, P, PR, US); Mimfia, May 1914 (yg fr), Zenker 2095 [580?] (GH, M, MO, P, U, US, WAG), Jun 1913 (fl), Zenker s. n. [359?] (B, GH, M, MO, P, US); Hermanshof, Beguiberge, Sep 1910 (buds), Zenker 4096 (BM, F, K, L, M, MO, P, PR, WU). CENTRAL AFRICAN REPUBLIC. Région de Mbaïki, Station Centrale de Boukoko, Tisserant 527 (BM, K, P), 19 Jun 1950 (fr), Tisserant 1786 (BM, P). EQUATORIAL GUINEA. [Locality not legible], Tessmann 760 (K). GABON. Estuaire: S of Ekouk, 0°06'S, 10°20'E, 3 Nov 1983 (buds, fr), Louis et al. 350 (K, U, WAG); rivière Ayemé, 0°05'S, 9°55'E, 24 Jan 1991 (fr), Louis 3304 (MO); S of Estuaire du Gabon along Remboué River, 0°00'N, 9°50'E, 23 Oct 1991 (fr), McPherson 15432 (MO, WAG); région de Sibang, Heitz 3 (P); Mission Nyonyie, Plaine Zabor, 4 Jul 1990 (fr), Wilks et al. 2107 (MO).—Moyen-Ogooué: Mabounié, 00°50'00"S, 010°27'00"E, 30 Oct 2012 (buds), Boupoya 807 (MO); environs du lac Zilé, près d’Atsié, sur l’Ogooué circonscription de Lambaréné, 12 Aug 1912 (st), Fleury 26594 (MO, P).—Ngounié: Mabounié, along bank of Ngounié River, 00°48'43"S, 010°30'03"E, 12 Oct 2012 (fl, fr), Stévart et al. 4642 (MO); about 22 km along a track in a northern direction from Doussala, 2°12'S, 10°36'E, 4 Dec 1986 (fl), Wilde et al. 9156 (K, P, WAG).—Nyanga: Doudou Mountains, ca. 35 km SW of Doussala, chantier CEB, 2°32'S, 10°30'E, 27 Aug 1985 (fr), Reitsma & Reitsma 1423 (MO, NY—2 sheets, RSA, WAG).—Ogooué-Ivindo: western border of Lopé-Okanda Reserve, along roads S of SEEF chantier, 0°25'S, 11°30'E, 28 December 1991 (fl), McPherson 15698 (MO, WAG); Lopé-reserve, chantier SOFORGA, 0°30'S, 11°33'E, 24 Jun 1986 (fr), Reitsma & Reitsma 2342 (MO, NY, RSA, U, WAG); Lopé Reserve, 0°15'S, 11°40'E, Aug 1991 (fr), SEGC 444 (MO); Reserve de Lopé-Okanda, 0°25'S, 11°30'E, 8 Dec 1990 (fl), White [series 2] 239 (MO); 25 km NNE de Koumameyong, 0°25'N, 11°55'E, 18 May 1987 (yg fr), Wilks 1536 (GH, MO).—Ogooué-Maritime: Rabi-Kounga, halfway down road to well Rab-71, 1°54'S, 9°50'E, 30 m, 11 Dec 1995 (fl), van Bergen 153 (MO, WAG); Toucan, ca. 01°47'S, 09°53'E, 1 Jun 2002 (buds), Bourobou Bourobou et al. 655 (MO, WAG); Petit Loango, 2°20.65'S, 09°36.82'E, 1 Oct 2002 (fr), Bourobou Bourobou et al. 930 (K, MO, WAG).—Woleu-ntem: Crystal Mountains, Tchimbélé, ca. 0°38'N, 10°23'E, 600 m, 18 Nov 2001 (st), Breteler 15795 (MO); la circonscription du Woleu-Ntem, Acourenzoc, région entre Ogooué et Cameroun, 29 December 1933 (fl), Le Testu 9438 (BM, K, P).—Province unknown: Kouilou inférieur, [reçu le 9 Mar 1925] (fl), Sargos 242 (A, P). DEMOCRATIC REPUBLIC OF THE CONGO. Kongo Central: INEAC Luki Mayumbe (Bas-Congo), s. d. (fr), Hombert 475 (BR); INEAC, Luki, Mayambe, 1957 (fr), Mahieu 206 (WAG).—Sud-Ubangi: Boywaza, galerie de la Lua-Vindu [Lua Vindu is ca. 3°30'N, 19°E], 28 Apr 1955 (fr), Evrard 813 (BR).

Xylopia quintasii bears paddle-shaped obovate to oblanceolate leaves, small blunt flower buds, and a small number of striate torulose 1–5-seeded monocarps. The species is remarkably uniform over its broad distribution, varying little in leaf, flower or fruit morphology. The most notable variations are the larger leaves seen in some sterile specimens, and the occasional longer petals, e.g. in Leeuwenberg 11276 from Nigeria the outer petals are ca. 13 mm and the inner petals ca. 11 mm in length. Significantly, the taxonomic synonyms listed above were never compared to X. quintasii when they were published, but instead to other species: X. striata was contrasted with “X. acutifolia” [X. acutiflora], X. lanepoolei with X. parviflora [X. longipetala], and Polyalthia mayumbensis indirectly compared to other African species then placed in Polyalthia, both of which had unisexual flowers, by the observation “Apparently a species with no unisexual flowers.” Pellegrin (1949) seems to have been the first author to recognize the similarity of these species, placing X. striata, X. lanepoolei, X. congolensis, and X. aurantiiodora as taxonomic synonyms of X. quintasii, while Paiva (1966) first placed Polyalthia mayumbensis as a synonym of the species.

Xylopia quintasii resembles X. aurantiiodora, sharing with it the characteristic features of sect. Ancistropetala, i.e. absence of the staminal cone, fleshy basal margins of the inner petals, and the fimbriate aril surrounding the seed. Xylopia quintasii is typically a tall tree, however, with a straight bole and compact crown with crowded horizontal branches, while X. aurantiiodora is a shrub or small tree, reaching eventually a height of up to 10 m. The two differ in other respects as well: the leaf of X. quintasii is usually oblanceolate to obovate and short-acuminate, while that of X. aurantiiodora is characteristically elliptic and obtuse to rounded at the apex; the inner petals of X. quintasii lack the overhanging tooth present in X. aurantiiodora; the styles in X. quintasii are distinctly shorter than the ovary, while they are subequal in length in X. aurantiiodora; the monocarps of X. quintasii are usually tipped by a blunt curved beak, while those of X. aurantiiodora are distinctly acute; and the seeds of X. quintasii are rounded at the apex while those of X. aurantiiodora are distinctly pointed. The two species also differ in habitat: Xylopia quintasii occurs most frequently in upland forest, while X. aurantiiodora is typically a species of inundated forest. Xylopia quintasii is the more western of the two species, but the two overlap in range in Cameroon, the Central African Republic, the western part of the Democratic Republic of the Congo, and the Cabinda Province of Angola.

Recent fieldwork in Gabon by K. Abernethy and collaborators has revealed that the red or purple color of the leaf flush distinguishes X. quintasii from the similar X. congolensis, the latter with a white leaf flush, growing in the same field site. This color difference is not reliably visible in dried specimens, and is seldom reported on collection labels but has been reported for two collections of X. quintasii from Nigeria (Okafor & Latilo FHI 57285, Ross 68), and two from Gabon (Breteler & Jongkind 10470, Breteler 15795). Other differences between the two species are described under X. congolensis.

Collectors often call attention to the strong fragrance of the flowers–“pungently scented” (Gossweiler 6845), “sweetly fragrant” (Schmidt et al. 2267), “heavy sweet scent” (de Wilde 7889)–but nothing is known of pollinators or pollination in this species. Monkeys of several species have been reported as dispersers of the seeds in both Ivory Coast (Eckardt and Zuberühler 2004, Koné et al. 2008) and Cameroon (Mitani 1999, Poulsen et al. 2001, Wang 2008). In Ivory Coast, the seeds were seen to be spat out by the monkeys (Koné et al. 2008) while in Cameroon they were recovered from gray-cheeked mangabey feces (Poulsen et al. 2001).

Xylopia quintasii is reported to be an important forest species in southern Ghana (Hall and Swaine 1981). Species associated with it in upland forest include Khaya sp., Lophira alata, Swartzia sp., and Terminalia superba, and, in inundated forest, Pandanus candelabrum and Marantochloa purpurea. Savill and Fox (1967) describe it as a lower canopy tree in Heritiera utilis-Cynometra leonensis forest of the Gola Forest, Sierra Leone, and that it can be found in secondary forests of various stages. Tessmann (1913) reported that the wood of the species was used to make handles for weapons and tools by the Fang people in Equatorial Guinea.

Engler and Diels, in the protologue of Xylopia quintasii, cited sheets of the type from both K and COI. We examined the K sheet, which corresponds well to the protologue and is annotated by Engler and have chosen it as the lectotype. A specimen at BM with slightly different information (Angolares, Agoa Gombela, 100 m, Jan 1886, Quintas 1083) may represent an additional isolectotype, as it has the same broader than normal leaves found on the K lectotype. Sprague and Hutchinson (1916), in their description of Xylopia lanepoolei, cited two specimens, Lane-Poole 210 and Dalziel 956, but did not designate one as the type. The sheet of Lane-Poole 210 has slightly better flower material, including a packet containing dissected flower parts, and has been designated as the lectotype.

Xylopia Section Xylopia

Xylopia Section Habzelia Engler & Diels, Monogr. afrik. Pflanzen-Fam. 6: 58. 1901. Type: Xylopia aethiopica (Dunal) A. Richard (lectotype designated in Stull et al. 2017, p. 221).

Type

Xylopia muricata Linnaeus.

Description

Nodes with a branch from a single axillary bud; outer and inner petals linear, similar in length, in African species; inner petal margins curved inward at base but of uniform texture, lacking differentiated fleshy basal margins; anther connectives shieldlike at apex, overhanging the anther thecae; staminal cone present, completely concealing the ovaries, rim even; carpels (11–14) 45–50 in African species, the stigmas connivent, smooth; aril bilobed, fleshy; seed coat smooth, sarcotesta present or absent (absent in African species).

Notes

All species of Xylopia occurring in the Mascarene Islands and in tropical America belong to this section. The section is represented in Africa by a single species, X. aethiopica, in Madagascar by four species, on the Mascarene Islands by three species, and in tropical America by about 60 species. The staminal cone is well-developed in all species of section Xylopia, as is the bilobed fleshy aril.

Xylopia aethiopica (Dunal) A. Richard, Hist. phys. Cuba, Pl. vasc. 53. 1841 [“1845”].

Figs 2, 3D, 4B, 16

Unona aethiopica Dunal, Monogr. Anonac. 113–114. Aug–Nov 1817.

Uvaria aethiopica (Dunal) A. Richard, Fl. Senegamb. Tent. 1: 9. 1831.

Anona aethiopica (Dunal) Steudel, Nomencl. Bot., ed. 2, 2: 737. 1841.

Xylopicrum aethiopicum (Dunal) Kuntze, Revis. gen. pl. 1: 8. 1891. Type. SIERRA LEONE. Without definite locality, s. d., H. Smeathman s. n. (lectotype, designated by Verdcourt (1971b, p. 77): G!, secondary lectotype, designated here: G-DC! [00201441 on 2 sheets]; isolectotypes: BM! [000510763, branch on right-hand side of sheet]], FI-W! [005603]).

Xylopia eminii Engler, Pflanzenw. Ost-Afrikas C: 179. 1895. Type. UGANDA. Western Province, Bugoma, Ins. Ssese [“Sesse”], 15 Dec 1890, F. L. Stuhlmann 1233 (holotype: B! [100153132]).

Xylopia dekeyzeriana De Wildeman, Ann. Mus. Congo, Sér. 5, Bot. 1: 43 + t. 19. 1903. Type. DEMOCRATIC REPUBLIC OF THE CONGO [“Belgian Congo”]. Kongo Central Province, Sanda, 1902, M. L. van Houtte in J. Gillet 2258 (lectotype, here designated: BR!; isolectotypes: BR! [8824257, 8824264]).

Xylopia gilletii De Wildeman, Ann. Mus. Congo, Sér. 5, Bot. 1: 42. 1903. Type. DEMOCRATIC REPUBLIC OF THE CONGO [“Belgian Congo”]. Kongo Central Province, Inkisi-Kisantu [“Kisantu”], 1899, J. Gillet 207 (holotype: BR!).

Description

Tree up to 46 m tall, commonly 15–30 m, d.b.h. 30–58 cm, bole slender, base of trunk with plank buttresses 0.5–3 m high extending 0.9 m from trunk, forming a relatively small dense crown; bark gray with shallow longitudinal fissures. Twigs brown to dark gray, glabrous or sparsely and finely pubescent, the hairs 0.1–0.4 mm long, but soon blackish gray, glabrate. Leaf with larger blades 7.3–16.3 cm long, 2.1–6.6 cm wide, subcoriaceous, slightly discolorous, shiny adaxially and dull and often paler abaxially, lanceolate-ovate to elliptic, occasionally oblong, narrowly elliptic, oblanceolate, or rarely ovate, apex acuminate, the acumen 6–20 mm long and sometimes falcate, rarely obtuse, base cuneate to broadly cuneate and short-decurrent on the petiole, glabrous adaxially, finely appressed-pubescent to glabrate abaxially; midrib raised or plane at the base but becoming plane to impressed toward the leaf apex adaxially, often drying dark red toward the base, raised abaxially, secondary veins indistinctly and irregularly brochidodromous, 9–13 per side, diverging at (35–) 45–60° from the midrib, somewhat arcuate, these and higher-order veins slightly raised on both surfaces, sometimes forming a visible reticulum abaxially; petiole 4–9 mm long, somewhat flattened or shallowly canaliculate, transversely wrinkled, sparsely pubescent to glabrate. Inflorescences axillary or from the axils of fallen leaves, 1–5 (–7)-flowered, pedunculate, appressed-pubescent; peduncle 1.5–2.8 (-4) mm long; pedicels 2–4 per peduncle, 4.5–15 mm long, 0.8–1.4 mm thick; bracts 1–2, typically one to either side of pedicel midpoint, caducous, 1.7–2.4 mm long, 2.5–2.9 mm wide, quadrate, semicircular, or ovate, often splitting down the middle, apex obtuse, rounded, or truncate; buds linear-oblong, rarely oblong, apex obtuse to acute, often curved. Sepals erect to slightly spreading at anthesis, 1/4–2/3-connate, 2.2–4.1 mm long, (3.2–) 4.4–6 mm wide, coriaceous, semicircular to broadly triangular, apex acute to rounded, sparsely pubescent to glabrate abaxially. Petals greenish white to yellow, the inner petals sometimes with a tinge of purple at the base in vivo; outer petals spreading but with the apices incurved at anthesis, (11.6–20.9) 28–64 mm long, 3.8–6 mm wide at base, 2.7–3.7 mm wide at midpoint, coriaceous, linear, apex obtuse, longitudinally concave adaxially up to ca. 5 mm from apex, glabrous at base but otherwise densely puberulent adaxially, appressed-pubescent abaxially; inner petals spreading but with the apices incurved at anthesis, (18.7–19.5) 33–51 mm long, 3.6–5.0 mm wide at base, 0.8–2.0 mm wide at midpoint, coriaceous, linear, apex acute, base with undifferentiated margin, densely puberulent adaxially, the hairs becoming sparser toward base, but then densely pubescent within the basal concavity and glabrous again at very base, puberulent except at base abaxially. Stamens 140–300; fertile stamens 1.2–1.7 mm long, oblong, apex of connective 0.2–0.5 mm high, dome-shaped, bluntly conical, or somewhat flattened, overhanging anther thecae, pubescent to glabrous, anthers 6–10-locellate, filament 0.3–0.5 mm long; outer staminodes 1.4–1.7 mm long, oblong, apex acute to truncate; inner staminodes 1.1–1.5 mm long, narrowly oblong, apex rounded; staminal cone (2.2–2.4) 2.9–4.0 mm in diameter, 1.1–1.5 mm high, completely concealing the ovaries, rim even. Carpels (11–14) 45–50; ovaries 1.4–2 mm long, narrowly oblong, densely pubescent; stigmas connivent, 3.5–4.7 mm long, linear, warty, glabrous to pubescent. Torus concave beneath the ovaries but otherwise flat, 2.6–4.6 mm in diameter. Fruit of up to 36 glabrate monocarps borne on a pedicel 10–18 mm long, 2–6 mm thick, glabrate; torus 7–20 mm in diameter, 4–10 mm high, depressed-globose. Monocarps with a green exterior and a pink to pale red endocarp in vivo, 3.2–8.2 cm long, 0.3–0.8 cm wide and thick, linear-cylindrical to narrowly oblong, weakly torulose, apex formed into a blunt beak 1.5–3.5 mm long, base slightly narrowed or contracted into a discernible stipe (1.5–) 3–8 mm long and 1.7–3.5 mm thick, strongly and obliquely wrinkled, verrucose; pericarp 0.5–0.8 mm thick. Seeds 4–12 per monocarp, in a single row, lying oblique to nearly parallel to long axis, 5.0–6.0 mm long, 3.4–3.7 mm wide, 2.5–3.1 mm thick, ellipsoid, elliptic to nearly circular in cross-section, obliquely truncate at micropylar end, rounded at chalazal end, dark brown to black, smooth, shiny, raphe/antiraphe slightly raised, micropylar scar minute; sarcotesta absent; aril pale yellow to orange in vivo, white to dull yellow when dried, bilobed, the lobes 1.5–1.9 mm long, 1.9–2.8 mm wide, fleshy, smooth.

Figure 16. 

Xylopia aethiopica. A Outer petal, adaxial view B Inner petal, adaxial view C Seed, side view D Seed, view of micropylar end E Flower with petals and most stamens removed to show gynoecium, inner staminodes, staminal cone, two outer staminodes, and sepals F Staminal cone G Fruit. H, I Stamens, abaxial view J Leaves K Flower, side view. A, B, E, H, I from McPherson 15168 (MO) C, D from Wilks WIL 922 (WAG) F, G, K from Wieringa et al. 3031 (WAG), J from Nkongmeneck 399 (P).

Phenology

Phenology varies with geography. From Senegal to Nigeria, specimens with flowers have been collected from March to December and with fruits from all months of the year except September and November. From central Africa, specimens with flowers have been collected in all months of the year except May, and with fruits from every month of the year. From the eastern and southern parts of the range, specimens with flowers have been collected in March, May, and from September to December, and with fruits in March and from June to January.

Distribution

(Fig. 17). Xylopia aethiopica has the widest distribution of any African species of Xylopia, occurring in moist forests from Senegal eastward to southwestern Ethiopia and then south to northern Angola, eastern Zimbabwe, and Mozambique. It also occurs on the Gulf of Guinea islands of Bioko and Principe. Xylopia aethiopica grows in a wide range of habitats, including primary forest, secondary forest, upland forest, inundated forest, and lower montane forest, from near sea level up to 1600 meters.

Figure 17. 

Distribution of Xylopia aethiopica. Bolder lines represent country borders, fainter lines lakes and major rivers.

Local names

Békala (Kelai, Le Testu 2178), luvinda (Gossweiler 9060), dodo (Ivory Coast, Thoiré 85), eru (Yoruba, Forestry Department, Benin City 194), macua (Gossweiler 8972), mgana (Bayaka, Le Testu 1877), msaou (Chilunda, Milne-Redhead 2883), muengeve (Harder et al. 2126), mughâna (Echira, Pounou, Vili ou la legounyé, Le Testu 2178), mwawia (Tanzania, Johnson & Murray 1944), mweya (Kiluba de Kabongo, Schmitz 5764), n’cana (Angola, Gossweiler 7845), n’gani (Dioula, Ambe 186), nkana (Havili, Le Testu 1877, Vile eu Loango, Le Testu 2178), nsagalane (Luganda, Eggeling 1524), ojă,ṅ [name would be approximately rendered ‘oyang”] (Tessmann 1913), oyang (Carvalho 4751), oukalla (Pahouin, Fleury 26582), ogana (Gallois, Fleury 26582), okala (Wilks 922, Pahouin, Le Testu 2178), pedjericou (Fon, Laffitte 92), sange (Angola, Welwitsch 765), sengi (Aka, Carroll 1077), ughâ (oghâ?) (Itsogho, Viya, Le Testu 2178), unien (Benin, Forestry Department, Benin City 194, Johnson and Johnson 1974). Additional names reported in the research literature for this species include hwentea (Ghana, Aburi and Kondonuru Regions, Agbovie et al. 2002) or its variant hwentia (Ghana, Konning et al. 2004, Abbiw 1990; a Twi name meaning “slender nose,” referring to the shape of the fruits, according to Burkill 1985), kimba (Nigeria, Barminas et al. 1999, Abubakar et al. 2007), mchofu (Tanzania, World Agroforestry Centre 2017) and spais tik (Sierra Leone, Cline-Cole 1987). Additional common names for the species in West Africa are catalogued in Burkill (1985).

Representative specimens

SENEGAL. Rufisque, Sangalkam, 29 Jan 1948 (st), Adam 417 (MO, P); Presqu’ile du Cap Vert, Sangalkam, Berhaut 1035 (P); Niayes, Dec 1899 (fl, fr), Chevalier 2545 (K, P); D. Pierre du Yolofs, 1837 (fl), Heudelot 566 (P); Senegambie, 1824–1829, Perrottet 9 (P); without definite locality, Perrot[t]et s. n. (BM); Mboro niaye degradée au bord de la route neuve des Niayes, 9 Mar 1965 (yg fr), Raynal 13562 (K, P). GAMBIA. Without definite locality, Ingram s. n., comm. Whiteley (K-000354675). GUINEA BISSAU. Bissau, Brene, 31 Jan 1945 (yg fr), Explorações Botânicas 1717 (B, K, WAG) [=1709 at B, FI-T, P]; Bissau, Prabis, 22 Feb 1945 (yg fr), Explorações Botânicas 1809 (BR, K, P, WAG); Maolina de Cantankez, 11°13'312N, 15°02'503W, 12 m, 14 Nov 1995 (fl), Malaisse & Claes 14911 (BR); Cacine, 30 Jan 1954, d’Orey 264 (K). GUINEA. Kouria, 22 Sep 1905 (fl), Caille 14771 (P); Kouria, Bourkonkourí, 16 Nov 1905 (fl), Caille 14812 (P); [“Senegambia,”] Rio Nunez, 1828, Heudelot s. n. (K—2 sheets, one with date and flowers ex herb. Hook.); environs de Kindia, 1929–1932 (fl), Jacques-Félix s. n. (P); Nzérékoré, Nimba Mountains, just N of Camp 1 (Mifergui), 7°42.40’ N, 8°23.90'W, 650 m, 1 Dec 2006 (fl, fr), Jongkind et al. 7407 (MO); Nzérékoré, Nimba Mountains, between Mifergui camp and old camp 2, 7°41.93'N, 8°23.76'W, 750 m, 23 Jun 2007 (fl), Jongkind et al. 7818 (MO); Conakry (see Keay 1954–1958) [K sheet says Conokry on one label and Coleah on the other], 21 Oct 1896 (fl), Maclaud 189 (K-000354678, P); Cungha, 11°05'50"N, 15°08'45"W, environs Jembezem, 27 Jan 1975 (fr), Malaisse 14705 (BR); Biudélya, Apr 1903 (fr), Paroisse 7 (P); Franceville, Ile Tristão [near Guinea-Bissau border on coast, 10°55, 14°55], Paroisse 54 (P); Kouroussa, Jan 1903 (st), Pobéguin 849 (P). SIERRA LEONE. Without definite locality, Afzelius s. n. (BM—same sheet as Smeathman specimen); without definite locality, 1854, Daniell s. n. (BM, MO); Mt Loma, 28 Sept 1945, Jaeger 2018 (K); Waterloo, 29 June 1914, Lane-Poole 319 (K); Sierra Leon Boundary Commission, 1891–92, Scott-Elliot s. n. (K). LIBERIA. Yékepa, Grassfield, 22 Feb 1965 (st), Adam 20994 (MO), 23 May 1970 (fl), Adam 25627 (MO); Sanniquellie, 1 Jun 1973 (fl), Adam 27753 (MO); Grand Bassa Co., Fortsville, 3 Mar 1948 (fr), Baldwin 11141 (MO); Bomi Hills, Bos 2344 (K); along Dukwia [“Dukwai”] River (near Firestone Plantations), 1929 (fr), Cooper 174 (A, K, BM, F, GH, NY, US); Grand Bassa, 27 Aug 1898 (fl), Dinklage 2005 (A—2 sheets, B, K, MO); 22 mi N of Buchanan, 19 Feb 1970 (fr), Jansen 1874 (MO); Division 33, Firestone plantations 10 mi S of Kakata, Aug 1970 (fl), Jansen 2184 (MO); Bomi Hills, 8 Oct 1970 (fr), Jansen 2219 (MO); 5 mi N of Bomi Hills, 18 Nov 1970 (fl), Jansen 2281 (MO); near Cavalla River, E of Harper, 20 Jul 1971 (yg fr), Jansen 2433 (MO); Bong Range, 32 km N of Kakata, 200 m, 11 Aug 1962 (fl), Leeuwenberg & Voorhoeve 4924 (B, MO, P); near Fetoma, 2 Oct 1926 (fl), Linder 881 (A); on road Bomi Hills–Yoma, 1 mile after bifurcation to “Smal Bopolu,” 24 Jul 1965 (fl), van Meer 74 (MO); Gola National Forest, Bomi Hills, 15 Oct 1965 (fl), van Meer 184 (MO); ca. 15 km E of Monrovia, between Paynesville and Duport, 22 Mar 1962 (fl, fr), de Wilde & Voorhoeve 3633 (A, K, B, P). IVORY COAST. Soubré, Parc National de Taï, 18 Dec 1975 (fr), Aké Assi 13159 (MO); région de Bassam, Yakassé, 18 May 1982 (buds, old fr), Aké Assi 16073 (B, MO); Tchesso, 12 Oct 1997 (st), Ambe 186 (MO); route Bouaké – Tiébissou, 2 Feb 1932 (yg fr), Aubréville 828 (K, P); Abidjan, Jun 1932 (fl, yg fr), Aubréville 1329 (P); Port-Bouet, Aubréville 1944 (P); Lamto Station, ca. 6°15'N, 5°03'W, 11 Jul 1968 (st), Breteler 5251 (K, MO); embouchure du Cavally à Bliéron, 11–13 Aug 1907 (fl, fr), Chevalier 19912 (MO–-2 sheets, P); Bingerville, Jul 1901 (fl), Jolly 287 (K, P); Baoulé, Oct 1895 (fl), Pobéguin 255 (MO—2 sheets, P); bassin du Haut Sassandra et Bassin du Haut Cavally, Dec 1930 (fr), Portères s. n. (MO); 10 km SE of Dabou, direction lagune, 21 May 1969 (st), Versteegh & den Outer 97 (MO); c. 6 km E. and 5 km inland of Bébéby forest bordering Savane de Néro-Mer, 6 Nov 1963, Oldeman 514 (K); San Pedro, 13 Nov 1900 (fr), Thoiré 85 (P). GHANA. Gold Coast, Princes W. Province, 15 January 1939, Akpabla 797 (K); “Gold Coast,” 20 Dec 1923, G. H. Eady s. n. (K); Ankasa Forest Reserve, Mpataba-Elubo Rd., W Region, Jan 1973 (fr), Enti R.1002 (MO). TOGO. Lzory [?], 1905, Kersting A.181 (A, K). BENIN. Adjara, pres du Marché (cercle de Porto Novo), 17 Jan 1910, Chevalier 22747 (K, MO—2 sheets, P); Mts Atakora [“Atacora”] Pays des So(rn)mbas de 400 m a 600 m alt de Natitingou à Bocorona, 21 Jun 1910 (fl), Chevalier 24177 (K, P); Savi environs de Ouidah, Apr 1937 (fl), Laffitte 92 (P). NIGERIA. Akwa Ibom: without definite locality [Eket, according to Keay 1954–1958], Talbot 3281 (BM).—Cross River: Calabar Province, Uwet Dist., Buden Dunlop Estate, 23 Jun 1959 (yg fr), Binuyo FHI 41375 (P); Southern Nigeria “Consulate Hill. O. Calabar, Mar 1900 (fl), Holland 296 (K); Cross River National Park, Oban Hills, ca. 5 km NNW of Ntebachot, 5°32'2"N, 8°43'8"E, 19 Feb 1995 (st), Schmitt et al. 429 (MO); Oban, S. Nigeria, 1911 (fl, fr), Talbot 226 (BM).—Edo: Ohoghobi, 17 Aug 1908 (fr), Forestry Department, Benin City 194 (K-000354684).—Lagos or Osun: Lagos, Dawodu s. n. (K); Southern, near Modakeke, Lagos (sic) Ado, Foster 116 (K).—Ogun: Ijebu East, near Itele Junction along Shagamu Benin Road, 31 Aug 1994 (st), Daramola 441 (F, MO).—Rivers: Nun River, 1860, Mann s. n. (no other data except name (K-0006233420 in herb. Hook.); Keay (1954–1958) cites Mann 485 from this locality, so possibly the same as: “West tropical Africa,” 1859-63, Mann 485 (GH)).–State unknown: S. Nigeria, Without definite locality [probably Sapoba], Kennedy 2172 (A, BM, F, K, MO, US). CAMEROON. Bitya near the River Ja, Bates 1813 (P); a 27 km route Mbalmayo, subdivision Yaoundé, 3 Oct 1953 (fl), Benoit 61 (SRFK 1719) (P); pres du Campement, forêt de Bidou—subdiv. Kribi, 27 Sep 1955 (fl), Benoit 111 (SRFK 1916); km 48 route Kribi—Ndjabilobi, village Elone, 13 Dec 1958 (bud), Benoit 282 (P); Ebolowa road, 5 km from Kribi, 2°55'N, 9°56'E, 20 Nov 1968 (fr), Bos 3341 (P, WAG—2 sheets); NE of Mt. Elephant, about 20 km SE of Kribi, 2°48'N, 10°02'E, 10 Feb 1970 (fl), Bos 6296 (B, MO, P); about 15 km from Kribi, 1 km S of Ebolowa road, 2°51'N, 10°01'E, 20 Feb 1970 (fl), Bos 6382 (B, M, MO, P, WAG—3 sheets); South Province, Department Ocean, Mvie, about 11 km ENE of village Mvie, 2.55N, 10.39E, 400 m, 20 Jan 1998 (fl, yg fr), van der Burgt 328 (MO); 3°37'33"N, 11°34'49"E, 700 m, Oct (fr), Cheek 11057 (K); Douala route Razel, 1955-6, Elias s. n. (P); Bakolle Bakossi on Kumba-Mamfe road, 5°01'N, 9°40'E, 350 m, 24 May 1986 (fr), Etuge & Thomas 148 (MO); 3°36'06"N, 11°35'49"E,700 m, 16 Oct 2002 (fl), Gosline 423 (K); Dengdeng, Jul 1939 (fl, yg fr), Jacques-Félix 4673 (P), 4679 (P); 60 km S of Edea, S of Mboké, 11 km E of km 58 of road Edea-Kribi, ca. 100 m, 22 Apr 1965 (fl, fr), Leeuwenberg 5504 (K, MO, P, WAG); Piste du massif de Fessimi, 9 Feb 1961 (fl), Letouzey 3433 (K, P—2 sheets); a 15 km au SE de Molobo (village situe à 50 km au S de Batouri), 21 Jul 1963 (yg fr), Letouzey 5456 (P, WAG); Mebemonko (20 km NW d’Oveng), 26 Oct 1966 (fl, fr), Letouzey 8186 (B, P—2 sheets); route Mintom I (70 km N de Djoum) a Alati (100 km SE de Djoum), PK 14, 1 Jan 1973 (fl), Letouzey 11773 (K, P, WAG); Dengdeng ca. 700 m April 1914, Mildbraed 8826 (K); Prov. Littoral, 5 km S of Dibombari, near Bonambwasse Village, 04°09'N, 09°41'E, 0-20 m, 18-20 Feb 1988 (fr), Nemba et al. 812 (MO); Canon du Ntem, 16 km SW de Nyabessan, 30 Nov 1982 (fr), Nkongmeneck 399 (P); Nkalé, 1924-5, Pobéguin s. n. (P); Southwest Province, forest in the Korup National Park, elev. 50 m, 5°03'N, 8°48'E, Feb-Apr 1984 (fr), Thomas 3177 (B, MO, P); 16 km on the newly reconstructed road from Ebolowa to Minkok, and then about 2 km to the left along a forest exploitation track, ca. 650 m, 2°58'N, 11°17'E, 29 Jan 1975 (fl, fr), de Wilde 7931 (B, K, MO, P); station du Cacaoyer de N’Koemvone, 14 km on the road from Ebolowa to Ambam, 2°49'N, 11°08'E, 17 Feb 1975 (fl), de Wilde 7970 (K, MO, P); 17 km S of the Lobé River, along road to Campo, 2°43'N, 9°52'E, 18 Mar 1975 (fl), de Wilde 8085 (BR, MO, P); station du Cacaoyer de N’Koemvone, 14 km along the road from Ebolowa to Ambam, 2°49'N, 11°08'E, 10 Dec 1975 (fr), de Wilde 8707 (BR, MO, P); ca. 50 km NW of Eséka, W of Yaoundé, on opposite of the Kelè-river, 23 Nov 1963 (fl), de Wilde 1322 (B, EA, K, MO, P); Mimfia, Jan 1914 (fl), Zenker 499 (B, GH, M, MO, P, US); Bipinde, 1900 (fl, fr), Zenker 2112 (A, B, BM, G, L, MO, WAG); Bipindi, Oct 1903 (fr), Zenker s. n. (F). CHAD. N’Djamena [“Fort Lamy”], Nov 1919 (fl), Allouette s. n. (L). CENTRAL AFRICAN REPUBLIC. Bai Hoker gorilla study area 25 km E of Bayanga, 02°52'N, 16°29'E, 435 m, 26 Feb 1988 (fl), Carroll 1077 (MO); Chari oriental (Pays de Snoussi) [Dar Kouti, fide Tisserant and Sillans 1953], Bakala, 22 Jan 1903 (st), Chevalier 7331 (P); Seriki près Kembe, (fl), Eaux Forêts et Chasses 1946 (P); Botonnti, Tokoli, 4 Dec 1959 (yg fr), Eaux Forêts et Chasses 1989 (P); Yagounda creek 5 km from Koumbala confluence 600 m, 8°25'N × 21°19'E, Fay 4121 (K); Sangha Economique Prefecture, Ndakan, gorilla study area, 02°21'N, 16°10'E, 350 m, 8 Apr 1988 (fl), Harris & Fay 447 (MO); Sangha Economique Prefecture, Ndakan, gorilla study area, 02°21'N, 16°09'E, 350 m, 12 Apr 1988 (fr), Harris & Fay 479 (MO); Sangha Economique Prefecture, Ndakan, gorilla study area, 02°20'N, 16°10'E, 350 m, 28 Apr 1988 (fr), Harris & Fay 536 (MO); Sangha Economique, Dzanga-Sangha Reserve, Ndakan Gorilla study area, 02°21'N, 16°10'E, 350 m, 16 Sep 1988 (fl), Harris & Fay 1132 (K, MO); Yalinga, 1 Apr 1921 (fr), Le Testu 2613 (BM, MO, P); Yalinga, 27 Mar 1923 (fl), Le Testu 4635 (BM, P); Boukoko, 11 Oct 1947 (fl), Tisserant 337 (BM, OWU, P); Boukoko, 20 Mar 1948 (fr), Tisserant 791 (BM); région de Bambari, Maroubas, 3 Mar 1924 (fl, fr), Tisserant 1436 (BM, P—2 sheets). ETHIOPIA. Rég. de Bonga, Jul 1909 (yg fr), Rousseau s. n. (L). SAO TOME & PRINCIPE. Principe: Ôque Pipi, ca. 1000 ft., 6 Dec 1932 (fl), Exell 490 (BM—2 sheets); forest above Infante D. Henrique, ca. 1000 ft., 19 Dec 1932 (fl, fr), Exell 620 (BM); Principe [“Prince’s Island”], 1861, Mann s. n. (K-000623422 ex herb. Hook); Infante Dom. Henrique [“Ricque”], 1956, Rose 386 (P). EQUATORIAL GUINEA. Bioko: Bata-Bolondo, estrada km 15 e nos arredores da povoacao Macomo, 25 Jun 1991 (fr), Carvalho 4751 (B, MO, NY); Moca to Areha Beach pt168 to pt 169, 3.2355 N, 8.6778 E, Luke 12099 (K).—Río Muni: Spanish Guinea, 1908 und 1909 (fl), Tessmann 913 (K). GABON. Estuaire: Envs. Libreville, Mar 1900 (fl), Chalot 45 (P); env. Libreville, 1–5 May 1917 (fr), Fleury 33530, 33531, 33532 (P); Libreville, Apr 1891 (fl, fr), Klaine 176 (P); Libreville, 26 Jan 1896 (fl), Klaine 310 (P); au platform de forage, Remboué 1, 0°13'S, 10°02'E, 21 Jan 1991 (fl), Louis & Moungazi 3293 (MO); Réserve de Wongua Wongué, 23 Jan 1986 (fl), Louis & Reitsma 2006 (WAG—2 sheets); Libreville, Route d’Idokogo, Reserve forestiere de la Mondah, 28 Oct 1948 (fr), Morel 63 SRF (P); Chantier Rougier-Ocean, Oveng, 0°52'N, 11°10'E, 7 May 1985 (fr), Reitsma et al. 855 (MO, NY, RSA); Okala, N of Libreville, forêt de Mondah, Odeg, 0°37'N, 9°20'E, 4 Aug 1992 (fl, fr), Wilks 2610 (MO).—Haut-Ogooué: Without definite locality, 10 Mar 1930 (fl, fr), Le Testu 7960 (BM—2 sheets, MO); Batéké Plateau, Mpassa River watershed, Projet de Protection des Gorilles, 4 km S on Mpassa River, 02°08'15"S, 014°03'59"E, 6 Dec 2001 (buds), Walters et al. 1079 (OWU); ca. 20 km on the road from Franceville to Lékoni, 450 m, 1°37'S, 13°45'E, 28 Aug 1992 (bud, fr), Wieringa & van de Poll 1506 (MO, WAG—2 sheets).—Moyen-Ogooué: 5–15 km NNW of Ndjolé, 0°05'S, 10°45'E, Missanga, 13 Nov 1991 (fl, fr), Breteler & Jongkind 10458 (W, WAG—2 sheets); sur l’Ogooué, près du lac Zile aux env. de Lambaréné, 10 Aug 1912 (st), Fleury 26582 (MO, P); Petit Bam Bam, 21 Aug 1966 (fr), Hallé & Le Thomas 581 (P); SW of Lambaréné, near Lake Ezanga, 01°00'S, 10°17'E, 15 m, 29 Jan 1991 (fl), McPherson 15168 (MO, P); eastern part of the Presidential Reserve Wonga-Wongué, about 100 km S of Libreville, ca. 130 m, 28 Feb 1983 (fl), de Wilde et al. 804 (MO).—Ngounié: Outembo 4 Nov 1916 (fl), Le Testu 2178 (BM, MO); Waka National Park, along bank of Oténinga, 01°09'08"S, 011°06'36"E, 350 m, 2 May 2005 (fr), Leal et al. 634 (MO); SE of Sindora, right bank of Ngoumié R., 17 km W of Camp Waka, 1°13'S, 10°49'E, 400 m, 22 Sep 1985 (fr), Leeuwenberg & Persoon 13614 (MO, P, WAG), 27 Sep 1985 (fl), Leeuwenberg & Persoon 13701 (K, MO, P); Fougamou, 5 km on forestry road following Bendolo River, 90 m, 1°11.7'S, 10°33.1'E, 2 Nov 1994 (fl, fr), Wieringa et al. 3031 (W, WAG—2 sheets).—Nyanga: Tchibanga, 21 Nov 1914 (fl), Le Testu 1877 (BM, EA, K, P); chantier CEB, ca. 50 km SW of Doussala, 2°36'S, 10°35'E, 28 Aug 1985 (fl, fr), Reitsma & Reitsma 1442 (MO, NY—2 sheets, RSA); about 46 km along the track from Doussala to Igotchi, in SW direction from Doussala, 2°40'S, 10°32'E, ca. 160 m, 29 Nov 1986 (fr), de Wilde et al. 9040 (B, BR, K, MO, WAG—3 sheets).—Ogooué-Ivindo: M’Passa Field Station, near Makokou on Riviere Ivindo, 480 m, 14 Jul 1981 (bud, fr), Gentry 33323 (MO); Ipassa, 10 km S of Makokou, 500 m, 29 Oct 1971 (fl), Hladik 1470 part A & B (P), part C (US); Ijessa route du barage Makokou, 8 Feb 1972 (yg fr), Hladik 1943a (P); Res. Lopé-Okanda, 1 km S of Campement (= 26 km E of Ayem), 0°06'S, 11°30'E, ca. 200 m, 1 Nov 1982 (fl), Leeuwenberg & Louis 12424 (K, MO, P, WAG); Réserve de la Lopé, au sud d’Ayem, chantier SOFORGA, ca. 200 m, 0°25'S, 11°30'E, 5 Mar 1989 (fr), McPherson 13712 (MO); Lopé-reserve chantier SOFORGA, 0°30'S, 11°33'E, 25 Jun 1986 (st), Reitsma & Reitsma 2355 (MO, NY); Ivindo National Park, ca. 2 km W of Langoúe Bai, 0°10'15"S, 12°32'33"E, 5 Dec 2002 (fr), Stone & Niangadouma 3664 (MO); Lopé-Okanda Reserve, 2.6 km E along road from Kazambika to Offoué River, 00°07'12"S, 11°42'57"E, 290 m, 31 Oct 2000 (fl), Walters et al. 465 (MO); Reserve de Lopé-Okanda, 200 m, 00°25'S, 11°30'E, 15 Jul 1990 (fr), White [series 2] 29 (MO); Reserve de Lopé-Okanda, 00°25'S, 11°30'E, 200 m, 2 Oct 1990 (fl, fr), White [series 2] 154 (MO); Lopé Reserve, 0°15'S, 11°40'E, 8/5/91 (yg fr), White LJTW 0471 (MO); forêt des Abeilles, 21 km S du confluent Ogooué-Ivindo, 4 May 1983 (fr), Wilks WIL 922 (WAG—2 sheets).—Ogooué-Lolo: “Deforestage Eurotrag,” about 20 km N of Lastoursville, 0°45'S, 12°43'E, ca. 250 m, 16 Nov 1983 (yg fr), Louis et al. 798 (MO).—Ogooué-Maritime: Toucan, 01°47'665S, 9°53'387E, 1 June 2002 (yg fr), Bourobou Bourobou et al. 654 (K, MO—2 sheets); SE of Port Gentil, about 0°40'S, 8°50'E, 16 Sep 1968 (bud, fr), Breteler & van Raalte 5563 (MO, WAG); Gamba, about 2°46'S, 10°02'E, 21 Sep 1968 (fl, fr), Breteler & van Raalte 5612 (MO, WAG—2 sheets); Cap Lopez, 2 Jul, (fl, fr), Chevalier 4305 (P); Rabi, North of Divangui Road, S 1 52.6, E 9 56.1, 6 Mar 2007 (fr), Choo 764 (MO); near Lake Divangui, 20 m, 1°57'S, 9°59'E, 2 Jan 1994 (fr), Haegens & van der Burgt 233 (WAG); near RamboRabi, NW of Rabi site, 1°53.8'S, 9°50.5'E, 10 Nov 1990 (fr), van Nek 300 (WAG); forest near Checkpoint Est, 1°52'S, 9°58'E, 17 Nov 1990 (fr), van Nek 345 (WAG); Rabi-Kounga, Divangui, ca. 1°57'S, 9°59'E, 25 Dec 1991 (fr), Schoenmaker 306 (WAG); Ogooué, route entre Batanga et la riviére Awagné 0 18 10 S 9 18 40 E, Sosef 1759 (K); Gamba, 7.3 along road from airport to Vera, ca. 2°47'S, 10°06'E, 23 Nov 1994 (fl, fr), de Wilde & de Wilde-Bakhuizen 11172 (WAG—2 sheets); Olendé, 01°19'S, 09°02'E, 29 Dec 1988 (fl), Wilks 1890 (MO, OWU).—Woleu-Ntem: Woleu-Ntem, Mbe National Park, Monts de Cristal, Tchimbele Dam area, 00°37'08"N, 010°24'35"E, 300 m, Apr 2004 (st), SIMAB 020102 (MO); about 22 km NE of Asok, newly constructed road, close to the Mbé River, ca. 600 m, 23 Aug 1978 (fr), Breteler & de Wilde 246 (K, MO); 0.5 km NW of Tchimbélé, 550 m, ca. 0°37'N, 10°23'E, 28 Jan 1990 (fl), Wieringa 485 (WAG).—Province unknown: Kouilou, N’kana, 4 Mar 1920 (fr), Sargos 60 (P), 4 Mar 1920 (bud), Sargos 126 (P), 12 Feb 1924 (fr), Sargos 206 (P), 15 Oct 1929 (fr), Sargos 223 (K, P); in ditione Munda Sibange = Farm, 22 Sep 1880 (fr), Soyaux 131 (K). REPUBLIC OF THE CONGO. Village de Loubofo, forêt sur les bords de la Bouénza depuis les chutes jusqu’au bord de la route à 5 kms du village, 8 Nov 1964 (bud, fr), Bouquet 685 (P); bassin de l’Alima-Likouala, environs de Fort Rousset à 16 km sur la route de Gamboma, 21 Jul 1961 (fl), Descoings 8272 (P); Guéne [Guena = Bilala, 4°26’, 12°15’, NE of Pointe Noire], 1960 (fr), Centre Technique Forestier Tropical CTFT 170 (P); Ouesso, 12 May 1971 (st), Grison FG 87 (P); Kouilou, Bena, 8 Oct 1990 (fr), Lisowski B-7179 (BR); Pool, Réserve de Chasse de Léfini, banks of the Léfini River near its confluence with the Louna River, ca. 20 km upstream from Mbouanbé, 320 m, 3°00'S, 15°28'E, 24 Oct 1991 (fl), Thomas et al. 8746 (MO). DEMOCRATIC REPUBLIC OF THE CONGO. Bas-Uele: Tukpwo, galeire de la Diagbe, 25 Jun 1954 (fr), Gerard 1532 (BR). Digba, Prov. Orientale, Terr. Ango, forêt des Akare entre riviére Bili et Asa, 7 Nov 1963 (fr), Gerard 5574 (WAG—2 sheets), Gerard 5616 (MO, WAG); piste Gwane-Balikwe, Jan 1946 (fr), Germain 737 (FI-T, K, P).—Équateur: Eala, 30 Apr 1928 (fl), Corbisier[-Baland] 806 (A, EA, K, MO, US); Botsima, 1°09'S, 21°57'E, 26 Feb 1991 (buds), Dhetchuvi 756 (BR); Eala, 1936 (fl), Leemans 488 (K, MO, P, US); Boyeka (Eala), 16 Aug 1946 (fl, fr), Léonard 311 (BM, K, MO, P, US); de long d’un bras de la riviere Ruki le “Yali,” près d’Eala, Équateur, 2 Jun 1936 (fl), Louis 2147 (RSA).—Haut-Katanga: environs de Elisabethville, galerie de la Kisanga Dec 1939 (fl), Quarré 6201 (BR).—Katanga: Kamunza, 25°50'E, 07°02'S, fin Sep 1957 (buds), Schmitz 5764 (BR).—Kinshasa: Maluku, Tpiene (Menkao ambouchure Bombo), 21 Oct 1970 (fl), Breyne 934 (MO); Kimuenza, 23 Jun 1959 (st), Pauwels 3411 (BR); au dela de la Nsele terr. Maluku, 26 Jan 1965 (fl), Pauwels 4877 (MO, WAG—2 sheets).—Kongo Central: Leopoldville, Prov. Thysville, Territ. Songa, Devred 885 (K); Kinkasi (Benga), Terr. Popakabaka, 1 Jul 1959 (st), Pauwels 3617 (BR); vers Kingoma, Terr. Popakabaka, 4 Jul 1959 (fr), Pauwels 3760 (BR), 22 Jul 1959 (st), Pauwels 3936 (BR); Luki, 8 Aug 1949 (yg fr), Toussaint 2430 (EA, K, P).—Kwilu: Kiyaka – Kwango, Prov. Katanga, Terr. Kikwit, 7 Sep 1955 (fr), Devred 2585 (WAG—2 sheets).—Mongala: Équateur Prov territ Bumba loc. Vallee de la Loeka, 5 Feb 1958 (fr), Evrard 3436 (K).—Nord-Kivu: Walikale Mt. Mika, 1°26'S, 28°03'E, 850 m, 27 Jun 1957 (fr), Pierlot 1707 (BR).—Sankuru: Katakokombe, Sep 1932 (fr), Lebrun 6117 (K, P).—Sud-Kivu: Bulumbu Terr. Shabunda, 780 m, 9 Apr 1959 (buds), Léonard 3759 (BR); Nzowo, Prov. Kivu, Terr. S[c]habunda, 1180 m, 13 Apr 1959 (fl), Léonard 3837 (MO).—Tshopo: Prov. Orientale, Terr. Tsangi, Yangambi, Jan 1961 (fl), Bolema 374 (P); Prov. Orientale, Terr. Tsangi, Ligasa-Mangala, forêt periodiquement inondeé de la Lukombe, 21 Mar 1957 (fl), Evrard 2262 (WAG); Yangambi, Prov. Orientale, Terr. Tsangi, 23 Jul 1958 (fl), Léonard 980 (BR, EA, MO, WAG); Yangambi, 6 Feb 1936 (fr), Louis 1203 (BM, K); Yangambi, km 8.400 de la route de Ngazi, 17 Nov 1936 (old fl), Louis 2848 (NY); Yangambi, ca. 470 m, 27 Apr 1938 (fr), Louis 9099 (B, BM, K, MO, P, US).—Tshuapa: Botsima, 1°09'S, 21°57'E, 7 Mar 1991 (fr), Dhetchuvi 874 (MO); dist. de la Tshuapa, Sep 95 (fl), Dubois 780 (K, P); cerque de Malela 16 Nov 1945 (fl), Donis 1354 (K).—Province unknown: entre Bubinga et Tarawa, Jan 1931 (fl), Lebrun 1964 (K, MO, P). UGANDA. Entebbe District, 3900 ft., 1904, Dawe 118 (K); Bujeje District, 3600 ft, 1905 (fl, fr), Dawe 229 (K); Masaka District, NW side of Lake Nabugabo, 1140 m, 9 Oct 1953 (fl, fr), Drummond & Hemsley 4714 (B, EA, FI-T, K—2 sheets); Namanve, Mengo, 3700 ft., Jan 1935 (fr), Eggeling 1524 (BR, K—indicates Eggeling 1583 to be a wood collection of this number, but duplicates at EA and NY bear only the number 1583); without definite locality, 1922 (yr fr), Maitland s. n. (K). KENYA. Kwale: Ramisi-Mrima Hill road, ca. 7 km past the crossing of the Ramisi River, ca. 4°32'S, 39°19'E, ca. 40 m, 23 Mar 1974 (fl, fr), Faden & Faden 74/306 (K, MO, WAG); Shimba Hills, Mwele Grid Ref. 3922E0416S, 300 m, 13 Nov 1992 (st), Luke 3378 (EA); Shimba Hills, Buffalo Ridge, Grid Ref 3926E0413S, 280 m, 15 Mar 1991 (fl), Luke & Robertson 2709 (K, MO, US). TANZANIA. About 20–30 km SW of Bukoba, 1300 m, 31 Oct 1992 (fl), Breteler 11626 (WAG). Rubare, Bukoba, Bukoba District, Lake Province, 4000 ft., Jul 1951 (buds, fr), Eggeling 6241 (K); Lindi, SE Tanganyika, Chilangal, 800 m, 16 Dec 1942 (fl), Gillman 1261 (K); Bukoba District, Rubogo Swamp, Sep-Oct 1935 (fl), Gillman 398 (BM, K); Amani, 16 Nov 1928 (fl, fr), Greenway 1006 (K); Mlinga, 2800 ft. alt., 18 Feb 1937 (fl), Greenway 4909 (EA, K); Tanga Region, Muheza District, Amani, Mbomole Hill Trail, 05°02'S, 39°10'E, 900 m, 4 Jun 1996 (st), Johnson et al. 1943A (OWU), 1943B (OWU), 1944 (OWU); Stromgebiet des oberen Ruhudje [tributary of Kilombero by Njombe], Landschaft Massagati nördlich des Flusses, ca. 35°30'E, 700 m, 27 Nov 1931 (fl), Schlieben 1480 (BM, K); Amani, Zimmerman 2630 (A, BM, EA). ANGOLA. At Rio Munze, Buco Zau, 26 Aug 1916 (bud), Gossweiler 6612 (BM); along the river Luali, Buco Zau, Mayumbe, 27 Dec 1916 (fl), Gossweiler 6903 (BM, K—2 sheets); Belize, 10 Mar 1917 (fl), Gossweiler 7032 (BM); banks of the rio Lufo, Maiombe, 22 Feb 1919 (fl), Gossweiler 7845 (BM, K–3 sheets); Sumba, Peco, proximum flumen Zaire, 3 Dec 1924 (fl), Gossweiler 8972 (BM, K, US); Maiombe, Nkanda Mbaku, proximum flumen Luali-Chiloango, 50 m, 22 Jun 1924 (fr), Gossweiler 9060 (BM); Maiombe, Nkanda Mbaku, proximum flumen Luali-Chiloango, 50 m, 25 Apr 1923 (fl), Gossweiler 9073 (BM); Sumba, Peco, July 1926 (fr), Gossweiler 9134 (A, BM, MO, US); Sumba, Peco, proximum flumen Zaire, Jun 1926 (fr), Gossweiler 9138 (BM, US); Dundo, proximum flumen Luachimo, Mar 1949 (st), Gossweiler 14222 [leg. Barros Machado] (BM, P); Mayumbe, Gossweiler s. n. (BM); Hochland von Quela, Nolde 216 (BM); in regno Hungo ad limites boreali-orientales regni Angolae, s. d. (fr), Welwitsch 765 (BM). ZAMBIA. Copperbelt: Chingola, Luano Catchments, 31 Oct 1978 (fl), Bingham 3250 (K); Mufulira, 11 Aug 1954 (fr), Fanshawe 1447 (K).—Northern: Shiwa Ngandu, 5400 ft, 21 Jul 1938 (fl, fr), Greenway 5452 (EA, K); Chinsali District, Shiwa Ng’andu, Mansha River, Chusa Falls, 11°09'19"S, 31°33'04"E, 1470 m, 25 Nov 1993 (fl, fr), Harder et al. 2126 (MO).—Northwestern: Mwinilunga, 7 Sep 1955 (fr), Holmes H.1179 (K); Mwinilunga District, R. Matonchi, 21 Oct 1937 (fl), Milne-Redhead 2883 (A, B, BM, BR, EA, FI-T, K—2 sheets, P). MALAWI. Southern: near Likabula Forest Station, at about 3000 ft, 4 Dec 1957 (fl), Chapman 494 (BM, K); lower slopes Mt. Mulanje, near Manager’s House at Esperanza Estate, 700 m, 18 Nov 1985 (fl, fr), Chapman & Chapman 6829 (MO); half way up the outer slopes of Mt. Mulanje at a cliff foot in a hollow on the mountainside above the Chitakale stream (east branch), in full view of the Boma Path to Lichenya Plateau, 4 Dec 1985 (fl), Chapman & Chapman 6921 (K, MO). MOZAMBIQUE. Cabo Delgado: Cabo Delgado, 11°33'05"S, 39°20'51"E, 796 m, 11 Sep 2009 (st), Lötter & Turpin 1898 (K).—Mozambique: Serra Chinga, entre a Chinga-1 e a Chinga 2-A caminho do Chinga 2 [14°59'37.01"S, 38°33'20.98"E], 28 May (fl), Aguiar Macedo & Macuácua 3291 (DSM).—Niassa: Chomba, entre o cruzamento & Chomba, 20 Sep 1948 (st), Pedro & Pedrogão 5285 (EA).—Ribáuè: encosta da Serra Mepáluè (Ie.), 700 m, 12 Dec 1967 (yg fr), Torre & Correia 16453 (BR, EA, K); serra de Chinga, 1100 m, 12 Dec 1967 (fl), Torre & Correia 16460 (B, WAG).—Sofala: Cheringoma, Dando, serração de Inhansato, de Cardoso & Lopes, 1 Jun 1948 (yg fr), Mendonça 4442 (EA, K, MO, WAG).—Zambezia: Mabu Mountain [16.2825°S, 36.3817°E], (fl, fr), Harris 644 (K). ZIMBABWE. Manicaland: [Melsetter District], 1300 ft, 3 Sep 1964 (fl, fr), Wild et al. 6618 (BR, K); Inyanga District, Eastern Highlands Plantation, Pungwe Valley, 3500 ft, 9 Nov 1960 (fl, fr), Wild 5267 (K, MO).—Province unknown: Near Mozambique border, Müller 564 (K).

Xylopia aethiopica is readily distinguished from all other African Xylopia species by the distinctly connate sepals, the large number (up to 36) of narrow, weakly torulose monocarps, and the bilobed aril of the small seeds. The inflorescences are always pedunculate, with the 2–4 large flowers borne on long pedicels. In dried condition, the subcoriaceous leaves have a distinctive dark red midrib on the adaxial surface and a pale abaxial blade surface. Xylopia aethiopica is sometimes confused with Xylopia rubescens, which also has relatively narrow monocarps. Xylopia rubescens has, however, inner petals much shorter than the outer petals, up to 15 monocarps that are strongly torulose and usually distinctly beaked at the apex, and a distinctive reddish cast on the abaxial leaf surface The aril on the seeds of Xylopia rubescens also has the brushlike appendages characteristic of section Neoxylopia.

Although Xylopia aethiopica shows morphological variability, we could not detect any consistent ecological or geographic pattern to the variation. In the field in northeastern Tanzania, we observed that smaller individuals have relatively large “shade” leaves, and that leaves in the canopy of large trees tend to be smaller and narrower “sun leaves.” Herbarium specimens with such small leaves were occasionally seen, e.g. Leemans 488, Léonard 311, both from the western Democratic Republic of the Congo). There is variability in the number of monocarps per fruit and in the number of seeds per monocarp, but this seems to reflect pollination success, with small fruits being scattered throughout the distribution. A number of specimens from the Congo River basin exhibited relatively small flowers at maturity, with petals only ca. 20 mm long, more flowers per inflorescence, sometimes as many as seven, glabrous or sparsely pubescent foliage and inflorescences, smaller numbers of carpels (11–14), and a smaller staminal cone (2.2–2.4 mm in diameter) in the flower. It is possible that this variant is the plant described as Xylopia gilletii by De Wildeman, but the type specimen of that name is in fruit. A field study of this variant is needed.

Xylopia aethiopica grows in a range of habitats across its distribution, and it is difficult to determine from herbarium label data whether its presence in secondary vegetation, and along riverbanks, is spontaneous or the result of deliberate planting and tending. Only a single collection (Kisantu, cultivé, 7 Sep 1912 (st), Chevalier 28331 (P)) explicitly states that the specimen came from a cultivated plant. Savill and Fox (1967) described X. aethiopica in Sierra Leone as inhabiting a wide variety of forest zones, and explicitly characterized it as a tree of secondary forest, where it often formed pure stands in regenerating forest but was absent from older forests (Savill and Fox 1967). In eastern Africa, the species is largely restricted to mountainous areas where the rainfall is higher than in the surrounding lowlands. In the Usambara Mountains near Amani, we found it growing in sapling, subcanopy, and canopy stages in an area of disturbed forest, at one site occurring with smaller trees of Parinari excelsa at the top of a steep slope along a road.

As discussed in the Ethnobiology section, the ethnobotanical literature attests to the continued wide use of the monocarps across West and Central Africa as a spice and medicine. It has been used since ancient times for these purposes. We have seen herbarium specimens from Nigeria (Lagos, Dawodu s. n. (K)), Cameroon (Messa Market, Yaoundé, 7 Mar 1979, Westphal 10202 (P), and Gabon (without definite locality, 1854, Aubry-Lecomte s. n. (P)) with labels stating that the fruits were obtained from or sold in the market. The label of Dawodu s. n. adds “invariably included in the Agbo pot to give tone and strength to the whole compound.” Van Andel (2015) recently reported that the fruits of the Neotropical species X. discreta in Suriname are used medicinally, in ways similar to those for X. aethiopica, by local people of African descent. The name van Andel reported for the plants in Suriname was “pechereku,” and she observed its similarity to the Fon name “pedjericou” applied to X. aethiopica in Benin.

Xylopia aethiopica has been reported as a food source for animals. Usongo and Amubode (2001) indicated that the young leaves of Xylopia aethiopica made up 22.2% of the diet of red colobus monkeys (Colobus badius preussi) at a field site in Korup National Park in western Cameroon. In Ivory Coast, the arillate seeds are consumed by Diana monkeys, which spit out the seeds (Koné et al. 2008) and, in Cameroon, three species of monkeys eat and defecate the seeds (Poulsen et al. 2001). The seeds are also reported to be taken by two species of hornbills in Cameroon (Wang 2008); Gautier-Hion (1985) and Clark and Poulsen (2001) reported the seeds of X. aethiopica to be bird-dispersed. Seeds of X. aethiopica, with the aril still intact, were recovered by T. Engel from the dung of a genet cat in the Shimba Hills of Kenya.

We follow the conclusion of Brizicky (1962) in accepting the year of publication of the combination Xylopia aethiopica as 1841, rather than the printed date of 1845. A lectotype for Unona aethiopica Dun. was chosen by Verdcourt (1971b), who indicated the lectotype to be at G. In the Prodromus herbarium at G there are three sheets, however, and it is not clear whether the lectotypification was intended to include all of them or just a single sheet, so a secondary lectotypification is explicitly designated here.

Xylopia Section Verdcourtia D. M. Johnson & N. A. Murray, sect. nov.

Type

Xylopia mwasumbii D. M. Johnson.

Diagnosis

Nodes with branches from 2–3 axillary buds; outer and inner petals lanceolate, similar in length; inner petals glabrous, flat at the base and lacking differentiated fleshy basal margins; anther connectives rudimentary at apex, not overhanging the anther thecae, staminal cone rudimentary, surrounding only the bases of the ovaries, rim laciniate; carpels 2–5, the stigmas discrete, thickened and falciform; aril cupular, surrounding only the base of the seed; seed coat smooth, sarcotesta absent. Three species in Tropical Africa and at least two additional species in Madagascar.

Notes

This species group in Xylopia was distinguished on morphological grounds (Johnson et al. 2017) and was well supported as an early-diverging monophyletic subclade within the Stenoxylopia clade in the molecular phylogenetic analysis (Stull et al. 2017). With a more comprehensive study of Xylopia species, we find that this species group is marked by synapomorphies comparable to those used to distinguish other sections in the genus. These include glabrous inner petals, rudimentary anther connective apices, relatively short (0.7–2 mm long) and broad stigmas, and a smooth fleshy white cupular aril (Fig. 4D). Species of this section also share outer petals spreading and inner petals erect at anthesis, stamens reduced in number (65 or fewer), and monocarps, where known, that are laterally compressed.

The section is named in memory of Bernard Verdcourt, expert on African Annonaceae and the first author to draw attention to the species of this section, through his descriptions of Xylopia “species A” and Xylopia “species B” (Verdcourt 1971b).

Xylopia lukei D. M. Johnson & Goyder, Kew Bull. 72:11: 3–7. 2017.

Fig. 18A–F, H

Type

MOZAMBIQUE. Cabo Delgado Province, Nangade–Palma, 180 m, Lat 10°54'S, Long 39°54'E, 15 Dec 2003, Q. Luke et al. 10166 (holotype: EA!; isotypes: K! MO! [5795498]).

Description

Tree or shrub up to 9 m tall. Twigs light gray to light brown, sparsely appressed pubescent, the hairs 0.2–0.3 mm long, eventually reddish brown, glabrate, with bark exfoliating; nodes occasionally with two axillary branches. Leaf with larger blades 8.2–11.9 cm long, 4.1–5.8 cm wide, subcoriaceous, slightly discolorous, broadly elliptic to ovate, occasionally oblong-elliptic, apex acuminate with an acumen 7–14 mm long, base broadly cuneate to rounded and slightly decurrent on petiole, glabrous adaxially, sparsely appressed-pubescent to glabrous abaxially; midrib plane adaxially, raised abaxially, secondary veins irregularly brochidodromous, 8–15 per side, diverging at 45–80° from the midrib, these and higher-order veins slightly raised on both surfaces; petiole 3.5–10 mm long, flattened to shallowly canaliculate, glabrous to sparsely pubescent. Inflorescences axillary or rarely slightly supra-axillary, 1–5-flowered, appressed-pubescent; peduncles 1–2 per axil, 1.3–2.6 mm long; pedicels 1–3 per peduncle, 4.5–6 mm long, 1.0–1.2 mm thick; bracts 1–3, usually 2, evenly spaced on pedicel, persistent or with lowest caducous, 1.6–2.9 mm long, ovate to semicircular, apex acute to rounded; buds oblong-lanceolate to oblong, apex obtuse. Sepals slightly spreading at anthesis, 1/4–1/2-connate, 2.6–4.7 mm long, 2.6–4.2 mm wide, coriaceous, oblong, the free portion somewhat pentagonal, apex short-acuminate to acute, appressed-pubescent abaxially. Petals apricot-colored to brownish yellow in vivo; outer petals wide-spreading at anthesis, 8.8–15.5 mm long, 2.8–4.2 mm wide at base, 2.5–3.3 mm wide at midpoint, coriaceous or slightly fleshy, lanceolate, apex acute to obtuse, densely pubescent along margins and at the apex but glabrous and verrucose toward the base adaxially, densely appressed-pubescent abaxially; inner petals erect at anthesis, 9.8–12.5 mm long, 2–2.7 mm wide at base, 1.3–2.1 mm wide at midpoint, coriaceous or slightly fleshy, lanceolate, apex acute, base with undifferentiated margin, wrinkled, verrucose, glabrous. Stamens ca. 65; fertile stamens 1.6–2.3 mm long, narrowly oblong, apex of connective ca. 0.1 mm long, truncate, not overhanging anther thecae, glabrous, anthers 6–12-locellate, filament 0.7–1.0 mm long; outer staminodes ca. 1.5 mm long, oblong, apex rounded to truncate; inner staminodes 1.0–1.2 mm long, oblong, apex truncate; staminal cone 1.0–1.2 mm in diameter, ca. 0.8 mm high, concealing only the bases of the ovaries, rim laciniate. Carpels 3–4; ovaries 1.8–2.0 mm long, narrowly oblong, pubescent, stigmas loosely appressed, 1.5–2.0 mm long, lanceolate, apex acute, sparsely pubescent to glabrous. Torus flat or a little bumpy, 1.3–1.7 mm in diameter. Fruit and seeds unknown.

Figure 18. 

Xylopia lukei and X. mwasumbii. A–F, H X. lukei A Habit B, C Stamens, abaxial view D Outer petal, adaxial view E Inner petal, adaxial view F Flower, side view H Flower with petals removed, showing carpels G, I–P X. mwasumbii G Fruit I Leaves J Flower, side view K, M Stamens, abaxial view L Gynoecium and surrounding staminal cone N Flower gall O Seed with aril removed, side view P Seed with aril removed, view of micropylar end. A–F, H from Luke et al. 10166 (MO) G from Johnson & Ndangalasi 1899 (OWU) I, J from Johnson 1920 (OWU) K–M from Johnson 1928A (OWU) N from Johnson & Ndangalasi 1948 (OWU) O, P from Johnson & Ndangalasi 1884 (OWU) K–M, O, P were drawn from ethanol-preserved material and so have dimensions slightly greater than those in the description, which is based on dried specimens. Reproduced with the permission of the Board of Trustees, Royal Botanic Gardens Kew.

Phenology

Specimens bearing mature flowers have been gathered in November and December; specimens with flower buds only have been collected in May and September.

Distribution

(Fig. 19). Restricted to southeastern Tanzania and northeastern Mozambique, where it occurs in coastal dry forest on reddish orange sands below 200 m.

Figure 19. 

Distributions of Xylopia lukei, X. mwasumbii, and X. tenuipetala in eastern Africa. Bold lines represent country borders.

Additional specimens examined

TANZANIA. Lindi: Sudi [ca. 10°09'S, 39°58'E], 25 May 1943 (fl buds), Gillman 1465 (EA, K). MOZAMBIQUE. Cabo Delgado: between Pundanhar and turnoff to Hunters Mozambique hunting camp, towards Nangade, 10° 54’ 7"S, 39° 56’ 44"E, 169 m, 7 Sept 2009 (fl buds), Burrows et al. 11390 (BNRH, K); Palma District, patch of forest on the coastal plain between the Cabo Delgado peninsula and Quionga, 10°39'03"S, 40°32'59"E, 16 m, 6 Nov 2009 (fl buds), Clarke 97 (K, LMA); N of Palma, on cut line 11 off main road from Palma to Namoto, Way Point: 082 10˚37'27.3"S, 40˚25'05.7"E, ca. 90 m, 6 Dec 2008 (fl buds), Crawford et al. FC323 (K, LMA, P); Nangade to Pundanhar pt427 10.9091°S, 39.9170°E, 168 m, 12 Nov 2009 (fl), Luke & Luke 13760 (EA, K, LMA, MO, P); Quionga to Nachindundo pt437 10.6010°S, 40.6160°E, 60m, 14 Nov 2009 (fl), Luke & Luke 13794 (EA, K, LMA, P); Palma District, Pundanhar to Nangade road. 10°54'29"S, 39°55'12"E., alt. 177 m, 6 Nov 2009 (fl buds), Müller & Clarke 4159 (K, LMA).

Xylopia lukei is distinctive within section Verdcourtia by virtue of its larger leaf blades, 8.2–11.9 cm long and 4.1–5.8 cm wide, usually distinctly brown-discolored on the abaxial surface, a complex inflorescence consisting of up to five flowers with some pedicels branching from a common peduncle, the pedicels with bracts 2.5–2.9 mm long, and pubescent sepals 3.7–4.7 mm with the free portion of the sepal somewhat pentagonal in shape. In other species of the section, the leaf blades do not exceed 8.7 cm in length and are concolorous, the inflorescences comprise one to two (rarely three) flowers, the bracts of the pedicel only reach 1.4 mm in length and are glabrous, and the sepals do not exceed 2.6 mm in length, are at most sparsely sericeous, and have the free portion broadly triangular in shape.

The coastal dry forests where X. lukei occurs were the subject of a recent floristic analysis by Timberlake et al. (2011), who identified at least 23 other plant species with a similar pattern of endemism. Species mentioned on herbarium labels as associates of X. lukei include Chassalia sp., Erythrococca atrovirens, Pancovia holtzii subsp. holtzii, Pyrostria sp. cf. bibracteata, Rinorea angustifolia subsp. ardisiiflora, Uvaria acuminata, and Warneckea sousae. The forests where the plants occur are currently under threat from road expansion and other land development, and a conservation assessment of Endangered was recently proposed for it (Johnson et al. 2017; Table 1).

Xylopia lukei was informally designated as Xylopia “species A” by Verdcourt (1971b), who did not have adequate material to formally describe it. Additional material now supports Verdcourt’s taxonomy.

Xylopia mwasumbii D. M. Johnson, Novon 9: 55–58. 1999.

Figs 18G, I–P

Type

TANZANIA. Dar-es-Salaam Region, Kisarawe District, Pugu Forest Reserve, along N road 0.5 km E of brick factory, 6°52'S, 39°06'E, 200 m, 16 Feb 1996, D. M. Johnson & H. J. Ndangalasi 1884 (holotype: OWU!; isotypes: DSM! K! MO! [217000]).

Description

Tree up to 9 m tall, d.b.h. up to 10 cm, often with multiple trunks, the principal trunk often arching rather than erect; bark white with gray and orange mottling, mostly smooth but exfoliating in patches. Twigs gray, sparsely appressed-pubescent, the hairs 0.2–0.4 mm long, eventually light gray to gray-brown, glabrate; nodes frequently with two or more axillary branches. Leaf with larger blades 4.6–8.7 cm long, 2.4–4.3 cm wide, subcoriaceous, concolorous but paler abaxially, broadly elliptic to elliptic, occasionally ovate, elliptic-ovate, or obovate-elliptic, apex blunt-acuminate with an acumen 4–8 mm long, occasionally obtuse and emarginate, base broadly cuneate and decurrent on petiole, glabrous adaxially, sparsely sericeous abaxially; midrib plane adaxially, raised and somewhat keeled abaxially, secondary veins weakly brochidodromous, 9–11 per side, diverging at 55–70° from the midrib, these and higher-order veins indistinct but raised adaxially, slightly raised abaxially; petiole 4.5–8 mm long, flattened to canaliculate adaxially, glabrous to sparsely appressed-pubescent. Inflorescences axillary or from the axils of fallen leaves, 1–3-flowered, sparsely pubescent to glabrate; peduncle 1 per axil or absent, 1.9–4 mm long; pedicels 1–2 per peduncle, 2.4–3.5 mm long, 0.8–1.6 mm thick; bracts 2–3, evenly spaced along pedicel, caducous to persistent, 0.8–1.6 mm long, ovate, quadrate, semicircular, or deltate, occasionally tearing down the center as the inflorescence enlarges, apex obtuse; buds ovate-lanceolate to lanceolate, apex obtuse. Sepals slightly spreading at anthesis, 1/4–1/2-connate, 1.4–2.2 mm long, 1.5–2.2 mm wide, coriaceous, elliptic, apex obtuse to acute, sparsely sericeous abaxially. Petals olive-yellow to white in vivo; outer petals spreading at anthesis, 8–10 mm long, 2–3 mm wide at base, 2.3–2.6 mm wide at midpoint, coriaceous to slightly fleshy, linear-lanceolate to narrowly triangular, apex acute, appressed-pubescent adaxially, sericeous abaxially; inner petals erect at anthesis, 5.7–7.5 mm long, 1.8–2.2 mm wide at base, ca. 2.0 mm wide at midpoint, coriaceous to slightly fleshy, lanceolate, apex acute, base with undifferentiated margin, glabrous or with a few hairs. Stamens 40–45; fertile stamens 1.5–1.8 mm long, narrowly oblong, apex of connective obtuse to truncate, not exceeding anther thecae, anthers 6–13-locellate, filament ca. 0.7 mm long; outer staminodes absent; inner staminodes absent, but sometimes innermost stamens only 3–4-locellate; staminal cone 0.8–0.9 mm in diameter, 0.4–0.5 mm high, concealing only the bases of the ovaries, rim laciniate. Carpels 2–4; ovaries 1.5–1.7 mm long, narrowly oblong, sericeous, stigmas slightly separated, 0.7–1.1 mm long, lanceolate-falcate, flattened and longitudinally grooved on inner surface, glabrous. Torus flat, 1.5–1.6 mm in diameter. Fruit of up to 3 sparsely pubescent to glabrate monocarps borne on a pedicel 4.5–6 mm long, 1.1–1.4 mm thick, sparsely pubescent to glabrate, with sepals and sometimes persistent; torus not expanded in fruit, obscured by sepals. Monocarps with yellow-green exterior marked with contrasting green raised venation in vivo, 2–2.7 cm long, ca. 1.1 cm wide, 0.4–0.5 cm thick, oblong, not or only weakly torulose, apex truncate, obliquely mucronate, the beak 1–2 mm long, base contracted into a stipe 5–8.5 mm long, 1.1–1.6 mm thick, with raised veins forming oblique ridges and otherwise slightly wrinkled and finely verrucose; pericarp 0.5–0.6 mm thick. Seeds 2–4 per monocarp, in a single row, lying oblique or perpendicular to long axis, 8.5–9 mm long, 5.5–6 mm wide, ca. 5.4 mm thick, ellipsoid, broadly elliptic in cross section, truncate at micropylar end, rounded at chalazal end, light brown, smooth, shiny, raphe/antiraphe plane, visible as a band encircling the seed, micropylar scar 2.2–2.5 mm long, 2.0–2.5 mm wide, elliptic to circular; sarcotesta absent; aril white in vivo, light brown when dried, cupular, 4–5 mm in diameter, 1.7–2.2 mm high, fleshy, smooth.

Phenology

Specimens with flowers were collected from February to May, and with fruits from February to June. We observed no definable peak of flowering in the field but only a few flowers at anthesis were present at any time on a given tree during the flowering period. Similarly, very few fruits could be found on an individual tree at any one time. Vegetative growth seemed to have been stimulated by the short rains of November and December, with production of flower buds following shortly thereafter.

Distribution

(Fig. 19). Occurs in east-central Tanzania, in dry evergreen forest on small ridgetops and plateaus near the coast, with Scorodophloeus fischeri and Manilkara sulcata being frequent canopy associates; 0–300 m. Understory associates in the Pugu Forest Reserve include Lasiodiscus holtzii, Uvaria pandensis, Uvaria puguensis, and species of Hugonia, Hymenocardia, Landolphia, Ochna, and Suregada.

Local names

Mgwaza, mgwaza dume (Kizaramo), mlambambulu (Kiswahili), nnoga (Kiswahili).

Additional specimens examined

TANZANIA. Pwani: Ruvu South Forest, Kisarawe District, 6°58'S, 38°54'E, 260 m, 30 mi SW of Dar es Salaam, 12 Feb–14 Mar 1991 (fr), Frontier Tanzania 2128 (K); Pande, 20 Jul 1982 (st), Hawthorne 1360 (K), Hawthorne 1714 (K); Pande, W. edge, 19 Aug 1982 (buds), Hawthorne 1469 (K); Kisiju, by the sea, Hawthorne 1790 (DSM); Kisarawe District, Pugu Forest Reserve, ridges along north road between Pugu railway station and brick works, 6°52'30"S, 39°06'E, 29 Feb 1996 (fl, fr), Johnson & Mwasumbi 1899 (DSM, OWU); Kisarawe District, Pugu Forest Reserve, along N road 0.5 km E of brick factory, 6°52'S, 39°06'E, 2 Apr 1996 (fl, fr), Johnson 1920 (DSM, OWU), 24 Apr 1996 (fl), Johnson 1928A (OWU, spirit collection only); Kisarawe District, Pugu Forest Reserve, ridgetop over road tunnel, 6°52'30"S, 39°05'30"E, 6 May 1996 (fl), Johnson & Mwasumbi 1936 (DSM, OWU); Kisarawe District, Pugu Forest Reserve, S of Dar–Kisarawe road, ridgetop near Mwakanga railway station, 6°55'S, 39°06'E, 22 Jun 1996 (fl, fr), Johnson & Ndangalasi 1948 (DSM, OWU); Bagamoyo District, Zaraninge Forest Reserve, 54 km E of Hwy, 6°04–13'S, 38°35–42'E, 28 Jun 1996 (buds), Johnson & Mbago 1963 (DSM, OWU); Kisarawe District, Pugu Forest Reserve, bus roundabout area ca. 4 km E of Kisarawe, 06°53'30"S, 39°06'E, 29 Jun 1996 (fr), Johnson 1964B (DSM, OWU); Kisarawe District, Kazimzumbwi Ruvu South [sic], Magogo 618 (NHT, TFD); T6, Ruvu South Forest Reserve, Ufang’ombe area, 06°56'S, 38°49'E, 180 m, 30 Apr 2001 (st), Mwangoka & Saidi 2099 (MO); Kisarawe District: Banda Forest Reserve near Mfyoza village, 12 Nov 1969 (buds), Ruffo 301 (EA, K, NHT, TFD); Pande, Rulangaranga et al. 53 (K, MO); Kisarawe District, Pugu Forest Reserve, 10 Mar 1964 (buds), Semsei 3704 (EA, K, TFD); Kisarawe District, Banda Forest Reserve, 12 Nov 1969 (buds), Shabani 471 (EA, K, TFD); Pande Forest Reserve, 25 km WNW of Dar [es Salaam], 8 Feb 1975 (fl), Wingfield 3311 (DSM, EA, K).

An inconspicuous plant, Xylopia mwasumbii, was first recognized as Xylopia “species B” by Verdcourt (1971b). It is most similar to X. tenuipetala from northeastern Mozambique, but the leaf blades are usually elliptic to broadly elliptic, with cuneate bases and blunt-acuminate to obtuse apices, the pedicels and petals are shorter, and the ovaries are pubescent. These two species have some of the lowest stamen numbers, 50 or fewer, of any African species.

For X. mwasumbii, we calculated an EOO of 3,702 km2 and an AOO of 60 km2; there are only four other African species with a smaller global distribution. It was categorized as Endangered in the IUCN Red List, version 3.1 (IUCN Species Survival Commission 2012), with a conservation assessment of B1ab(iii), Decreasing. The dry evergreen coastal forests where Xylopia mwasumbii grows are still poorly known and very limited in extent. Within this rare forest formation, however, the species may be more common than is currently recognized: its green-tinted flowers and fruits are inconspicuous, and its principal flowering and fruiting occur largely during the long wet season. Xylopia mwasumbii also has a strong resemblance to species of Diospyros and, in herbarium material, to other genera of Annonaceae such as Sphaerocoryne and Toussaintia and may thus be misidentified in collections. The flower-galls, described by Verdcourt (1971b), seem to be a frequent feature of the species, and may be useful for field identification.

Xylopia tenuipetala D.M. Johnson & Goyder, Kew Bull. 72:11: 3, 5, 7–8. 2017.

Figs 3B, 4D, 20

Type

MOZAMBIQUE. Cabo Delgado Province, ca. 1 km W of Quiterajo airstrip on track towards Namacubi Forest, Waypoint JT 627, 11°45'58.9"S, 40°23'59.8"E, 88 m, 21 Nov 2009, D. J. Goyder et al. 6090 (holotype K!; isotypes LMA, LMU, P).

Description

Shrub or tree up to 8 m tall; bark gray, smooth. Twigs green to brownish gray, glabrous, with epidermis soon exfoliating; nodes occasionally with two or more axillary branches. Leaf with larger blades 4.6–5.7 cm long, 2.3–2.7 cm wide, chartaceous to subcoriaceous, concolorous, lanceolate to ovate, apex gradually acuminate with an acumen 4 –11 mm long, base broadly cuneate to rounded, glabrous on both surfaces; midrib plane adaxially, raised abaxially, secondary veins weakly brochidodromous; 9–12 per side, diverging at 60–70° from the midrib, these and higher-order veins slightly raised on both surfaces; petiole 3.5–5 mm long, nearly terete to shallowly canaliculate adaxially, glabrous. Inflorescences axillary, rarely pseudoterminal from abortion of the terminal bud, 1-flowered, glabrous; peduncle rudimentary; pedicels 6.7–7.2 mm long; bracts 2, persistent, the lower one proximal to the pedicel midpoint, 0.7 – 0.8 mm long, ovate, the upper one distal to the pedicel midpoint, 0.9–1.4 mm long, broadly ovate; buds lanceolate, apex acute. Sepals slightly spreading at anthesis, 3/5-connate, 1.7–2.6 mm long, 2.1–2.5 mm wide, chartaceous, broadly ovate, apex acute, glabrous abaxially. Petals yellow-green in vivo; outer petals spreading at anthesis, 13–16 mm long, 2.9–3.4 mm wide at base, 1.6–1.9 mm wide at midpoint, membranous with venation evident, lanceolate, flat, shallowly concave adaxially, apex acute, sparsely pubescent in the center, becoming more densely pubescent toward margins adaxially, appressed-pubescent abaxially; inner petals erect at anthesis, 9.0–10.5 mm long, 1.8–2.1 mm wide at base, 1.2–1.7 mm wide at midpoint, membranous with venation evident, linear-lanceolate, apex acute, base with undifferentiated margin, glabrous. Stamens ca. 50; fertile stamens 1.2–1.5 mm long, narrowly oblong, apex of connective minute, truncate, not exceeding anther thecae, glabrous, anthers 8–10-locellate, filament 0.5–0.7 mm long; outer staminodes absent; inner staminodes 1–1.1 mm long, oblong, apex truncate; staminal cone ca. 0.8 mm in diameter, ca. 0.6 mm high, concealing only the bases of the ovaries, rim laciniate. Carpels 2–5; ovaries 1.1–1.5 mm long, narrowly oblong, glabrous; stigmas loosely appressed, 1.1–1.2 mm long, lanceolate-falcate, apex acute, glabrous; Torus flat, ca. 1 mm in diameter. Fruit of up to 2 glabrous monocarps borne on a pedicel ca. 6.3 mm long, ca. 1.3 mm thick, glabrous; torus 2.8 mm in diameter, 1.5 mm high, globose. Monocarps green with a red endocarp in vivo, ca. 1.8 cm long, ca. 0.9 cm wide, ca. 0.5 cm thick, oblong, flattened-ellipsoid in cross section, apex truncate and obliquely mucronate (1.5 mm), base contracted into a stipe ca. 4 mm long, 1.4 mm thick, finely verrucose; pericarp ca. 0.3 mm thick. Seeds 4–5 per monocarp, in a single row, lying perpendicular to long axis, 7.1–7.9 mm long, 4.4–4.7 mm wide, 3.3–3.7 mm thick, oblong-ellipsoid, elliptic to oblong in cross section, obliquely truncate at micropylar end, rounded at chalazal end, blue-gray to black, smooth, shiny, raphe/antiraphe not evident, micropylar scar 1.2–1.5 mm in diameter, circular; sarcotesta absent; aril white in vivo, amber-colored when dried, cupular, 3.9–4.4 mm in diameter, 2.0–2.4 mm high, fleshy, smooth.

Phenology

Specimens with flowers have been collected in November, the one specimen with fruit was collected in December.

Distribution

(Fig. 19). Endemic to northeastern Mozambique, where it occurs in coastal dry sand forest at elevations of 65–134 m.

Additional specimens examined

MOZAMBIQUE. Cabo Delgado: Namacubi Forest (the Banana), W of Quiterajo, 11°45'55"S, 40°23'45"E, 25 Nov 2008 (st), Burrows & Burrows 10746 (BNRH, K); Quiterajo, within Namacubi Forest, W of Quiterajo, 11°45'47.0"S, 40°21'14.8"E, 29 Nov 2008 (fl), Crawford et al. FC265 (K—2 sheets); Palma area 1 km E of Muangaza, S of Palma, 10°55'24.5"S, 40°23'34.8"E, 65 m, 5 Dec 2008 (fr), Goyder et al. 5089 (K); Quitarajo Pt 463, 11.7676S, 40.3743E, 24 Nov 2009 (fl), Luke & Luke 13884 (EA, K, LMA, P); Macomia District, Quiterajo, Namparamnera forest, 11°49'03.8"S, 40°20'33.1"E, 29 Nov 2008 (fl), Timberlake et al. 5570 (K-738101).

This poorly known species resembles Xylopia mwasumbii, which occurs to the north of its range in central Tanzania, but in X. tenuipetala the leaf blades are lanceolate to ovate, broadly cuneate to rounded at the base and acuminate at the apex, the pedicels and petals are longer, and the ovaries are glabrous. The petals of X. tenuipetala are unusual in the genus—thin, membranous, and translucent rather than coriaceous or fleshy. It occurs in the same area of high plant endemism as X. lukei (Timberlake et al. 2011). A conservation assessment of Endangered was assigned to it in Johnson et al. (2017; Table 1).

Xylopia Section Stenoxylopia Engler & Diels, Monogr. afrik. Pflanzen-Fam. 6: 59. 1901.

Type

Xylopia odoratissima Welwitsch ex Oliver (lectotype, designated in Stull et al. 2017, p. 221).

Description

Nodes with branches from 2–3 axillary buds; outer petals lanceolate to linear, rarely ovate; inner petals lanceolate to linear, rarely ovate, fleshy basal margins absent or present; anther connectives shieldlike at apex, overhanging the anther thecae; staminal cone rudimentary to well-developed, partially to completely concealing the ovaries, rim even to irregularly laciniate; carpels 3–20, the stigmas connivent, smooth; arils absent; seed coat smooth, rarely slightly papillate, pitted, or wrinkled, sarcotesta present, either orange to red or pale green, blue, or gray.

Notes

Members of this section are separated here into two informal groups, named for an exemplar species in each. The species of the Xylopia odoratissima group (Species 12–25) all have an orange sarcotesta, and the group includes all of the African dryland species. The distribution of this group extends from Mozambique, the southern limit of the genus in Africa, north to Sudan and west to southeastern Cameroon (Fig. 8). The Xylopia acutiflora group (Species 26–45) includes all African species known to have a sarcotesta that is light green, blue, or gray in color, as well as one species with an orange sarcotesta. Members of this group are found from Senegal in West Africa east to South Sudan and south to central Angola and western Tanzania.

The two groups are not given formal taxonomic status in this revision. While the Xylopia acutiflora group was strongly supported as a monophyletic group in our phylogenetic analysis (Stull et al. 2017), the Xylopia odoratissima group was not. The groups are separated here to call attention to biological and ecological differences between them and as an aid to species identification.

Xylopia odoratissima group

Plants of the Xylopia odoratissima group are mostly shrubs and understory trees, with only a few species reaching canopy size. The leaves are thin-textured and often hairy on one or both leaf surfaces. The inflorescences are 1–6-flowered, with each pedicel usually arising from the axil separately but occasionally arising from a common peduncle. The monocarps may be sessile or stipitate, and are usually thin-walled, with the seeds lying in a single row or rarely in two rows in a few species. The endocarp, visible in the dehiscent fruit, may be either pink or green. Seeds of all species have a thin sarcotesta that is orange to red and oily or greasy to the touch, but lack arils.

In Africa, the X. odoratissima group has a predominantly Zambezian distribution (Fig. 8). Three subgroups may be distinguished. Xylopia gracilipes, X. holtzii, X. nilotica, X. odoratissima, X. shirensis, and X. torrei share petals of both whorls that are laxly spreading or rarely recurved at anthesis and monocarps with a green endocarp. In the X. arenaria subgroup, consisting of X. arenaria, X. collina, X. keniensis, and X. tomentosa, the outer petals are erect at anthesis, with the inner petal apices emerging at right angles between the outer petals. The fruit endocarp is pink. In the X. gilbertii group, which includes X. flamignii, X. gilbertii, and X. toussaintii, the petals of both whorls are relatively broad and only weakly separating at anthesis and the inner petals bear circular glands at the base. The endocarp color in this group is unknown. Isolated within the group but included because of its overall floral morphology and sarcotesta color is X. wilwerthii from the lower Congo River Basin.

Xylopia arenaria Engler, Bot. Jahrb. Syst. 34: 159. 1904.

Figs 3H, 21B, D, E, G

Type

TANZANIA [“Sansibarküstengebiet”]. Dar-es-Salaam Region, Dar-es-Salam, in parkartigem Buschgehölz des Sachsenwaldes auf Sandboden, Nov 1902, A. Engler 2173 (lectotype, here designated: B! [10 01153133]).

Description

Shrub or small tree up to 6 m tall, secondary branches drooping; bark gray, sometimes blotched with white, smooth. Twigs reddish brown to light gray, pubescent, the hairs 0.2–0.8 mm long, bark soon peeling and flaking in reddish brown strips, becoming glabrate; nodes occasionally with two axillary branches. Leaf with larger blades 3.4–7 cm long, 1.5–2.5 cm wide, chartaceous to subcoriaceous, concolorous to slightly discolorous, ovate to lanceolate-ovate, occasionally lanceolate, apex acute to obtuse, base broadly cuneate, rounded, or subcordate, short-decurrent on petiole, glabrous or with a few hairs on the midrib adaxially, appressed-pubescent abaxially; midrib plane or slightly raised adaxially, raised abaxially, secondary veins indistinctly brochidodromous, 7–12 per side, diverging at 50–70° from the midrib, these and higher-order veins plane or slightly raised on both surfaces; petiole 2.5–5 mm long, shallowly canaliculate, pubescent. Inflorescences axillary or from axils of fallen leaves, 1(–2)-flowered, pubescent; pedicels not pedunculate, 1.8–3.5 mm long, 0.7–1.3 mm thick; bracts 3, evenly spaced along pedicel, persistent, 0.5–1.6 mm long, ovate, semicircular, or crescent-shaped, the upper two often bilobed, apex obtuse to acute; buds ovoid-conic, apex obtuse or less frequently acute. Sepals erect to slightly spreading at anthesis, 1/3–1/2-connate, 2.2–2.5 mm long, 2.1–2.7 mm wide, coriaceous, ovate to broadly ovate, apex acute, pubescent abaxially. Petals pale orange-yellow, cream, or white, the inner petals purplish red or rose-colored inside at the base in vivo; outer petals erect at anthesis, 6.6–10.2 mm long, 2.7–3.2 mm wide at base, 1.8–2.0 mm wide at midpoint, coriaceous or a little fleshy, lanceolate, apex acute, densely puberulent except for glabrous basal patch adaxially, densely appressed-pubescent abaxially; inner petals geniculate at anthesis, with the apices bent sharply outward between the outer petals, 4.7–7.2 mm long, 1.8–2.7 mm wide at base, 0.8–1.2 mm wide at midpoint, slightly fleshy, lanceolate-acuminate, apex acute, base with undifferentiated margin but transversely thickened at the widest point adaxially, puberulent except for glabrous base adaxially, puberulent on apex and medial portion of base but otherwise glabrous abaxially. Stamens 70–200; fertile stamens 1.0–1.2 mm long, narrowly oblong, apex of connective purplish red in vivo, 0.1–0.3 mm long, truncate to capitate, overhanging anther thecae, glabrous or minutely papillate, anthers 12–18-locellate, filament 0.2–0.3 mm long; outer staminodes 1.0–1.2 mm long, clavate to oblong, apex acute, obtuse, or truncate; inner staminodes 0.8–0.9 mm long, oblong, apex obtuse, rounded, or truncate; staminal cone 1.4–1.6 mm in diameter, 0.9–1.2 mm high, concealing only the bases of the ovaries, rim laciniate. Carpels 6–11; ovaries ca. 1 mm long, narrowly oblong, sericeous, stigmas connivent, ca. 2.3 mm long, trowel-shaped, bearing a tuft of hairs at the apex. Torus flat, 1.5–1.8 mm in diameter. Fruit of up to 4 glabrate monocarps borne on a pedicel 4.2–5.3 mm long, 1.2–1.6 mm thick, sometimes with bracts persistent, pubescent; torus of fruit 1.9–2.3 mm in diameter, 0.9–1.8 mm high, depressed-globose. Monocarps with light green exterior and scarlet endocarp in vivo, 1.3–2.5 cm long, 0.5–1.2 cm wide, ca. 0.5–0.7 cm thick, oblong, weakly torulose, apex rounded with an oblique blunt beak 1–2 mm long, base contracted into a stipe 3–5 mm long, 1.5–2.1 mm thick, smooth or occasionally somewhat verrucose; pericarp ca. 0.2 mm thick. Seeds 1–3 per monocarp, in a single row, lying oblique to long axis, 9.2–9.8 mm long, 5.3–5.8 mm wide, 4.5–6.3 mm thick, pyriform, narrowed toward micropyle into a cylindrical neck 2.3–2.8 mm long and 2.8–3.6 mm wide, broadly elliptic in cross-section, obliquely truncate at micropylar end, rounded at chalazal end, brown, smooth, shiny, raphe/antiraphe not evident, micropylar scar 1.2–1.6 mm long, 0.8–1.0 mm wide, elliptic; sarcotesta bright orange, fleshy in vivo; aril absent.

Figure 20. 

Xylopia tenuipetala. A Leaf B Habit C Fruit, showing one dehisced and one undehisced monocarp D Seed, view of micropylar end E Seed, side view F Carpel, with ovary dissected to show two ovules G Stamen, abaxial view H Flower I Inner petal, adaxial view J Outer petal, adaxial view. A, F–J from Goyder et al. 6090 (K) B from photograph of same in vivo C–E from Goyder et al. 5089 (K). Reproduced with the permission of the Board of Trustees, Royal Botanic Gardens Kew.

Figure 21. 

Xylopia collina and X. arenaria. A, C, F, H, I, J X. collina. A Monocarp, lateral view C Flower, lateral view F Stem gall H Habit I Bud J Torus with attached ovaries, lateral view B, D, E, G X. arenaria B Fruit D Habit E Flower bud with one outer petal removed, lateral view G Bud. A, F, H from Johnson et al. 1914 (OWU) B from Johnson & Murray 1890 (OWU) C, I, J from Johnson et al. 1913 (OWU) D, E, G from Johnson et al. 1937 (OWU).

Phenology

Specimens with flowers have been collected in February, May to September, November, and December, and with fruits in February, March, June, July, and November.

Distribution

(Fig. 22). Occurs along the East African coast, from central Kenya south to central Tanzania, growing in forests and bushland, sometimes in secondary vegetation and usually on sandy soil, at elevations of 30–500 m.

Local names

Mkabui (Holtz 321), mtuma-mrihi (Girama, Trump 96), mukunambawa (Girama, Langridge 58, Moggridge 389).

Figure 22. 

Distributions of Xylopia arenaria, X. collina, X. tomentosa, and X. keniensis in southern and eastern Africa. Bolder lines represent country borders, fainter lines lakes and major rivers.

Additional specimens examined

KENYA. Kilifi: Sokoke Forest, road to Jilore Forest Station, 3.2 km from turnoff on Kilifi-Malindi Road, Faden 71/696 (EA); Sokoke Forest, ca. 3 km on track S of Gede to Jilore Forest Station, ca. 3°18'S, 39°57'E, Faden & Faden 74/1225 (EA, K, MO, WAG); Sokoke Forest, Gisau 10 (EA, K), Langridge 58 (EA); K7, Mangea Hill summit, 03°15'S, 39°43'E, 500 m, 8 Apr 1987 (st), Luke & Robertson 318 (EA); K7, Mangea Hill, 3942E0316S, 480 m, 18 Feb 1988 (buds), Luke & Robertson 1008 (EA); 20.2 km Gotani to Bamba, 3°37'S, 39°32'E, 21 Nov 1989 (fl), Luke & Robertson 2134 (EA, K); Kilifi, 17 May 1937 (fl), Moggridge 389 (EA, K); Arabuko-Sokoke Forest, N of Sokoke Forest Station, 3°25’-3°30'S, 39°50-39°54'E, 8 Jun 1973 (fl), Musyoki & Hansen 1007 (EA, K); forest 8 mi S of Jilore Forest Station, near road to Mida, 3°12'S, 39°55'E, Perdue & Kibuwa 10046 (EA, FI-T, K); Arabuko Sokoke Forest, 3°17'S, 39°56'E, 26 Dec 1983 (fl), Robertson 3727 (EA, K, MO); 4.5 km from Bamba toward Ganze, 3°33'S, 39°34'E, Robertson & Luke 6063 (EA); Mangea Hill summit, 3°15'S, 39°43'E, Robertson & Brummitt 6752 (K); Jilore-Mida, SW of Malindi, 3°19'S, 39°58'E, 18 Mar 1973 (st), Sangai EA 15703 (EA); Sokoke Forest, Kilifi, Coast Province, 26 Mar 1954 (fr), Trump 96 (EA, K).—Kwale: Mrima Hill, 7 Dec 1975 (fl), Kokwaro 3951 (K); Buda Mafisini F. R., 04°27'S, 39°24'E, 70 m, 23 Feb 1989 (st), Luke & Robertson 1686 (EA, K); Maluganji Forest Reserve (including Kaya Mtae), 04°06'S, 39°27'E, 200-300 m, 14 Nov 1989 (fl), Robertson & Luke 6000 (EA). TANZANIA. Pwani: Pugu Hills Forest Reserve, Kisarawe, 23 Aug 1972 (fl), Harris et al. DSM 2606 (MO); Dar es Salaam airport, 13 Sep 1970 (fl), Harris & Harris 4989 (B, MO); Pugu Hills near Kisarawe, 6°52–53'S, 39°04–06'E, 2 Nov 1970 (st), Harris & Schlieben BJH 5346 (DSM, EA, WAG); Pugu F. R., near Kisarawe, 31 Jul 1971 (fl), Harris et al. 5859 (MO); Kisarawe District, Pugu Hills Forest Reserve, Harris BJH 6771 (DSM), Harris & Siddiqi BJH 6749 (DSM); Pugu Forest Reserve, Hawthorne 1750 (K–2 sheets); Dar es Salaam Station, Sachsenwald, 30 Nov 1901 (fl bud, fr), Holtz 321 (EA); Dar es Salaam, 6 Dec 1901 (fl), Holtz 393 (EA, PRE); Kisarawe District, Pugu Forest Reserve, bus roundabout area ca. 4 km E of Kisarawe, 6°53'30"S, 39°06'E, 27 Feb 1996 (fl, fr), Johnson 1890 (DSM, OWU), 26 May 1996 (fl), Johnson & Murray 1937 (DSM, OWU); Pugu Forest Reserve, 6°54'18"S, 39°04'59"E, 270 m, 20 Aug 2003 (st), Kibure et al. 1019 (MO); Kisarawe District, Pugu Forest Reserve, 23 Aug 1972 (fl), Mabberley & Harris 1516 (K, WAG); Pugu Forest Reserve, E part of forest between Minaki Secondary School and Pugu Kajiungeno, 06°53'39"S, 39°06'00"E, 180 m, 2 Jun 2012 (fl), Mwangoka & Mulungu 7959 (MO); Kisarawe District, Kisarawe Forest Reserve, Paulo 118 (EA, K); Kisarawe District, Mogo Forest Reserve, Aug 1953 (fl), Semsei 51285 (EA).

This narrowly distributed species has distinctive long hairs on the twigs and leaves, ovate to lanceolate leaves that are acute at the apex, and usually solitary flowers with blunt buds. It shares with X. collina, X. keniensis, and X. tomentosa the characteristic of the tips of the inner petals bending sharply outward at anthesis, such that they emerge through the gaps between the erect outer petals. Description of the floral scent is varied, from over-ripe bananas to “smell of ‘Annonaceae’ with overlying smell of cats” (Mabberley & Harris 1516).

A specimen from Tanzania, Abeid et al. 892 (MO), Pwani, Rufiji District, Kichi Hill Forest Reserve, NW of Nawanje village, Miselu/Mkinga Peak, 8°12'55"S, 38°38'55"E, 594 m, 27 Apr 2001 (fl), has peeling twigs and leaves similar in shape to those of X. arenaria, but the flowers were said to be purple, the outer petals are 4 mm wide at the base, and the specimen was taken from a tree 9 m tall growing at an elevation of 600 m. Fieldwork is needed to determine whether this plant is simply an aberrant specimen of X. arenaria or represents a distinct species.

Despite being locally common in the Sokoke Forest area of Kenya and the Pugu Hills of Tanzania, Xylopia arenaria has yet to be collected from any area in between these two localities. The species grows in Brachystegia spiciformis woodland, and in lowland evergreen forests dominated by other ectomycorrhizal caesalpinioid legumes such as species of Afzelia, Cynometra, Julbernardia, Paramacrolobium, Erythrophloeum, and Hymenaea.

Other type material of the name Xylopia arenaria was not located, and the B sheet of Engler 2173, with good correspondence to the protologue, is formally designated here as a lectotype.

Xylopia collina Diels, Notizbl. Bot. Gart. Berlin-Dahlem 13: 271–272. 1936.

Figs 3I, 4E, 21A, C, F, H, I, J

Xylopia latipetala Verdcourt, Kew Bull. 25(1): 12. 1971. Type. TANZANIA. Lindi District: Rondo Plateau, Nahoro in Albizia, Chlorophora woodland, on old termite-hill, 11 Dec 1955 (fl), Milne-Redhead & Taylor 7617 (holotype: K—2 sheets!).

Type

TANZANIA. Lindi Region, 40 km westlich von Lindi, Lutambasee [“Lumbatasee”], 14 Oct 1934, H.-J. E. Schlieben 5470 (lectotype, here designated: B! [10 0153136]; isotypes: B! [100153137, 100153138, 100153139], BM! [000511056], BR! [0000008824783], G! [00190716], HBG [502482, 502483, 502484], K! LISC! [000402], M! [0107918], MA! [385126], MO! [1703951], P! [00363256], PRE! [0397107-0], S! [07-13459], US! [2214646]).

Description

Shrub or small tree up to 4 m tall, d.b.h. up to 4 cm, twigs often somewhat flexuous on new growth. Twigs brown to reddish brown, densely erect-pubescent, the hairs 1–2 mm long, becoming gray-brown, glabrate or with the hairs somewhat persistent, bark developing minute exfoliations on the leafless growth; nodes occasionally with two axillary branches. Leaf with larger blades 4–8.4 cm long, 2.1–4.4 cm wide, chartaceous, concolorous or slightly discolorous, elliptic to ovate, occasionally lanceolate or obovate, apex acute to rounded, base subcordate or rounded, uniformly pubescent with hairs persistent on both surfaces and on the margin, slightly denser on the midrib; midrib plane to slightly raised adaxially, slightly raised abaxially, secondary veins indistinctly brochidodromous, 6–13 per side, diverging at 35–70° from the midrib, these and higher-order veins slightly raised on both surfaces; petiole 2–4 mm long, shallowly canaliculate, pubescent. Inflorescences axillary, 1-flowered, pubescent; pedicels not pedunculate, 1–3 mm long, 0.6–1.5 mm thick; bracts 2, evenly spaced along pedicel, caducous or rarely persistent, 1–2.7 mm long, semicircular or crescent-shaped, apex obtuse; buds lanceolate to ovoid, apex acute. Sepals erect to slightly spreading at anthesis, 1/5–1/2-connate, 2.5–4.1 mm long, 2.5–3 (–4.8) mm wide, coriaceous, ovate, apex acute, pubescent abaxially. Petals dull red to grayish pink in vivo; outer petals erect at anthesis, 9–20.4 mm long, 2.5–8 mm wide, 1.4–3.9 mm wide at midpoint, coriaceous to fleshy, linear-lanceolate to lanceolate, apex acute, densely puberulent on both surfaces except for a glabrous patch at base adaxially; inner petals geniculate at anthesis, with the apices bent sharply outward between the outer petals, 6–15.4 mm long, 2–5.2 mm wide, wide, 0.4–2.3 mm wide at midpoint, coriaceous to fleshy, lanceolate-acuminate, apex acute, base with undifferentiated margin, transversely thickened at the widest point adaxially, bearing a band of corrugated tissue just above the claw, puberulent except for glabrous base adaxially, puberulent on narrow apical portion and medial region of base but otherwise glabrous abaxially. Stamens 120–200; fertile stamens 0.8–1.4 mm long, narrowly oblong to clavate, apex of connective 0.1–0.3 mm long, shieldlike or slightly hemispheric, overhanging the anther thecae, papillate, anthers 10–17-locellate, filament 0.3–0.4 mm long; outer staminodes 1.0–1.3 mm long, clavate, apex truncate, sometimes oblique; inner staminodes 0.8–0.9 mm long, clavate to oblong, apex rounded to truncate; staminal cone 1.7–2.8 mm in diameter, 1.0–1.7 mm high, concealing only the bases of the ovaries, rim laciniate. Carpels 3–7; ovaries ca. 1 mm long, oblong, sericeous, stigmas connivent, ca. 1.3 mm long, lanceolate to trowel-shaped, bearing a tuft of hairs at the apex. Torus flat, 2.5–3.2 mm in diameter. Fruit of up to 6 glabrate monocarps borne on a pedicel 3–7 mm long, 1.2–2 mm thick, pubescent, with sepals persistent; torus 2.5–4 mm in diameter, 2.0–2.2 mm high, globose to depressed-globose. Monocarps with yellowish or glaucous green exterior and scarlet endocarp in vivo, 1.3–3.6 cm long, 0.6–1.3 cm wide, (0.5–) 0.7–1.2 cm thick, oblong, irregularly torulose, apex obtuse to acute, rarely mucronate, contracted into a stipe 3–10 mm long, 1.7–2.2 mm thick, surface pruinose, longitudinally wrinkled and finely verrucose; pericarp ca. 0.5 mm thick. Seeds up to 7 per monocarp, in two irregular rows, lying oblique to long axis, 9.8–12.2 mm long, 5.5–7.4 mm wide, 4.5–7.0 mm thick, pyriform, narrowed into a cylindrical neck 1.6–2.3 mm long and 2.7–3.5 mm wide toward micropyle, irregularly ellipsoid in cross section, obliquely truncate at micropylar end, rounded at chalazal end, brown, smooth, shiny, raphe/antiraphe not evident, micropylar scar 1.4–1.5 mm long, 1.0–1.1 mm wide, elliptic; sarcotesta bright orange, fleshy in vivo; aril absent.

Phenology

Specimens with flowers have been collected in February, March, October, and December, and with fruits in June and from November to March.

Distribution

(Fig. 22). Restricted to southeastern Tanzania and northeastern Mozambique, where it grows in thickets and open woodland on slopes and plateau surfaces, usually on deep white sand and less commonly on loam, often locally common on roadsides and in areas mixed with planted cashew (Anacardium) trees, at elevations of 200–900 m.

Local names

Mutuka (Kimakonde, Busse 2858), nampemedi (Kiswahili, Johnson & Swedi 1914), pempantavala (Kimuera, Schlieben 5470; the same common name was reported by Schlieben as being used for Popowia (now Monanthotaxis) trichantha, see Diels 1936).

Additional specimens examined

TANZANIA. Lindi: Rondo Plateau, Rondo Forest Reserve, below Forest Station, 10°07'S, 39°14'E, 13 Feb 1991 (fl), Bidgood et al. 1535 (DSM, EA, K, NHT), 13 Feb 1991 (fr), Bidgood et al. 1544 (EA, K–2 sheets, MO, NHT); track from Nyengedi to Rondo Plateau, 10°12'S, 39°20'E, 16 Feb 1991 (fl), Bidgood et al. 1600 (DSM, EA, K, NHT); [“Nordwestliches Muera-Plateau, etwa 600 m ü. M., in dichter Buschenklave auf sandigen Boden”, 14 Jun 1903 (fr), ex Diels 1936], Busse 2858 (EA); Mchinjiri, Rondo Plateau, Nov 1951 (buds), Eggeling 6386 (K, TFD); track from Nyengedi (between Masasi and Mnazimoja) to Rondo Plateau, ca. 3 km N of Nyengedi, 10°14'00"S, 39°24'00"E, 7 Mar 1996 (fl, fr), Johnson & Swedi 1906, 8 Mar 1996 (fl, fr), Johnson & Swedi 1910 (DSM, OWU); Lindi District, Nyangamara Forest Reserve, 10°19'S, 39°59'E, 10 Mar 1996 (fl, fr), Johnson & Swedi 1914 (DSM, OWU); Noto Plateau, N of Chitoa Plateau, 09°54'S, 39°24'E, 8 Jul 2008 (buds), Mwangoka et al. 5801 (OWU); Lindi District, Rondo Forest Reserve, 21 Jan 1968 (fr), Shabani 43 (EA, TFD); Lindi Rural District, Mtama Division, Namiupa Ward, Rondo Forest Reserve, NW of Mihima Village, 10°12'19"S, 39°09'21"E, 640 m, 3 Nov 2005 (fr), Simon Laizer et al. 1352 (OWU).—Mtwara: Newala District, Mahuta, 16 Dec 1942 (buds), Gillman 1055 (EA, K); Mnima, 23 Mar 1943 (fr), Gillman 1293 (K); Newala District, road from Mtama to Mkwiti, ca. 2 km N of Mkwiti, 10°03'S, 40°11'E, 10 Mar 1996 (fl, fr), Johnson & Swedi 1913 (DSM, OWU). MOZAMBIQUE. Cabo Delgado: Palma area, on old western road to Quionga, 10.8 km from the roundabout at the white church, 10°40'49"S, 40°26'11"E, 60 m, 12 Mar 2008 (fl buds), Burrows & Burrows 10942 (K); Palma area, 1 km E of Muangaza S of Palma, 10°55'25.5"S, 40°23'34.8"E, 65 m, 5 Dec 2008 (fr), Goyder et al. 5084 (K); Nanhamba, 7 km S of Mocimboa do Rovuma, 11°19'27"S, 39°18'55"E, 573 m, 10 Sep 2009 (fr), Lötter & Turpin 1882 (K); Mueda Plateau, 11°24'S, 39°23'E, 860 m, 12 Dec 2003 (yg fr), Luke et al. 10039 (K, MO); Niassa, Chomba, entre o cruzamento e Chomba, 20 Sep 1948 (st), Pedro & Pedrogão 5279 (EA); Palma District, Miculumo area, 10 km NW of Palma, 10°40'39.9"S, 40°25'08.9"E, 56 m, 6 Dec 2008 (fl), Timberlake et al. 5640 (K).

The red flowers of Xylopia collina are unusual in the genus and, coupled with the shrub habit, the long erect hairs on the twigs and leaves, and the pruinose surface of the dried monocarps, make it a distinctive and easily recognized plant. With the examination of more extensive material, we do not maintain Xylopia latipetala Verdc. as a distinct species. The type specimen, Milne-Redhead and Taylor 7617, does indeed bear flowers with sepals and petals broader than in the type specimen of X. collina, but the gap in sizes presented in Verdcourt’s (1971a) description has now been filled by additional specimens: Bidgood et al. 1535, for example, has flowers with the outer petals 4.9–6.9 mm wide, i.e. intermediate in size between the two described species. We also observed considerable variation in petal size and shape within field populations of X. collina, suggesting that variation in petal size is a normal attribute of this species.

Although the flowers emit an ester/vinegar scent of rotting fruit during the middle of the day, suggesting small flies, nitidulid beetles, or thrips as possible flower visitors, no pollinators were found. Color cues may be important in determining the timing of pollinator behavior, as the flower buds are initially white, then become pink or pinkish orange, and finally turn pinkish red. The tips of the petals often become black or dark gray. A band of corrugated tissue crosses the adaxial surface of the inner petal at its widest extent and may provide a food reward for pollinators. As in X. arenaria, onset of anthesis is signalled by the bending of the apices of the inner petals so that they emerge through the gaps between the erect outer petals.

Associates observed at several sites included Bosqueiopsis gilletii, Milicia excelsa, Grewia conocarpa, and species of Albizia, Heinsia, Hymenocardia, Indigofera, Mimosa, and Pteleopsis. In the area of a recent burn on the Rondo Plateau in March, 1996, Xylopia collina was one of several Annonaceae, including also Dielsiothamnus divaricatus, Monanthotaxis buchananii, Monodora minor, and Uvaria acuminata, observed to be regenerating from a rootstock after fire. The indurated black bud scales on the vegetative buds may play a role in allowing shoot regeneration after fire or drought; such bud scales are unusual in Annonaceae, where dormant shoot tips are typically naked. The growth of X. collina also exhibits distinctive stem galls (Fig. 20F) that are seen in other African species of Xylopia.

There are four sheets of the type collection, Schlieben 5470, at B. None is in exact agreement with the protologue concerning the type locality, but the sheet with detail drawings of the floral parts attached is chosen as the lectotype.

As shown in Table 1, the AOO for this species was relatively high (76 km2) for the size of its EOO (12,374 km2). We found X. collina to be locally frequent along roadsides, which may make it more frequently collected. In the IUCN Red List (version 3.1), it has been classified, however, as Endangered, largely due to the small size of its global distribution and local habitat alteration.

A decoction of the leaves of Xylopia collina was reported by local informants in the Nyangamara region of southern Tanzania to be used as a treatment for hernia.

Xylopia flamignii Boutique, Bull. Jard. Bot. État 21: 110. 1951.

Fig. 23A–E

Xylopia lenombe Paiva, Mem. Soc. Brot. 19: 76 + pl. 12. 1966. Type. ANGOLA. Cabinda Province, Cabinda na Chiaca, 10 Jun 1960, R. Monteiro & F. C. Murta 227 (holotype: LUAI; isotypes: BM! [0005109030], LUA, PRE! [0774857]).

Type

DEMOCRATIC REPUBLIC OF THE CONGO [“Belgian Congo”]. Maï-Ndombe Province, Nioki, May 1941, A. Flamigni 9026 ter (holotype: BR! [0000008824745]; isotypes: BM! [000511044], BR! [0000008824745], K! [000199057], P! [00169149]).

Description

Tree up to 30 m tall. Twigs dark brown to gray brown, eventually light brown or gray, initially appressed-pubescent, the hairs 0.1–0.2 mm long, soon glabrate; nodes occasionally with two axillary branches. Leaf with larger blades 5.2–7.9 cm long, 1.3–2.7 cm wide, chartaceous, discolorous and shiny black adaxially, brown and dull adaxially, lanceolate to lanceolate-oblong, apex attenuate to short-acuminate with an acumen 7–8 mm long, base broadly and obliquely cuneate, glabrous or occasionally with a few hairs on the midrib adaxially, finely appressed-pubescent abaxially; midrib plane adaxially, raised abaxially, secondary veins indistinctly brochidodromous, 13–17 per side, diverging at 45–65° from the midrib, strongly raised adaxially, raised abaxially, higher-order veins strongly raised to form a conspicuous reticulum adaxially, slightly raised abaxially; petiole 3–5 mm long, somewhat flattened, semi-terete to shallowly canaliculate, sparsely pubescent. Inflorescences axillary, 1–2-flowered, sparsely pubescent; pedicels not pedunculate, 2.5–5 mm long, 0.7–1.1 mm thick; bracts 2–3, evenly spaced on pedicel, caducous or uppermost sometimes persistent, 1.4–2 mm long, ovate, sometimes bilobed, apex obtuse to rounded; buds broadly ovoid, apex obtuse to short-acuminate. Sepals spreading at anthesis, connate at base, 1.8–2.7 mm long, 2.7–3.3 mm wide, thickly coriaceous, almost fleshy, broadly ovate to semicircular, apex acute, obtuse, or rounded, sparsely pubescent abaxially. Petals yellowish white or red in vivo; outer petals slightly spreading at anthesis, 5.5–7.3 mm long, 3.5–4.3 mm wide at base, 2.5–2.8 mm wide at midpoint, fleshy, ovate, apex acuminate, densely pubescent on upper half, glabrous in lower half adaxially, sericeous abaxially; inner petals slightly spreading at anthesis, 4.7–6.0 mm long, 3.0–4.0 mm wide at base, 1.9–2.5 mm wide at midpoint, fleshy but thinner than outer petals, rhombic to sagittate, apex acute, base with margin differentiated into two circular corrugated glands 1–1.5 mm in diameter just above and to either side of the claw, the glands and claw glabrous, petal otherwise densely pubescent. Stamens ca. 100; fertile stamens 1.1–1.4 mm long, narrowly oblong-clavate, apex of connective 0.2–0.3 mm long, depressed-globose, overhanging the anther thecae, minutely papillate, anthers 9–11-locellate, filament 0.2–0.3 mm long; outer staminodes 1.2–1.4 mm long, obovate, narrowly oblong, or clavate, apex obtuse, rounded, or obliquely truncate; inner staminodes 1.1–1.3 mm long, oblong, apex obtuse; staminal cone 1.7–1.9 mm in diameter, 0.5–0.8 mm high, concealing only the bases of the ovaries, rim laciniate. Carpels 10–17; ovaries 1.2–1.5 mm long, linear-oblong, pubescent, stigmas loosely connivent, 0.9–1.5 mm long, trowel-shaped, glabrous or with a few orange hairs at apex. Torus flat, 1.7–2.1 mm in diameter. Fruit of up to 22 glabrate monocarps borne on a pedicel ca. 6 mm long, 2.0–2.8 mm thick, glabrate; torus 6–6.7 mm in diameter, ca. 4.5 mm high, depressed-globose. Monocarps with green exterior in vivo, endocarp color unknown, 3.7–4.8 cm long, 0.7–0.8 cm wide, 0.6–0.7 cm thick, narrowly oblong and slightly falciform, torulose, apex rounded or with a oblique blunt beak 1–2 mm long, base gradually contracted into a stipe 7–11 mm long, 1.8–3.2 mm thick, longitudinally wrinkled and striate; pericarp 0.2–0.4 mm thick. Seeds 3–5 per monocarp, in a single row, oblique to long axis, 7–7.6 mm long, 4.3–4.8 mm wide, 3.8–4.1 mm thick, ellipsoid, elliptic in cross-section, obliquely truncate at the micropylar end, rounded and sometimes flattened from the adjacent seed at the chalazal end, light brown, smooth, not shiny, raphe/antiraphe not evident, micropylar scar 1.7–1.8 mm long, 0.8–1.0 mm wide, oblong or elliptic; sarcotesta red in vivo; aril absent.

Figure 23. 

Xylopia flamignii and X. gilbertii. A–E X. flamignii A Flower, side view B Close-up of adaxial leaf surface, showing raised venation C Leaves D Inner petal, adaxial view E Outer petal, adaxial view F–J X. gilbertii F Flower, side view G Inner petal, adaxial view H Outer petal, adaxial view I, J Leaves. A–E from Bradley 1136 (OWU) F–I from Louis 6777 (MO) J from Letouzey 10707 (P).

Phenology

Specimens with flowers have been collected in May, June, October, and December, and with fruits in June (immature) and July.

Distribution

(Fig. 24). Occurs from eastern Gabon to the western Democratic Republic of the Congo and south to the Cabinda Province of Angola. One collection is from upland forest, one from forest edge, one from mature riverine forest/savanna edge, and one from secondary forest; the only reported elevation is 430 m.

Local names

Itomba (Loutumbe, Gilbert 14335), itumba (Cauwe/Service Forestier S.F./66), lucanga lenombe (Monteiro & Murta 227).

Figure 24. 

Distributions of Xylopia gilbertii, X. toussaintii, and X. flamignii. Bolder lines represent country borders, fainter lines lakes and major rivers.

Additional specimens examined

GABON. Haut-Ogooué: ca. 1 km S of Gorilla Research Station, across Mpassa River on savanna-primary riverine forest border, 02°07'15"S, 014°04'40"E, 430 m, 1 Dec 2001 (fl), Bradley et al. 1136 (MO, OWU). REPUBLIC OF THE CONGO. Village Abala, terre Okouésé, Sous-Préfecture de Boundji, 20 Jun 1965 (st), Bouquet 1447 (P); Plateau Batéké, piste km 46 Maluku—Tréchot, forêt de Mandiélé, 12 Oct 1968 (fl), Sita 2737 (P). DEMOCRATIC REPUBLIC OF THE CONGO. Kinshasa: Kimuenza, 23 Jun 1959 (st), Pauwels 3391 (BR).—Maï-Ndombe: Ipeke, Lac Mai-Ndombe [“Lac Léopold II”], Jun 1950 (st), Cauwe/Service Forestier S.F./66 (BR); Lac Mai-Ndombe [“Lac Leo II”], Panza, 3 Jul 1953 (fr, old fl), Gilbert 14335 (BR). ANGOLA. Cabinda, na Reserva da Chiaca, 6 Jun 1960 (st), Monteiro & Murta 181 (PRE).

This species stands out from other African xylopias by the combination of narrow leaves with a pronounced vein reticulum on the adaxial surface, short broad flowers on short pedicels, and the basal margins of the inner petals marked by corrugated circular glands. In the latter character, it resembles X. gilbertii and X. toussaintii, but, unlike those species, the leaves are shiny and glabrous on the adaxial surface rather than dull and pubescent. The plant has a greater resemblance to X. wilwerthii, but differs from that species in the short pedicels, the short and broad petals, and leaves that are attenuate to short-acuminate; X. wilwerthii, in contrast, has pedicels 8.5–21.5 mm long, petals 14–31 mm long, and long-acuminate to caudate leaves.

Only two specimen labels gave notes regarding flower color: one described the petals as yellowish white, the other as red. The label of Bradley et al. 1163 notes a mild cinnamon odor to the flowers.

With an EOO of 108,538 km2 and an AOO of only 32 km2, Xylopia flamignii belongs to the group of species that occupy a relatively wide range but are either undercollected or rare (Table 1). It was given a conservation assessment of Vulnerable (D2) by Onana and Cheek (2011).

The isotype of Xylopia lenombe at BM was received on loan already annotated as Xylopia flamignii, and corresponds well with the type specimen of the latter in its flowers and leaves. This specimen, bearing both flowers and fruits, helped to confirm the identity of specimens of X. flamignii with fruits only.

Xylopia gilbertii Boutique, Bull. Jard. Bot. État 21: 110–111. 1951.

Fig. 23F–J

Xylopia ardua Sillans, Rev. Bot. Appliq. 33: 555–556 + pl. 8. 1953. Type. CENTRAL AFRICAN REPUBLIC [“Oubangi-Chari”]. Boukoko, Dec 1951, C. Tisserant 2329 (lectotype, here designated: P! [00169140]; isotypes: BM! [000510989], P! [00169141, 00169142, 00169143], US! [2679729]).

Type

DEMOCRATIC REPUBLIC OF THE CONGO [“Belgian Congo”]. Tshopo Province, Yangambi, plateau de la Luweo, alt. 470 m, Nov 1937, J. Louis 6777 (holotype: BR!; isotypes: B! [100249561], BM! [000510912, 000511052], BR! [8824738], K! [000542217], MO! [1639391], P! [00169152], US! [2091368]).

Description

Tree up to 40 m tall, d.b.h. up to 40 cm, bole slender, cylindrical, with small buttresses at the base; bark brown or mottled with white, yellow, green, or orange-brown, lightly cracked or longitudinally fissured. Twigs brown, eventually gray and longitudinally wrinkled, persistently erect-pubescent, the hairs orange to rusty and 0.3–0.8 mm long; nodes occasionally with two axillary branches. Leaf with larger blades 4.2–9.7 cm long, 2.0–3.3 cm wide, chartaceous to subcoriaceous, slightly discolorous, elliptic-oblong to lanceolate, occasionally oblong or ovate, apex acute to nearly rounded, base broadly cuneate to rounded, erect-pubescent (densely so on the midrib) to glabrate adaxially, persistently erect-pubescent abaxially; midrib plane adaxially, raised abaxially, secondary veins indistinctly brochidodromous, 7–14 per side, diverging at 45–60° from the midrib, plane to slightly raised adaxially, raised abaxially, higher-order veins indistinct adaxially, slightly raised abaxially; petiole 2.8–4 mm long, semi-terete to shallowly canaliculate, densely pubescent. Inflorescences axillary but often clustered at bases of newly elongating shoots, 1–6-flowered, densely pubescent; peduncle 1 per axil, 1.5-2.5 mm long; pedicels 2–6 per peduncle, 1–2 mm long, 1.3–1.7 mm thick; bracts 2, evenly spaced and somewhat overlapping, caducous or persistent, 2.3–3.5 mm long, ovate to broadly ovate, apex obtuse; buds ovoid, apex obtuse or acuminate to an expanded base. Sepals spreading at anthesis, free or connate just at base, sometimes slightly imbricate at base, 1.6–2.4 mm long, 2.8–4.2 mm wide, coriaceous, reniform to semicircular, apex acute to rounded, densely pubescent abaxially. Petals fawn-olive, brown-violet, or purple in vivo; outer petals slightly spreading at anthesis, 6.6–11 mm long, 2.8–6.4 mm wide at base, 2.4–4.4 mm wide at midpoint, fleshy, lanceolate to ovate, apex obtuse, pubescent on distal half and verrucose on proximal half adaxially, densely appressed-pubescent abaxially; inner petals slightly spreading at anthesis, 5.8–9.3 mm long, 3–4 mm wide, 1.4–3.2 mm wide at midpoint, fleshy, lanceolate, apex obtuse to acuminate, base with margin differentiated into two roughly circular glands 0.6–1.4 mm in diameter, pubescent on distal half and glabrous on concavity/claw adaxially, pubescent abaxially. Stamens 80–130; fertile stamens 1.1–1.3 mm long, oblong-clavate, apex of connective 0.3–0.4 mm long, shieldlike to capitate, overhanging the anther thecae, minutely puberulent to glabrous, anthers 10–13-locellate, filament 0.3–0.4 mm long; outer staminodes 1.1–1.3 mm long, broadly clavate, apex obtuse to obliquely truncate; inner staminodes 0.9–1.0 mm long, narrowly oblong to broadly clavate, apex obtuse to truncate; staminal cone 1.3–1.8 mm in diameter, 0.4–0.6 mm high, concealing only the bases of the ovaries, rim laciniate. Carpels 6–11; ovaries 1–1.5 mm long, oblong, pubescent, stigmas connivent, 1.5–2.2 mm long, linear, sparsely pubescent. Torus flat, 1.6–2.2 mm in diameter. Fruit of up to 10 sparsely pubescent monocarps borne on a pedicel 4.5–10 mm long, 1.5–2.5 mm thick, sparsely pubescent; torus 2.8–3.8 mm in diameter, 2.5–2.6 mm high, discoid. Monocarps reddish or purplish green in vivo, endocarp color unknown, 2.5–3.7 cm long, 1–1.3 cm wide, 0.5–0.8 cm thick, oblong to clavate, sometimes irregularly torulose, apex obtuse to obliquely truncate, sometimes with an offset blunt beak 1–1.5 mm long, base contracted into a stipe 5–13 mm long, 1.2–3.5 mm thick, sometimes with a longitudinal groove abaxially, obliquely wrinkled, sparsely verrucose; pericarp ca. 1 mm thick. Seeds up to 6 per monocarp, in a single row, oblique to long axis, 7.4–10 mm long, 4.2–6.7 mm wide, (3.1–) 3.5–5.4 mm thick, ellipsoid, elliptic in cross-section, truncate at micropylar end, rounded at chalazal end, light brown, smooth, dull or slightly shiny, raphe/antiraphe not evident, micropylar scar 1.3–2.2 mm long, 1.5–2.5 mm wide, elliptic, circular, or transversely elliptic; sarcotesta red in vivo; aril absent.

Phenology

Specimens with flowers have been collected from October to February, and with fruits from February to April, in June, and from October to December.

Distribution

(Fig. 24). Scattered in a narrow band from southern Cameroon and northern Gabon east to the southwestern Central African Republic and the northern Democratic Republic of the Congo; upland forest; 470–900 m. Associates include Coula edulis Baill. and Millettia duchesnei De Wild. Harris (2002) reports the species from the Dzanga-Sangha region of SW Central African Republic, but we have not seen the vouchers.

Local names

Bompaie bo fufow (Turumbu, Louis 6777), molo-mosoma (Lissongo, Tisserant 625, 2329).

Additional specimens examined

CAMEROON. A 9 km à l’ouest de Yenga Port Gentil, village situé à 35 km au NNE de Moloundou, 21 Apr 1971 (fr), Letouzey 10707 (P); près Akonetche, PK 95 sur route Minton I (70 km E de Djoum)-Mbalam (140 km ESE de Djoum), 22 Jan 1973 (fl), Letouzey 11876 (BR, K). CENTRAL AFRICAN REPUBLIC. Boukoko, 17 Jan 1948 (fl), Tisserant 625 (BM, P). GABON. Ogooué-Ivindo: Bélinga, Mines de Fer, 700–900 m, 4 Jun 1966 (fr), Hallé 3735 (P).—Woleu-Ntem: ca. 9 km ESE Medouneu, Elot, bas inselberg Simanguen, 0°58.62'N, 10°54.01'E, 661 m, 21 Dec 2002 (fr), Ngok Banak et al. 1057 (MO); Inselberg, ca. 28 km ESE of Medouneu, 0°55'N, 11°01'E, 500 m, 3 Feb 1986 (fl, fr), Reitsma et al. 1821 (MO, NY, WAG). DEMOCRATIC REPUBLIC OF THE CONGO. Tshopo: Territ. Tsangi, Yangambi, 12 Feb 1952 (fl), Donis 3634 (K); Yangambi, 1938 (st), Gilbert 1099 (K, US); Yangambi, 1938 (buds) Gilbert 1423 (K, MO, US); Yangambi, 29 Nov 1935 (fl), Louis 733 (NY, RSA); Yangambi, 470 m, 17 Oct 1936 (yg fr), Louis 2741 (K); Yangambi, réserve-flore Isalowe, 7 Oct 1937 (st), Louis 6324 (FI-T, MO, P); Prov. Orientale, Territ. Tsangi, Yangambi, plateau de l’Isalowe, 12 Mar 1951 (fr), Toussaint 886 (K); Prov. Orientale, Tsangi Territory, Yangambi, environs de la Réserve floristique, Nov 1960 (fr), Yafunga 7 (WAG).

Xylopia gilbertii is either an uncommon or infrequently collected species. It can be recognized by a combination of the sparse but persistent erect pubescence of the twigs, leaves, and monocarps, the relatively broad but small flowers on short pedicels, and the rounded marginal glands on the inner petals. Xylopia gilbertii shares inner petal glands with X. flamignii and X. toussaintii, but the former has strongly reticulate leaves and more numerous, up to 22, glabrate monocarps, while the latter has proportionately narrower inner petals and less persistent indument of the twigs, leaves, and monocarps. An odd feature of X. gilbertii, not observed in the other two species or in fact in any African Xylopia, is the tendency for inflorescences to be produced at the bases of expanding shoots, such that it is difficult to determine the inflorescence position. Xylopia staudtii has occasionally been confused with X. gilbertii, but lacks the hairy twigs and leaves and the inner petal glands, and has larger and distinctly arillate seeds.

Descriptions of flower color for Xylopia gilbertii are inconsistent. Boutique (1951a), in the protologue for the species, described “Flores lutei,” but on the label of the holotype specimen, the flowers are described as “olive-fauve,” i.e. fawn-olive. Other collectors give flower colors such as brown-violet and purple, suggesting a darker color for the flowers. The lighter colors likely represent immature flowers. Endocarp color is unknown, but Gautier-Hion et al. (1985) reported that the seeds are dispersed by birds, monkeys, and small rodents, noting that the small rodents can also be predators on the seeds.

Sillans (1953), while mentioning X. gilbertii in the protologue for Xylopia ardua, did not explain how the two species were to be distinguished. The type specimen of X. ardua, while showing shorter and broader leaves than those of the type of X. gilbertii, overlaps widely with other specimens in both qualitative and quantitative characters, and we have thus placed it in synonomy. Two specimens from northern Gabon, Reitsma et al. 1821 and Ngok Banak et al. 1057, also with broader leaves, both differ somewhat from specimens elsewhere in having subcoriaceous leaves and longer stipes on the monocarps, but otherwise conform to this species.

We calculated an EOO of 249,251 km2 and an AOO of 52 km2 for Xylopia gilberti. It was given a conservation assessment of Vulnerable (D2) by Onana and Cheek (2011).

Xylopia gracilipes D. M. Johnson & N. A. Murray in Burrows et al., Trees and Shrubs of Mozambique, Taxonomic Notes, 1035–1039, fig. 2, 2018.

Figs 4F, 25A–L

Type

MOZAMBIQUE. Zambézia Province, Altomolócuè, Gilé, ao km 10, monte Gilé (Ig), 300 m, 21 Dec 1967, A. R. Torre & Correia 16681 (holotype: WAG).

Description

Tree up to 20 m tall or occasionally a shrub to 5 m, d.b.h. up to 20 cm, clear bole up to 4 m, sometimes ribbed, branches horizontal; bark light gray, sometimes mottled, smooth or flaking. Twigs reddish brown to brownish black, pubescent, the hairs 0.2–1.2 mm long, becoming gray to brown, glabrate, cross-cracked; nodes occasionally with two axillary branches. Leaf with larger blades 3.3–9.7 cm long, 1.7–4.1 cm wide, chartaceous to subcoriaceous, slightly discolorous, (narrowly) oblong to elliptic, occasionally lanceolate, elliptic-oblanceolate, or obovate, apex broadly acute, obtuse, or rounded, occasionally emarginate or acuminate with a broad acumen 1.5–7 mm long, base cuneate to obliquely rounded, rarely with some leaves on a specimen truncate, sparsely pubescent or with hairs restricted to the midrib adaxially, appressed-pubescent abaxially; midrib plane to slightly raised adaxially, raised abaxially, secondary veins weakly brochidodromous, 7–14 per side, diverging at 45–75° from the midrib, slightly raised on both surfaces, higher-order veins slightly raised on both surfaces but vein reticulum often more prominent adaxially; petiole 3.5–9.5 mm long, semi-terete or flattened to shallowly canaliculate, densely pubescent. Inflorescences axillary, 1–4-flowered; pedicels arising separately from axil, rarely 2 from a common peduncle, pubescent; peduncle, if present, 0.7–2.1 mm long; pedicels 2.7–8.5 mm long, 0.3–1.0 mm thick; bracts 2, usually one to either side of the midpoint, caducous to somewhat persistent, 1.3–1.6 mm long, ovate, apex obtuse; buds linear to lanceolate, straight to falciform, apex acute to obtuse. Sepals erect to slightly spreading at anthesis, 1/4–1/2-connate, 1.1–2.5 mm long, 1.8–3.0 mm wide, coriaceous, triangular to broadly ovate, apex acute, pubescent abaxially. Petals pale green or yellow in vivo; outer petals somewhat spreading at anthesis, 9.5–18.1 mm long, 2.5–3.0 mm wide at base, 0.8–1.8 mm wide at midpoint, coriaceous, linear to linear-lanceolate, attenuate, apex obtuse, channelled adaxially, keeled abaxially, gray-puberulent except for glabrous base adaxially, yellow-brown pubescent abaxially; inner petals curved outward to weakly geniculate at anthesis, 6.1–15.3 mm long, 1.5–2.5 mm wide at base, 0.4–1.1 mm wide at midpoint, coriaceous, linear-subulate, apex acute, base with undifferentiated margin, keeled on both surfaces, densely gray-puberulent on both surfaces except for glabrous base. Stamens ca. 120; fertile stamens 1.0–1.4 mm long, narrowly oblong, apex of connective 0.1–0.2 mm long, shieldlike, overhanging the anther thecae, glabrous, anthers ca. 9-locellate, filament 0.3–0.4 mm long; outer staminodes 0.9–1.3 mm long, oblong, apex irregularly truncate to rounded; inner staminodes 0.9–1.1 mm long, oblong to clavate, apex rounded; staminal cone 1.1–1.9 mm in diameter, 0.6–1.2 mm high, concealing only the bases of the ovaries, rim even or laciniate. Carpels 8–9; ovaries 0.8–1.1 mm long, narrowly oblong, ascending-pilose; stigmas more or less connivent, 1.6–3.3 mm long, linear, with a tuft of yellow hairs at the apex. Torus shallowly concave beneath ovaries, 1.5–2.7 mm in diameter. Fruit of up to 10 sparsely pubescent to glabrate monocarps borne on a pedicel 4.9–8.5 mm long, 2.2–4.8 mm thick, glabrate; torus 3.4–7.5 mm in diameter, 3.8–6.8 mm high, ovoid. Monocarps green with light green endocarp in vivo, 2.8–5.0 cm long, 0.8–1.1 cm wide, 0.8–0.9 cm thick, oblong, often irregularly torulose, apex obtuse with a broad blunt beak 2–3 mm long, base contracted into a stipe 4–11 mm long, 2–4.5 mm thick, obliquely wrinkled, verrucose, occasionally a little glaucous; pericarp ca. 0.4 mm thick. Seeds up to 5 per monocarp, in a single row, lying oblique to long axis, 9–12.2 mm long, 6.5–7.7 mm wide, 5.1–6.1 mm thick, ellipsoid, elliptic to semicircular in cross-section, narrowed and truncate at micropylar end, rounded at chalazal end, brown, smooth, dull, raphe/antiraphe not evident, micropylar scar 1.5–2.7 mm long, 1.0–2.3 mm wide, oblong; sarcotesta orange to red in vivo; aril absent.

Figure 25. 

Xylopia gracilipes and X. torrei. A–L X. gracilipes A Flower, side view B Base of outer petal, adaxial view C Base of inner petal, adaxial view D Flower, side view E Outer staminode, abaxial view F Fertile stamen, abaxial view G Habit H Fruit, side view I Leaf from same specimen as G J Close-up of twig pubescence K Seed, view of micropylar end L Seed, side view M–T X. torrei M Flower, side view N Base of outer petal, adaxial view O Base of inner petal, adaxial view P Habit Q Outer staminode, abaxial view R Fertile stamen, abaxial view S Close-up of twig pubescence T Fruit, side view. A–C, E–J from Torre & Correia 16681 (WAG) D from Renny 253 (PRE) K, L from Fidalgo de Carvalho 685 (MO) M–T from Goyder 5037 (K). Figure originally published in Burrows et al. (2018), reproduced with permission.

Phenology

Specimens with flowers have been collected in August and from October to February, and with fruits from January to March, and in May, October, November, and December. The specimens with flowers or fruits from outside of the October to February period are all from South Africa.

Distribution

(Fig. 26). Occurs from Tanzania south of the Rufiji River through Mozambique, where it is widespread, and then southwestward to eastern Zimbabwe and northeastern South Africa, in open miombo or other deciduous woodland, on rocky, sandy, or clay soils, at elevations of 40–1000 m. Associates include Albizia adianthifolia, Bosqueia phoberos, Catha edulis, Khaya nyasica, Lecomtodoxa henriquezii, and Monanthotaxis chasei, as well as species of Afzelia, Baphia, Bauhinia, Brachystegia, Dalbergia, Diospyros, Kigelia, Sclerocarya, and Sterculia. The species also occurs in an evergreen forest area of particularly high rainfall in eastern Zimbabwe, where the forest is described by Farrell (1960) as having a 100 ft (ca. 30 m) canopy layer, a 50 ft (ca.15 m) understory layer, and a shrub layer.

Local names

Garangerere (Simão 946), lòmué (Murroutho tôco-tôco, Andrada 1898), mugaranjerere (Chindao, Gomes Pedro 4224, 4394), mukáramo (D’Hondt 686), mulalabungo (Fidalgo de Carvalho 685), murikiriki (D’Hondt 686), murrouthonambuadji (Barbosa & Carvalho 2911), nionjono (D’Hondt 686), sangué (Torre & Correia 14168), sânguè (Namae, Andrada 1529,) tongolo (Tongo, Lamont 27984).

Figure 26. 

Distributions of Xylopia shirensis, X. odoratissima, X. holtzii, X. gracilipes, X. nilotica, and X. torrei. Bolder lines represent country borders, fainter lines lakes and major rivers.

Additional specimens examined

TANZANIA. Lindi: Lindi-Bezirk, Lutambasee, 240 m, 1 Nov 1934 (fl), Schlieben 5571 (BM, K, MO, P, PRE, US).—Mtwara: Mtwara District, 4.5 km S of Siwani Village on road from Mtwara to Maharunga and Rovuma R. mouth, 6 Nov 1978 (fl, fr), Magogo & Innes RRI 471 (EA, K, NHT). ZIMBABWE. Umtali District, Burma farm, Burma Valley, 30 Dec 1959 (fr), Chase 7238 (BM—2 sheets, MO); Chipinge [“Chipinga”] District, Upungura [Upungura Forest, in a Kloof at 2500–3000 ft. on the escarpment above Dumisayi], Feb 1960 (fr), Farrell 202 (MO); Chipinga District, Craigmore Farm, on the Nyagadza River W of Chirinda, 2800 ft, Oct 1968 (fl, fr), Goldsmith 159/68 (B, EA, MO, WAG—2 sheets); Melsetter District, forest on banks of lower Timbiri River, 14 Feb 1958 (st), Hall 469 (BM); Chipinga District, 2032 D1, ca. 4 km NE Musirizwe/Bwazi River confluence, ca. 540 m, 28 Jan 1975 (st), Pope et al. 1389 (MO, PRE); Melsetter District, Haroni River, 4 Dec 1965 (fl, fr), Wild et al. 6651 (BM). MOZAMBIQUE. Cabo Delgado or Niassa: Distrito de Metoro, Namacuto, 30 Jan 1984 (fl), Groenendijk et al. 856 (DSM, LMA—photo, MO, WAG).—Manica: Revue, 1 Oct 1946 (yg fr), Simão 946 (LMA—photo); Spungabera, próx. da Missão Católica, 14 Nov 1943 (fl), Torre 6192 (EA, LMA—photo, WAG); Dombe, entre Javera e Machire, a 6 km de Javera, 24 Oct 1953 (bud, fr), Gomes Pedro 4394 (BR); Spungabera, próx. da Missão Católica, 14 Nov 1943 (fl), Torre 6192 (EA, WAG); Moribane, entre Moribane e Sanguene, a 5 km de Moribane, 5 Oct 1953 (buds), Gomes Pedro 4224 (PRE); Dombe, picada Serração Braunstaine-Machango (Machonga), a ca. 7 km de Serração, 26 Feb 1965 (fl), Pereira & Marques 909 (LMA—photo).—Nampula: Prox. Serra Chinga, Estrada de Ribáuè, a ca. 28 km deste Poroação, 22 Oct 1968 (fl), Aguiar Macedo 3716 (LMA—photo); Ribáuè-Namina, perto de Ribáuè, 21 Oct 1982 (buds), D’Hondt 686 (LMA—photo); Monapo, andados 7 km de Itoculo para Nacala, (Ke), 4 Dec 1963 (fl), Torre & Paiva 9413 (EA, K).—Sofala: Gorongoza, Estrada de Vila Paiva de Andrada, a mais ou menos 5.5 km a cima cruz, Pávua, 22 Nov 1965 (fr), Aguiar Macedo & Balsinhas 1510 (LMA—photo); Búzi, Reserva Florestal do Mucheve (Talhões de ensaio), 28 Oct 1963 (fl, fr), Fidalgo de Carvalho 685 (MO); 40 km N of Dondo towards Muanza, Beira region, 10 May 1998 (fr), Lötter 261 (LYD—photo); 50 km N of Dondo, Beira region, 11 May 1998 (fr), Lötter 269 (LYD—photo); between Muanza and Chinizua, 13 May 1998 (fr), Lötter 284 (LYD—photo); Chissadze (Cheringoma), 29 Jun 1947, Simão 1326 (LMA—photo); Beira District, Gorongosa National Park, western park limits, Missicadzi track, Feb 1972 (st), Tinley 2382 (MO).—Zambézia: Namacurra, Estrada de Quelimane, perto de Naciaia, 28 May 1949, Andrada 1529 (LMA—photo); A. Molócuè, junto da Estrada para o Niponde, 24 Jul 1949, Andrada 1898 (LMA—photo); entre Mocuba e Quelimane a 95.2 km de Mocuba, 28 May 1949 (fr), Barbosa & Carvalho 2911 (LMA—photo); Bajone, entre Namuera & Murroa, 2 Oct 1949 (fr), Barbosa & Carvalho 4284 (LMA—photo); entrance road to Casa Branca, ca. 82 km from Nicoadala on Caia road, 29 Dec 2006 (fl), Burrows & Burrows 9848 (BPNR—image); Nante, distrito Maganja da Costa, 18 Jul 1978, Macuácua 578 (LMA—photo); Maganja da Costa, ao km 23, estrada para Namacurra (Hh), 40 m, 27 Jan 1966 (fl), Torre & Correia 14168 (PRE). SOUTH AFRICA. Limpopo: [“Transvaal”], Zoutpansberg District, Eubabeni (klein Australië), 800 m, 11 Aug 1980 (fl), von Breitenbach 16459 (PRE); Zoutpansberg District, Funduzi, 23 Jan 1931 (fl), Bremekamp & Schweickerdt 348 (PRE); Transvaal, Zoutpansberg District, Makonde Mission Station, 15 mi NE of Sibasa, 2500 ft, 18 Feb 1952 (st), Codd 6806 (K); Sikorora [near Leydsdorp] nr. Macoutsie Riv., Dec 1922 (fl), van Dam 22934 (PRE); Pietersburg Tul., Letaba, New Agatha, Forestry Department s. n. (K—2 sheets); Venda, Messina, Mabila village, SE of Nwanedi Game Park, 15 Jan 1989 (fr), Hardy 6914 (PRE); 2230 BD (Messina), Phiphidi, 15 Nov 1978 (fl), Hemm 881 (MO); Woodbush, N. Transvaal, Dec 1928 (fl, fr), Hutchinson 2240 (K); Shilowane, Oct–Nov (fl), Junod 1427 (K); road between Mufulwi and Makuleni, 997 m, 22°42'06"S, 30°28'32"E, 17 Jan 2004 (fr), Klein 767 (K); Regio Zoutpansberg, Punda Maria, K. N. P., Dec 1945 (buds), Lamont 27984 (PRE); Zoutpansberg District, Elim, Dec 1930 (st), Obermeyer 839 (PRE); Distr. Letaba, Cyprus farm, slopes of Kopje, 23 Nov 1968 (fl), Renny 253 (PRE); E. Transvaal, Dist. Punda Maria, 15 Oct 1952 (buds, fr), v. d. Schijff 969 (K); Kruger National Park, Shipudza, NW of Punda Maria, 1700 feet, 24 May 1954, v. d. Schijff 3779 (EA, K, L, MO); Dist. Krugerpark, Wambia, 2 Jun 1961 (st), v. d. Schijff 5686 (K); New Agatha - Trl., Letaba District, Feb 1933 (fl), Schnetler 8177 (PRE); Lekgalameetse Nat. Res., Balloon, near entrance gate of reserve, 26 Nov 1985 (fl), Stalmans 285 (K—2 sheets); Nor Transvaal, Zoutpansberg, Njelele - Tol, 10 Feb 1951 (fl, fr), Stopp M79 (M); Farm Balloon 71 KT, along Makhuiswi road, 860 m, 2 Aug 1983 (fr), Venter 9808 (LYD—photo); Dist. Sibasa, Ishakhuma, 23°03'S, 30°18'E, 2100 ft, 9 May 1951 (fr), van Warmelo 5159/14 (K); Dist. Sibasa, Rambuda, Loen., 22°47'S, 30°21'E, 2400 ft, 19 Dec 1951 (fl), van Warmelo 51219/7 (K); northern Transvaal, Sibasa District - Venda, 22°30° DA, next to tar road between Thengwe and Sagole Spa near top of mountain pass, 923 m, 31 Mar 1994 (fr), van Wyk BSA 2023 (PRE).

Xylopia gracilipes can be separated from its congeners by elliptic to oblong leaf blades that are cuneate to broadly cuneate at the base, axillary inflorescences of 1–2 pedicels 0.3–1.0 mm thick arising separately from the axil, outer petals no more than c. 18 mm in length and obtuse at the apex. In addition, the petals are uniformly pale green to yellow and lack purple coloration on the inner base.

Robson (1960) cited two of the Mozambique collections (Barbosa & Carvalho 4284, Torre 6192) as X. holtzii. He used the specimen Hutchinson 2240 from South Africa as the basis for the illustration of Xylopia holtzii in the same work (tab. 14, figs A1–A7). Similarly, Verdcourt (1971b) identified the specimen Schlieben 5571 from the Lindi Region of southern Tanzania as “X. parviflora,” i.e. Xylopia holtzii s. s. (see Johnson et al. 2017 for explanation). A study of a wider range of material than was available to these authors, supplemented with field knowledge of the plants in Mozambique shared by Mervyn Lötter, has shown that this species differs from Xylopia holtzii in a number of characters. The leaf blades, while somewhat variable in size and shape, are on the average smaller (3.3–9.7 cm long) and tend to be elliptic to oblong. The pedicels arise side by side in the inflorescences, and are more slender. The monocarps by maturity are glabrate. In contrast, in X. holtzii the leaf blades are slightly larger (4.8–11.4 cm long) and lanceolate or rarely narrowly oblong, most inflorescences have pedicels branching from a common peduncle, and the mature monocarps are persistently pubescent. Furthermore, the outer petals of X. holtzii, while green to yellow in color like those of X. gracilipes, are marked with a purple blotch on the inner base, are acute at the apex, and reach a length of 25 mm.

Xylopia gracilipes also resembles Xylopia shirensis, with which it is not known to overlap in range, but it has narrower leaf blades cuneate to broadly cuneate at the base and more slender (0.3–1.0 mm thick) pedicels; in contrast, the leaf blades in X. shirensis are proportionally broader and usually rounded to truncate at the base, and the pedicels, while of the same length as those of X. gracilipes, are instead 1.2–1.5 mm thick.

Some variants need further field study. The hairs on the specimen Groenendijk et al. 856 are longer and more abundant than is otherwise typical for the species, and the leaves of specimens from the Venda area of South Africa (e.g., van Wyk BSA 2023) are much smaller and more rounded than those from elsewhere in the distribution.

Xylopia holtzii Engler, Bot. Jahrb. Syst. 34: 159. 1904.

Figs 27G–K, 28A

Type

TANZANIA. Dar-es-Salaam Region, Dar-es-Salam, Puguberge, Dichter Busch, 29 Feb 1903, W. Holtz s. n. (lectotype, here designated: B! [100153143]).

Tree up to 20 m tall, d.b.h. up to 30 cm, clear bole to 8 m on 12 m tree, trunk fluted or with small narrow buttresses at base; bark light gray to gray-brown, sometimes blotched with white, smooth or transversely ringed by fine lenticels. Twigs light brown, orange-brown, gray-brown, brownish gray, or blackish brown, initially pubescent, the hairs 0.1–0.8 mm long, becoming glabrate; nodes occasionally with two axillary branches. Leaf with larger blades 4.8–11.4 cm long, 1.7–4.4 cm wide, chartaceous to subcoriaceous, concolorous to slightly discolorous, lanceolate to narrowly oblong, elliptic, or oblanceolate, apex obtuse, often attenuate, rarely emarginate, base broadly cuneate to rounded, glabrous to sparsely pubescent adaxially, sparsely appressed-pubescent abaxially; midrib slightly raised to plane adaxially, raised abaxially, secondary veins weakly brochidodromous, 8–17 per side, diverging at 40–70° from the midrib, slightly raised on both surfaces, higher-order veins indistinct adaxially, indistinct to slightly raised abaxially; petiole 3–12 mm long, shallowly canaliculate to flattened, pubescent or rarely glabrous. Inflorescences axillary, 1–6-flowered, pubescent; at least some inflorescences with peduncles, 1-2 peduncles per axil, 2–4.5 mm long; pedicels 2–4 per peduncle, or arising directly from axil, 2.0–7.5 mm long, 0.7–0.8 mm thick; bracts 2–3, evenly spaced along length of pedicel, caducous or rarely persistent, 0.9–1.3 mm long, ovate to semicircular, apex acute to rounded; buds linear, slightly falciform, apex acute. Sepals erect to slightly spreading at anthesis, 2/5–1/2-connate, 1.6–2.4 mm long, 1.9–2.8 mm wide, coriaceous, orbicular, apex acute to short-acuminate, appressed-pubescent abaxially. Petals yellow-green, yellow, or cream-colored with pinkish purple at the base adaxially in vivo; outer petals curved outward but with the apices weakly incurved at anthesis, 10.5–25 mm long, 2.1–3.7 mm wide at base, (0.7–) 0.9–1.9 mm wide at midpoint, coriaceous, linear, apex acute to obtuse, weakly keeled on abaxial surface, gray-puberulent adaxially, golden appressed-pubescent abaxially; inner petals curved outward but with the apices strongly incurved at anthesis, 7.7–21.4 mm long, 1.6–2.7 mm wide at base, 0.5–1.2 mm wide at midpoint, coriaceous, linear-subulate, apex acute, base with undifferentiated margin, ridged on both surfaces, densely puberulent on both surfaces. Stamens 60–70; fertile stamens 1.0–1.5 mm long, narrowly oblong, apex of connective red to reddish purple in vivo, 0.1–0.3 mm long, shieldlike, overhanging anther thecae, glabrous, anthers 10–13-locellate, filament 0.3–0.5 mm long; outer staminodes 0.9–1.4 mm long, quadrate to broadly clavate, apex truncate; inner staminodes 1.0–1.2 mm long, clavate, apex truncate; staminal cone 0.7–1.9 mm in diameter, 0.7–1.1 mm high, concealing only the bases of the ovaries, rim laciniate. Carpels 5–12; ovaries 0.9–1.1 mm long, narrowly oblong, pubescent; stigmas loosely connivent, 0.9–1.8 mm long, linear, apices pubescent. Torus flat, 1.6–2.4 mm in diameter. Fruit of up to 8 pubescent monocarps borne on a pedicel 4.5–8 mm long, 1.6–3.0 mm thick, pubescent; torus 3.0–6.7 mm in diameter, 2.6–5.4 mm high, irregularly globose. Monocarps with green exterior and white (immature?) endocarp in vivo, up to 8 per fruit, 2.3–4.0 cm long, 0.8–1.3 cm wide, 0.7–0.8 cm thick, oblong, irregularly torulose, apex obtuse to rounded, often with a wide beak 1.5–2.2 mm long, base contracted into a stipe 6–10 mm long, 3–3.5 mm thick, finely verrucose, pubescence most persistent on stipe; pericarp 0.4–1.0 mm thick. Seeds 1–3 per monocarp, in a single row, lying oblique to long axis, 11.8–12.3 mm long, 5.9–7.0 mm wide, 4.9–6.0 mm thick, flattened-ellipsoid, broadly elliptic in cross-section, obliquely truncate at micropylar end, rounded at chalazal end, brown, smooth, shiny, raphe/antiraphe not evident, micropylar scar 1.4–1.9 mm long, 0.9–1.0 mm wide, oblong, elliptic, or ovate-elliptic; sarcotesta orange in vivo; aril absent.

Figure 27. 

Xylopia longipetala, X. holtzii, X. katangensis, and X. shirensis. A–F X. longipetala A Fruit B Seed, side view C Seed, view of micropylar end D Base of inner petal, adaxial view E Habit F Gynoecium surrounded by staminal cone with a few attached stamens G–K X. holtzii G Habit H, I Detached monocarps J Gynoecium surrounded by staminal cone with a few attached stamens K Base of inner petal, inner (adaxial) surface L X. katangensis, habit M–P X. shirensis M Fruit N Habit O Seed, view of micropylar end P Seed, side view. A–C from Jongkind & Nieuwenhuis 3031 (WAG) D, F from McPherson 17911 (MO) E from Hallé & Le Thomas 190 (P), and following photograph of fresh flowers of same collection in Le Thomas (1969) G, J, K from Johnson et al. 1938 (OWU) H, I from Templer H167/53 (K), L from Letouzey 4498 (MO) M from Richards 13266 (K) N from Richards 14438 (K) O, P from Bredo 6276 (BR).

Phenology

Specimens with flowers have been collected in February, March, from May to July, and from October to December, and with fruits from January to March, in May and August, and from October to December.

Distribution

(Fig. 26). Occurs near the Indian Ocean coast from southern Kenya to central Tanzania, extending inland in Tanzania to the scarp of the Udzungwa Mountains and the Selous region, growing in dry evergreen or semi-deciduous forest, less commonly in miombo (Brachystegia) woodland, at elevations of 0–800 (–1670) m.

Local names

Lulema mbala (Rodgers 388); mlawilila (Kidoe, Abeid 550), muporota (Kihehe, Haerdi 214/0), mporoto (Kimbunga, Haerdi 214/0), mporota (Kisagara, Haerdi 214/0). An ethnobotanical study of the Digo people on the coast between Tanga and Mombasa reported mnyinyi [shining leaves], mchiza tasaka, and mwahula tsaka [forest breaker, i.e. emergent through the canopy] (Pakia 2005) as additional local names in that area.

Additional specimens examined

KENYA. Kwale: Jardini, Jun 1962 (fl), Birch 62/188 (K); Jilori, Black M.37 (K); Kwale District, Mwasangombe Forest 15 km SW of Kwale, 230 m, 27 Aug 1953 (fr), Drummond & Hemsley 4015 (B, EA, FI-T, K); Jardini Hotel, forest ca. 30 km S of Mombasa, 22-23 Jun 1970 (fl), Faden 70/201 (EA, K, MO); Diani Forest, 1 km N to 1.5 km S of the turnoff for the new road to Jadini Hotel, 4°19'S, 11–13 Jul 1972 (fl), Gillett & Kibuwa 19846 (B, BR, EA, K, MO, NHT, P, WAG); Gillett & Kibuwa 19847 (K); Mkongani North FR, 4°17'S, 39°19'E, 280 m, 13 Jul 1987 (bud), Luke & Robertson 508 (MO); Diani Forest, 4°20'S, 39°34'E, 5 m, 16 Jun 1994 (fl), Robertson 6957 (K, MO); Mrima Hill, 4°29'S, 39°16'E, 170 m, 4 Feb 1989 (st), Robertson et al. MDE 50 (K); Gogoni, 30 mi S of Mombasa, 7 Oct 1953 (fl, fr), Templer H167/53 (K–2 sheets, MO).—Lamu: Witu District, Mambasasa, 7 Nov 1957 (old fl), Greenway 9471 (FI-T, K, PRE). TANZANIA. Iringa: Kilolo District, Kisegese Village, at base of hill, 08°01'58"S, 036°22'46"E, 360 m, 13 Mar 2006 (fl, fr), Festo et al. 2213 (MO).—Lindi: Selous Game Reserve, T8, ca. 15 km SSW of Kingupira, 8°35'S, 38°31'E, ca. 150 m, 15 Nov 1975 (fl), Vollesen 2992 (K, WAG).—Morogoro: Hundupila/Kiberege, Ifakara, 6 Mar 1959 (fl), Haerdi 214/0 (K, WAG); along trail to Mwanihana Peak, SW of Udzungwa Mountains National Park headquarters, 19/20 Feb 1996 (fl, fr), Johnson & Murray 1889 (OWU spirit collection); Ulanga District, Iragua village, 100 m SE of main road from Iragua to Itete, 8°33'54"S, 36°29'52"E, 360 m, 21 Jan 1999 (fr), Kayombo 1589 (MO); Sanje Logging Camp, 1670 m, 30 Dec 1980 (fr), Rodgers 388 (DSM).—Pwani: Bagamoyo District, Zaraninge Forest Reserve, near WWF office, near forest guards’ camp, 6°17'S, 38°34'E, 150 m, 8 Jun 1999 (fl), Abeid 550 (MO); Pugu-Berge, s. d., Holtz 3202 (B, PH); Coast Region, Kisarawe District, Pugu Forest Reserve, bus roundabout area ca. 4 km E of Kisarawe, 06°53'30"S, 39°06'00"E, 200 m, 26 May 1996 (fl), Johnson & Murray 1938 (OWU); Rufiji District, forest near WWF Office, 08°18'57"S, 38°57'39"E, 250 m, 6 Dec 1998 (fl), Kibure 320 (MO); T6, Kisarawe, Pugu Forest Reserve, June 1954 (fl), Semsei 1718 (EA, K—2 sheets); Selous Game Reserve, Beho Beho, 07°40'S, 37°55'E, 250 m, 6 Jun 1977 (fl), Vollesen 4619 (DSM, WAG).—Tanga: Kihuhwi R., E Usambaras, 900 ft, Greenway 4959 (K).—Region undetermined: T6, Nahomba, Selous Game Reserve, 7 Nov 1970 (fr), Ludanga 1166 (K); Kijawe, Selous Game Preserve, 2 Feb 1971 (fl), Ludanga 1193 (EA, K); T6, Selous Game Reserve, 24 May 1978 (fr), Mhoro 2917 (MO); T8, Balani water hole, Selous Game Reserve, 4 Oct 1970 (fl), Rodgers 1148 (K).

Xylopia holtzii is another member of the X. odoratissima subgroup of eastern and southern Africa, set apart from other species of the subgroup by the combination of branched inflorescences, purple coloration at the bases of the petals, and pubescent stipitate monocarps that are only weakly verrucose. The number of branched inflorescences on herbarium specimens varies—some sheets of Vollesen 2992 from the Selous region, for example, have no branched inflorescences, but correspond to the species in leaf and floral morphology. In Tanzania, X. holtzii is not known to overlap in distribution with either X. shirensis or X. gracilipes. The former is a species of the interior miombo woodlands to the west of the Eastern Arc Mountains, while the latter is only known from the miombo woodlands of the extreme southern Tanzania, where it reaches the northern limit of its distribution.

Given the variable nature of the habitats in which this species occurs, it is not surprising that tree associates vary correspondingly from location to location. The most frequently mentioned associates are Milicia excelsa and species of Erythrophleum and Diospyros. Marshall (2007) reported X. holtzii (as X. parviflora) to be one of the ten most common canopy tree species in disturbed semi-deciduous forest plots in the Udzungwa Mountains, comprising 7.5% of the 3346 canopy tree individuals sampled.

The type specimen of Xylopia holtzii cited above, which was marked as the Typus at B, bears information slightly different from that which is included in Engler’s protologue: “Sansibarküstgebiet: Pugu-Berge in Buschgehölzen auf rotem Lehm (Holtz n. 897 – Fruchtend im Feb 1903).” The specimen is not discordant with the protologue, but in the case that there was a specimen with this number that has now been lost, the extant specimen is designated as a lectotype rather than assumed to be the holotype.

Xylopia keniensis D. M. Johnson, Kew Bull. 72:11: 10–12. 2017.

Fig. 28C–E

Type

KENYA. Kwale District, Shimba Hills, 4.2407°S, 39.4218°E, 390 m, 30 Dec 2009, Q. Luke & P. Luke 13949 (holotype EA!; isotypes BR, K! MO! [6467367, 6569824], NHT, PRE, US).

Description

Tree 15–25 m tall with long straight bole and rounded crown. Twigs greenish brown to blackish, glabrous or initially short-pubescent, the hairs 0.1–0.3 mm long, but soon light gray, glabrate; nodes occasionally with two axillary branches. Leaf with larger blades 6.7–10.5 cm long, 2.6–3.7 cm wide, chartaceous, shiny adaxially, dull and paler abaxially, lanceolate to elliptic, occasionally oblong or elliptic-oblanceolate, apex sharply acuminate, the acumen 6–18 mm long, occasionally obtuse, base cuneate to rounded, glabrous or with a few hairs at the base of the midrib adaxially, sparsely appressed-pubescent to glabrate abaxially; midrib slightly raised to plane adaxially, raised abaxially, secondary veins weakly brochidodromous, 12–15 per side, diverging at 60–75° from the midrib, these and higher order veins slightly raised on both surfaces; petiole 2–5.5 mm long, shallowly canaliculate, pubescent to glabrous. Inflorescences axillary, usually from the axils of fallen leaves, 1- or rarely 2-flowered, sparsely pubescent; pedicels 2.8–3.9 mm long, 0.6–0.7 mm thick; bracts 2, attached to the distal half of the pedicel, persistent or not, 1.2–1.6 mm long, broadly ovate to crescent-shaped, apex acute; buds lanceolate, apex acute. Sepals erect to slightly spreading at anthesis, 1/3-connate, 2.2–2.7 mm long, 2.3–2.4 mm wide, subcoriaceous, broadly ovate to triangular, apex obtuse to acute, sparsely pubescent abaxially. Petals cream-colored with reddish pink bases at anthesis in vivo; outer petals erect or slightly spreading at anthesis, 13.7–19.3 mm long, 2.2–2.6 mm wide at base, 0.9–1.0 mm wide at midpoint, coriaceous, linear, flat on both surfaces, apex obtuse, densely puberulent except for the glabrous warty base adaxially, golden-sericeous abaxially; inner petals geniculate at anthesis, with the apices bent sharply outward between the outer petals, 11.0–16.3 mm long, 1.8–2.2 mm wide at base, ca. 0.5 mm wide at midpoint, coriaceous, linear-subulate, longitudinally ridged on both surfaces, transversely thickened at widest point adaxially, apex acute, base with undifferentiated margin, densely puberulent on both surfaces except for the glabrous base. Stamens ca. 85; fertile stamens 1.0–1.3 mm long, narrowly oblong, apex of connective reddish pink at anthesis in vivo, 0.2–0.25 mm long, shieldlike, overhanging the anther thecae, smooth or finely papillate, anthers 7–10-locellate, filament 0.3–0.5 mm long; outer staminodes 1.2–1.5 mm long, oblong, apex rounded to truncate, sometimes emarginate; inner staminodes 1.0–1.1 mm long, oblong, apex truncate; staminal cone ca. 1.3 mm in diameter, 0.7 mm high, concealing only the bases of the ovaries, rim laciniate. Carpels ca. 6; ovaries ca. 0.3 mm long, oblong, pubescent; stigmas connivent, free at the apices, 1.8–2 mm long, filiform, apex acute, with a few hairs at the apices. Torus flat, ca. 1.8 mm in diameter Fruit of up to 4 glabrate monocarps borne on a pedicel ca. 5 mm long, ca. 2.6 mm thick, glabrate; torus ca. 4 mm in diameter, ca. 4.5 mm high, globose. Monocarps with a green exterior and red endocarp in vivo, 2.8–3.5 cm long, 1.0–1.6 cm wide, 1.1–1.4 cm thick, clavate-pyriform to ovoid, usually with a longitudinal ridge running down one side, apex obtuse, base tapered but not stipitate, verrucose; pericarp 0.4–1.0 mm thick. Seeds 4–6 per monocarp, in two rows, lying perpendicular to long axis, 11.0–11.2 mm long, 7.2–7.3 mm wide, ca. 5.1 mm thick, oblong to ellipsoid, obovate to elliptic in cross-section, obliquely truncate at micropylar end, rounded at chalazal end, dark brown, slightly wrinkled/roughened, dull, raphe/antiraphe not evident, micropylar scar ca. 3 mm long, 1.5 mm wide, elliptic; sarcotesta orange-red in vivo; aril absent.

Figure 28. 

Xylopia keniensis and X. tanganyikensis, with leaves of X. holtzii and X. longipetala for comparison. A Leaf of X. holtzii from Tanzania B Leaf of X. longipetala from Ghana C–E X. keniensis C Habit D Fruit E Inflorescence F–O X. tanganyikensis F Pedicel, sepals, and staminal cone G Base of inner petal, adaxial view H Base of outer petal, adaxial view I Flower, lateral view J Carpel K, L Habit M Stamen, abaxial view N Staminode, abaxial view O Fruit. A from Semsei 1718 (K) B from Jongkind & Nieuwenhuis 2130 (WAG) C, D from Luke & Robertson 2723 (MO) F–J, L–N from Nishida 57 (K) K, O from Abeid et al. 1028 (L). Reproduced with the permission of the Board of Trustees, Royal Botanic Gardens Kew.

Phenology

Specimens with flowers or flower buds have been collected in November and December, and with fruits in March and September.

Distribution

(Fig. 22). Endemic to the Shimba Hills region of southern Kenya, where it grows in lowland forest at elevations of 350–430 m (Luke 2005). Associates at one site (from Luke & Robertson 2723) included species of Antiaris, Milicia, Lovoa, Celtis, Quassia, Hymenaea, Julbernardia, and Manilkara in the canopy, and Leptonychia, Diospyros, Warneckea [Memecylon], and many Rubiaceae shrubs in the understory.

Additional specimens examined

KENYA. Kwale: Shimba Hills, Makadara, 4.2394 S 39.3937 E, 430 m, [typed label gives locality as Taita Hills, which is a transcription error (R. Faden, personal communication)], 9 Nov 1970 (buds), Faden et al. 70/847 (K); Shimba Hills, Longomwagandi, 4.2407 S 39.42181 E, 390 m, 30 Dec 2009 (st seedling), Luke & Luke 13950 (EA); Shimba Hills, Longomwagandi, 4.2351 S 39.4181 E, 390 m, 17 March 1991 (fr), Luke & Robertson 2723 (EA, K, MO); Shimba Hills, 1 Jul 2006, Project Mbegu 353 (EA); Shimba Hills, 20 Jul 1967 (st), Mulwa 015 (EA); Kwale District, Shimba Hills, Lango ya Mwagandi or Longo Mwagandi Forest, 4.2333 S, 39.4167 E, 350 m, 18 Sep 1982 (fr), Polhill & Robertson 4800 (K).

Xylopia keniensis overlaps in distribution with X. holtzii, but it differs from that species in the sharply acuminate and nearly glabrous leaf blades, the pedicels short and usually with only one flower per axil, the inner petals strongly geniculate at anthesis, and the sessile monocarps with the seeds arranged in two rows. In seedlings grown side by side, the more pronounced sheen of the X. keniensis leaves is evident (Q. Luke, personal communication).

The species is likely to occur in the Usambara Mountains region of Tanzania, where it may be confused with X. holtzii. As currently known, X. keniensis is very rare, and was given a conservation assessment of Endangered B1ab(iii)+B2ad(iii) by Johnson et al. (2017). We determined it to have the smallest AOO of any African species, 10 km2.

Xylopia nilotica D. M. Johnson & N. A. Murray, sp. nov.

Fig. 29

Diagnosis

Species resembling Xylopia holtzii in its branched inflorescences and leaf blades adaxially hairy, but differing in the higher-order veins of the leaf equal in prominence to the secondary veins and forming a conspicuous raised reticulum on the adaxial surface, and the monocarps conspicuously verrucose but not much wrinkled, with stipes 3.5–5 mm thick.

Type: UGANDA. Northern Region, Leya and Aiyu river junction, W. Madi, 25 Mar 1945, P. J. Greenway & W. J. Eggeling 7251 (holotype: EA!; isotypes: K! PRE!).

Description

Tree up to 25 m tall with a narrow crown, bole straight, fluted with small sharp buttresses at the base; bark light gray to grayish brown, sometimes exfoliating in irregular patches. Twigs brown to reddish brown, brownish gray, or blackish brown, sparsely pubescent, the hairs 0.2–0.5 mm long, eventually brownish black to dark gray, glabrate; nodes occasionally with two axillary branches. Leaf with larger blades (4.1–) 6.1–9.4 cm long, 2.2–3.2 cm wide, chartaceous, concolorous, oblong to lanceolate-oblong, apex obtuse to rounded, occasionally retuse or emarginate, base obliquely cuneate to rounded, sparsely pubescent (densest on the midrib) to glabrous adaxially, sparsely appressed-pubescent abaxially; midrib slightly raised to plane adaxially, raised abaxially, secondary veins weakly brochidodromous, 8–13 per side, diverging at 40–70° from the midrib, these and higher-order veins raised on both surfaces; petiole 3.5–8 mm long, semi-terete to shallowly canaliculate, pubescent. Inflorescences axillary, 1–3-flowered, pubescent; peduncle 1 per axil, 2.0–5.5 mm long; pedicels 2–3 per peduncle, (1.0–) 2.5–7.5 mm long, 0.5–0.9 mm thick; bracts 2, at or just distal to the pedicel midpoint, caducous or the uppermost persistent, ca. 1.6 mm long, broadly ovate, apex obtuse; buds linear-lanceolate, slightly falciform, apex acute, base globose. Sepals slightly spreading at anthesis, 1/3–1/2-connate, 1.5–2.5 mm long, 2.2–3.3 mm wide, coriaceous, semicircular to broadly triangular, apex acute, pubescent abaxially. Petals pale green to yellow-green in vivo; outer petals erect to somewhat spreading at anthesis, 11.7–27 mm long, 2.3–2.9 mm wide at base, 1.0–1.2 mm wide at midpoint, coriaceous, linear, apex acute, longitudinally ridged on abaxial surface, gray-puberulent except for glabrous base adaxially, golden-pubescent abaxially; inner petals curved outward or weakly geniculate at anthesis, 11.5–16.8 mm long, ca. 2.4 mm wide at base, ca. 0.7 mm wide at midpoint, coriaceous, linear-subulate, apex acute, base with undifferentiated margin, longitudinally ridged on both surfaces, densely puberulent on both surfaces except for the glabrous base. Stamens ca. 70–80; fertile stamens 1.0–1.3 mm long, narrowly oblong, apex of connective 0.1–0.2 mm long, depressed-globose to shieldlike, overhanging the anther thecae, glabrous, anthers 8–11-locellate, filament 0.3–0.5 mm long; outer staminodes 1–1.3 mm long, broadly clavate, apex rounded to truncate; inner staminodes 0.8–1 mm long, clavate, apex truncate; staminal cone 0.8–1.9 mm in diameter, 0.7–1.1 mm high, concealing only the bases of the ovaries, rim even to laciniate. Carpels ca. 7; ovaries 0.8–0.9 mm long, narrowly oblong, pubescent, stigmas loosely connivent, 2–2.5 mm long, linear, apices pubescent. Torus flat, 1.6–2.7 mm in diameter. Fruit of up to 12 sparsely pubescent monocarps borne on a pedicel 7–8.5 mm long, 2.5 mm thick, glabrate; torus 5–7.5 mm in diameter, 5.5–7 mm high, globose to depressed-globose. Monocarps 2.3–4.2 cm long, 0.9–1.3 cm wide, ca. 1.2 cm thick, oblong, weakly torulose, apex obtuse to rounded and somewhat flattened, base contracted into a stipe 6–9 mm long, 3.5–5 mm thick, obliquely wrinkled, strongly verrucose; pericarp 1 mm thick. Seeds up to 3 per monocarp, in a single row, lying oblique to long axis, 11.8–12.5 mm long, ca. 6.7 mm wide, ca. 5.8 mm thick, oblong-ellipsoid, semicircular in cross-section, narrowed and truncate at micropylar end, rounded at chalazal end, brown, smooth, shiny or dull, raphe/antiraphe not evident, micropylar scar ca. 2 mm long, ca. 1.5 mm wide, elliptic; sarcotesta red to orange in vivo; aril absent.

Figure 29. 

Xylopia nilotica. A Close-up of inflorescence, showing two pedicels branching from the same peduncle B Flower bud, lateral view C Receptacle with petals, stigmas, and most of the stamens fallen, showing staminal cone D Base of outer petal, adaxial view E Base of inner petal, adaxial view F Fertile stamen, abaxial view G Outer staminode, abaxial view H Leaf I Habit, including leaves and fruit J Seed, view of micropylar end and side view. A, H from Greenway & Eggeling 7251 (K) B from Wood 610 (K) C–G from Philip 931 (K) I from Greenway & Eggeling 7251 (PRE) J from Smith 39 (K).

Phenology

Specimens with flowers have been collected from February to May and in July, and with fruits from March to May.

Distribution

(Fig. 26). Occurs in upland and lower montane semideciduous forests, one specimen from along a river, in central Sudan, South Sudan, and northern Uganda, all from the upper Nile River watershed, at elevations between 760 and 1220 m.

Local names

Kharûm (Eliri Arab, Simpson 7778), munnu (Anuak, Simpson 7778).

Additional specimens examined

SUDAN. Gebel Amira, Nuba Mts., 16 Apr 1930 (buds), Simpson 7778 (K—2 sheets); Eastern KMagnolialesfan Province, Jebel Dair, 4000 ft, 17 Jul 1937 (fl), Turner 241 (K). SOUTH SUDAN. West Equatoria: “Large tree of Azza,” [Azza forest is probably SE of Maridi, I. Darbyshire, personal communication, 2016], 28 Apr 1933 (fr), Smith 39 (K). UGANDA. West Nile, Koich River, Rumogi, Mar 1935 (fl), Eggeling 1650 (K); Madi, 830 m, Feb 1961 (fl), Philip 931 (EA, K); Murchison Falls National Park, Rabongo Forest, 02°06'N, 31°52'E, 1020 m, 1 May 1993 (fl, fr), Sheil 1443 (K); Busoga District, Igwe mutalla, 10 mi S of Bugiri, 1260 m, 20 May 1951 (fl), Wood 610 (EA, K—2 sheets).

Xylopia nilotica is most similar to X. holtzii of coastal Kenya and Tanzania, but is distinguished by the more prominent and raised reticulum of the adaxial leaf surface, with the higher-order veins equal in prominence to the secondary veins, and the strongly verrucose monocarps with thicker stipes. While Xylopia nilotica is more similar to X. holtzii than to X. longipetala, it is nearer to the latter geographically, differing in being a large forest tree of upland or even submontane forest rather than a riparian shrub or small tree, and in having much shorter petals and distinctly stipitate monocarps.

Xylopia nilotica occupies the northernmost distribution of any Xylopia species in Africa. Associates occurring at more than one locality include Holoptelea grandis, Milicia excelsa, and species of Khaya. Several sterile specimens probably represent this species: SUDAN: Broun & Broun 1373 (K), Longe 40, local name dooru (K), Myers 10102 (K); ETHIOPIA: Chaffey & Thomerson 658, local name orowyee (Anuak) (EA, K), Friis et al. 2485 (K).

Xylopia odoratissima Welwitsch ex Oliver, Fl. trop. Afr. 1: 31. 1868.

Fig. 3G

Xylopicrum odoratissimum (Welwitsch ex Oliver) Kuntze, Revis. gen. pl. 1: 8. 1891. Type. ANGOLA. Huíla Province, [Morro de Lopollo, 1859-60, ex Hiern (1896, p. 10)], F. Welwitsch distrib. no. 757 (lectotype: BM! [000511059, flowering specimen on lower half of sheet], photos GH! NY!).

Xylopia antunesii Engler & Diels, Notizbl. Königl. Bot. Gart. Berlin 2: 299. 1899.

Xylopicrum antunesii (Engler & Diels) Kuntze, Deutsch. Bot. Monatsschr. 21: 173–174. 1903. Type. ANGOLA. Benguella, Huíla, J. M. Antunes 64 (holotype: B! [100153150]).

Description

Shrub or tree up to 9 m tall, d.b.h. up to 15 cm, with wide-spreading crown; bark light gray to brown, smooth or flaking. Twigs brown to dark brown, densely pubescent, the hairs 0.2–0.6 mm long, eventually light gray, reddish brown or brownish gray, glabrate; nodes occasionally with two axillary branches. Leaf with larger blades 4.7–6.9 cm long, 2.2–3.3 cm wide, subcoriaceous to chartaceous, concolorous, oblong, lanceolate-oblong, or elliptic, occasionally ovate, oblanceolate, or obovate, apex obtuse or rounded, occasionally broadly acute, base broadly cuneate to rounded, sparsely pubescent (usually denser on the midrib) adaxially, pubescent abaxially; midrib raised to plane adaxially, raised abaxially, secondary veins weakly brochidodromous to camptodromous, 6–11 per side, diverging at 45–70° from the midrib, slightly raised on both surfaces, higher-order veins raised on both surfaces; petiole 3.5–8 mm long, shallowly canaliculate, densely pubescent. Inflorescences axillary, 1–3-flowered, the pedicels arising separately from axil, only rarely 2 from a short common peduncle, pubescent; pedicels 3.5–7 mm long, 1.3–1.5 mm thick, pubescent; bracts 1–2, attached near the midpoint, caducous, 1.1–2 mm long, semicircular, apex obtuse to rounded, pubescent abaxially; buds linear, often falciform, apex acute, base bulbous. Sepals somewhat spreading at anthesis, 1/4–2/5-connate, 2.0–3.0 mm long, 2.3–4.5 mm wide, coriaceous, broadly triangular to semicircular, apex acute to obtuse, pubescent abaxially. Petals creamy yellow, greenish yellow, or dull yellow in vivo; outer petals spreading to recurved at anthesis, 17.2–33.5 mm long, 3.4–3.9 mm wide at base, 1.0–1.7 mm wide at midpoint, coriaceous, linear, often somewhat falcate, apex acute to obtuse, keeled on abaxial surface, gray-puberulent adaxially, yellow-brown sericeous abaxially; inner petals spreading to recurved at anthesis, 12.8–24.6 mm long, 2.1–3.0 mm wide at base, 0.6–1.0 mm wide at midpoint, coriaceous, linear, apex acute, base with undifferentiated margin, longitudinally ridged on both surfaces, densely puberulent on both surfaces except for glabrous base. Stamens 160–200; fertile stamens 1.1–1.6 mm long, narrowly oblong to clavate, apex of connective 0.1–0.3 mm long, shieldlike, overhanging anther thecae, glabrous or minutely papillate, anthers 9–12-locellate, filament 0.3–0.5 mm long; outer staminodes 1.6–1.8 mm long, quadrate or broadly clavate, apex obtuse to truncate; inner staminodes 0.9 mm long, broadly clavate, apex truncate; staminal cone 1.7–2.4 mm in diameter, 1.0–1.4 mm high, completely concealing the ovaries, rim even. Carpels 7–10; ovaries ca. 0.8 mm long, stigmas more or less connivent, 2.5–2.6 mm long, linear, apices acute, with a tuft of yellow to rusty hairs. Torus slightly concave beneath the ovaries, otherwise flat, 1.9–2.8 mm in diameter. Fruit of up to 7 glabrate monocarps borne on a pedicel 7–8 mm long, 1.9–2.5 mm thick, sparsely pubescent; torus of fruit ca. 3 mm in diameter, ca. 2.5 mm high, ovoid to globose. Monocarps with green to red exterior in vivo, endocarp color unknown, 1.8–2.6 cm long, 1.0–1.3 cm wide, ca. 0.8 cm thick, oblong, sometimes weakly torulose, apex obtuse with a short beak 1–2 mm long, base subsessile or contracted into a stipe 2.5–7 mm long, 2.5 mm thick, strongly rugose, occasionally pruinose; pericarp 0.2–0.4 mm thick. Seeds up to 4 per monocarp, in a single row, lying oblique to perpendicular to long axis, 10.3–12.2 mm long, 6.7–7.7 mm wide, 5.1–6.1 mm thick, ellipsoid, semicircular in cross-section, narrowed and truncate at micropylar end, rounded at chalazal end, brown, smooth, dull, raphe/antiraphe not evident, micropylar scar 1.5 mm long, 1.0–1.5 mm wide; sarcotesta red in vivo; aril absent.

Phenology

Specimens with flowers have been collected from January to May and those with fruits from December to February.

Distribution

(Fig. 26). Southern Angola and northeastern Namibia, east to western Zambia and south to northern Botswana and west-central Zimbabwe; most frequently reported from woodlands on Kalahari sands dominated by Baikiaea plurijuga (mukusi, Rhodesian teak), occasionally in miombo woodland dominated by Brachystegia spiciformis, or occasionally from the edges of riverbanks; 900–2000 m.

Local names

Mtjibi wenduna (Sindebele, Goldsmith 51/56), omuriandele (Antunes & Dekindt 3142), setundewanga (Sik, Pardy 4805), situndu bawanga (Lozi, White 2062), situnduboanga (Barotze, Jenkins 1), situndubwanga (“Bantu,” McFerren 30), umtshibi omduna (Ndebele, Mashasha 169). On the label of White 2062, it is explained that the name situndu bawanga is translated as “That which cannot be left,” attesting to the medicinal properties attributed to the plant by local people.

Additional specimens examined

ANGOLA. Huíla, clairieres de la montagne de Lopolo, 1800 m, Dec 1900 (fr), Antunes & Dekindt 3142 (P–3 sheets); Huíla, Polygonal Florestal da Humpata, ca. 5 km NE of Humpata, ca. 8 km SW of Lubongo, 14°58'54.9"S, 13°26'01.6"E, 2018 m, 26 Jan 2009 (fl), Bester 9279 (MO); Humber A bords du Cunene, Tyipelongo-Mucope-Danguena, 1910–1920 (fl, fr), Bonnefousc & Villain 92°2 (P); at Kubango near the forte Princeza Amelia, s. d. (fl), Gossweiler 3940 (BM, K); Bié, Kubango, 1905 (fr), Gossweiler 4043 (BM); Huíla, Mannyino, 1760 m, Jan 1901 (fl), Herbar. Huíla 276 (A); Huíla [or Bié], Ganguelas, Vila Artur de Paiva, margens do Cubango, 1450 m, 12 Jan 1960 (fl), Mendes 2086 (MO); Huíla, Huíla, próx. da M. Catolica do Mennhino, 6 Feb 1955 (fl), Santos 92 (MO, WAG); Huíla, Quilengues, Lucondo, ca. 1500 m, 28 Oct 1959 (st), Teixeira & Andrade 358 (PRE); Huíla, prope Lopolo, Jan 1860 (fr), Welwitsch 92 (BM). NAMIBIA. Eastern Caprivi, Katima Mulilo District, Katima Mulilo, 17 Feb 1971 (fl), Breitenbach 1312 (PRE); Kavango Andara at camp of Dept. Agriculture, Grid Ref. 1821 AB, 10 Feb 1958 (fl), Hilbert 158 (K); Eastern Caprivi, Katima Mulilo District, Katima Mulilo, 11 Feb 1968 (fl), McFerren 30 (PRE); Andara, R. C. Miss. Station, on Island near camp on bank of river, 24 Apr 1977 (fl), Müller & Giess 533 (PRE); Okavango Territory, Andara Camp, Okavango River banks, 18 Mar 1966 (fl), Tinley 1414 (PRE, WAG); O Caprivi, Katima Mulilo, 30 Jan 1975 (fl), Vahrmeijer & du Preez 2508 (PRE). ZAMBIA. Southern: Livingstone District, Livingstone, 12 Feb 1956 (fl), Gilges 586 (K, PRE); Livingstone, 12 Feb 1930 (fl), Jenkins 1 (BM); Livingstone, 22 Feb 1963 (fl), Lawton 1041 (K).—Western: Mongu District, Makapaela Pan, 25 km N of Mongu, 15°02'S, 23°14'E, 1020 m, 15 Feb 1999 (fl, Bingham & Luwiika 11893 (K); Mongu District, Kataba local forest, 20 km [“mm”] SE of Mongu, 15°27'S, 23°16'E, 1030 m, 16 Feb 1999 (fr), Bingham & Luwiika 11905 (K); Shisheke District 103 km SE of Senanga on road to Sesheke, 1050 m, 1 Feb 1975 (fl), Brummitt et al. 14224 (EA, MO, RSA, WAG); Kalabo District [“Barotse Province”], near Kalabo Boma, 13 Feb 1952 (fl), White 2062 (BM, K); Kalabo District, 5.6 km W of Kama Health Center, 5.5 km E of Lukona Secondary School in Kalamaba L. F. No. 379, 15°22'36.9"S, 22°53'44.5"E, 930 m, 21 Mar 1996 (fl), Zimba et al. 829 (MO, PRE).—Province unknown: Baikiaea forest region, Kalahari sand, S. N. Western Rhodesia, 1937 (st), Martin 786 (BM). BOTSWANA. Kazungula, Apr 1936 (fl), Miller B 132 (BM). ZIMBABWE. Wankie District, Fuller Forest Reserve, Mar 1960 (fl), Armitage 102/60 (MO); Victoria Falls, 10–15 Mar 1932 (fl), Brain 8875 (K, MO); Shangani/Bubi District, Gwampa Forest Reserve, 3000 ft, Feb 1956 (fl), Goldsmith 51/56 (K, PRE); Wankie District, Victoria Falls National Park, 14 Feb 1980 (fl), Kandanda 11 ([= s. n. at B?], MO); Wankie District, Victoria Falls village, 24 Jan 1979 (fl), Mshasha 169 (K, MO, WAG); Nyamanahlovu Dist., Jan 1929 (fr ped), Pardy 4502 (MO); Nyamanahlovu Dist., Jan 1931 (fl), Pardy 4805 (B, BM, K); Bulawayo, May 1898 (st), Rand 422 (BM).

Xylopia odoratissima is a shrub or spreading treelet with uniformly small leaves and with an inflorescence consisting of 1–3 flowers. The petals are long and often falcate at the apices, even in bud. The outer petals are widened abruptly at the base, such that the flower buds appear bulbous. The monocarps are reported to be red at maturity, and are prominently rugose when dried. Purple coloration at the bases of the inner petals is apparently absent (Fig. 3G). Xylopia odoratissima is a species restricted to the Baikiaea and Brachystegia woodlands on Kalahari sands from Angola to western Zimbabwe, where it occurs with Pseudolachnostylis and Parinari mobola as associates. It seems not to occur north or east of the Zambezi River, where it is replaced by Xylopia shirensis, which, while similar, can grow to be a tree up to 14 m tall and has larger leaves that are more variable in shape. The petals of X. shirensis are shorter and seldom falcate, and the inner petals have purple coloration at the base. The outer petals narrow gradually, and the widening of the base of the buds is therefore gradual as well. The monocarps are reported to be green at maturity, and are smooth or at most weakly wrinkled when dried.

Collectors frequently remark on the fragrance of the flowers. Welwitsch (as translated by Hiern 1896) wrote “flowers very fragrant, exceeded in the pleasantness of the aroma only by the species of Schrebera but their fragrance is far more intense.” The label of Jenkins 1, from southern Zambia, states “scent much resembling a sweet pea. Only noticeable after sunset. Then the tree → v. fragrant.”

Typification of names based on Welwitsch collections is problematic because Welwitsch held his specimens privately, and they were not distributed to herbaria until after his death. As explained by Albuquerque et al. (2009), the bulk of the collection was returned to LISU during the period 1876 to 1879. The second-best set remained at BM, and duplicates were distributed from LISU to other herbaria later on.

In this particular case, Welwitsch must have shown his collections to Daniel Oliver for use in preparing the first volume of the Flora of Tropical Africa, published in 1868, that is, while they were still in Welwitsch’s private collection and had not been divided up into sets. Oliver’s protologue gives a detailed description of the plant, in particular of the flowers. The fruits are described briefly and the seeds not at all. One of the specimens with flowers therefore seems to be the most appropriate choice as a lectotype.

According to Hiern (1896), Xylopia odoratissima was found by Welwitsch in flower in December of 1859 and in January and February of 1860. Welwitsch numbered his collections as he curated them, grouping together all collections thought to represent the same species under the same collection number (Albuquerque et al. 2009). All of the collections seem to have come from the same locality, so the only piece of information that can separate them is the date. Unfortunately, most of the duplicates seen lack a specific date.

A branch with flowers in the lower half of sheet 000511059 at BM is chosen as the lectotype. It is accompanied by a handwritten label that specifies Lopollo Dec. 1859. Photographs of this specimen have been distributed to a number of herbaria. In the absence of information about the date of collection, however, other specimens with flowers are not considered isolectotypes, although with better information, they may be identifiable as such in the future. For example, some of the specimens with flowers have leaves that have dried a darker color than those of the BM specimen. A specimen at LISU, which we viewed through JSTOR Global Plants, has been annotated as the “holotype,” but it cannot be so, given that the original description was based upon multiple gatherings. In addition, the date given on the specimen is April 1860, which does not accord with the flowering times for the species given in Hiern (1896), and we cannot see the specimen well enough to tell if it has flowers or fruits on it. For the record, we have seen Welwitsch 757 specimens from B (single sheet, flowering specimen, printed ticket without date, only information written on the label is 757 Xylopia odoratissima Welw.), BM (non-lectotype material on sheet 000511059), C (two sheets, seen via JSTOR), G (single sheet, specimen with flowers but leaves are darker than on BM sheet), K, LD, LISU (2 sheets), M, P (2 sheets, one ex herb. Pierre), and PRE.

The syntype Smith s. n., from the Congo River, is Xylopia longipetala and does not seem to have contributed significantly, if at all, to the protologue of Xylopia odoratissima and is therefore excluded as a possible lectotype.

Xylopia shirensis (Engler & Diels) D. M. Johnson & N. A. Murray, comb. nov.

Fig. 27M–P

Xylopia antunesii var. shirensis Engler & Diels, Monogr. afrik. Pflanzen-Fam. 6: 66. 1901. Type. MALAWI. Southern Region, Shiri Highlands [“Shire Hochland”], Chnambola, comm. 1881, J. Buchanan 237 (holotype: K!).

Description

Shrub or a tree up to 14 m tall, d.b.h. up to 20 cm; bark cracking. Twigs brown to dark brown, initially tomentose, the hairs 0.3–1.2 mm long, becoming light brown to gray or dark gray-brown, glabrate or with pubescence somewhat persistent; nodes occasionally with two axillary branches. Leaf with larger blades 4.5–10.2 cm long, 2.1–5.1 cm wide, chartaceous to subcoriaceous, concolorous or slightly discolorous, elliptic, oblong, or ovate, rarely oblanceolate, apex broadly acute, obtuse, or rounded, rarely nearly truncate or emarginate, base broadly cuneate to rounded, occasionally truncate or subcordate, sparsely pubescent on both surfaces; midrib slightly raised to plane adaxially, raised abaxially, secondary veins irregularly brochidodromous, 7–15 per side, diverging at 45–70° from the midrib, these and higher-order veins slightly raised on both surfaces; petiole 3.5–11 mm long, shallowly canaliculate or somewhat flattened, pubescent. Inflorescences axillary or from axils of fallen leaves, 1–6-flowered, pedicels emerging side by side from axil or rarely from a common peduncle, pubescent; peduncle ca. 3.5 mm long, with 2 pedicels per peduncle; pedicels 2.8–7 mm long, 1.2–1.5 mm thick; bracts 2, at or proximal to midpoint, caducous or somewhat persistent, lower 1.9–2.6 mm long, upper 1–1.7 mm long, semicircular to ovate, apex obtuse or rounded; buds lanceolate, apex more or less acute. Sepals slightly spreading at anthesis, 1/4–1/2-connate, 1.5–3.0 mm long, 2.3–3.4 mm wide, chartaceous to coriaceous, triangular, broadly ovate, or semicircular, apex acute, pubescent abaxially. Petals yellow-green to pale yellow, the inner petals crimson or purple-tinged on the inner base in vivo; outer petals spreading at anthesis, 12.2–20.9 mm long, 2.3–3.3 mm wide at base, 1.0–1.6 mm wide at midpoint, coriaceous, linear-lanceolate, apex obtuse, densely pubescent on both surfaces, the pubescence more yellowish abaxially; inner petals spreading to weakly geniculate at anthesis, 9.3–14.6 (–21.5) mm long, (1.6–) 2.0–2.9 mm wide at base, 0.5–1.0 mm wide at midpoint, coriaceous, linear-subulate, apex obtuse, base with undifferentiated margin, densely gray-puberulent on both surfaces, except for glabrous base. Stamens ca. 120; fertile stamens 1.0–1.2 mm long, narrowly oblong, apex of connective 0.1–0.2 mm long, shieldlike, overhanging anther thecae, glabrous, anthers 8–11-locellate, filament 0.3–0.5 mm long; outer staminodes 1.2–1.4 mm long, clavate to oblong, apex obtuse, rounded, or truncate; inner staminodes ca. 0.8 mm long, rectangular, apex truncate; staminal cone 1.2–2.3 mm in diameter, 0.8–1.1 mm high, concealing only the bases of the ovaries, rim laciniate. Carpels ca. 7; ovaries ca. 1 mm long, narrowly oblong, pubescent, stigmas loosely connivent, 2–2.6 mm long, linear, glabrous except for a tuft of hairs at the apex. Torus concave beneath ovaries but otherwise flat, 2.0–3.7 mm in diameter. Fruit of up to 8 glabrate monocarps borne on a pedicel 5.5–10 mm long, 1.9–2.5 mm thick, pubescent to glabrate; torus 3.3–5 mm in diameter, 2–3.0 mm high, staminal cone often persistent on it, depressed-globose. Monocarps with pale green to purple-red exterior and green endocarp in vivo, 1.2–3.8 cm long, 1.0–1.2 cm wide, 0.8–1.1 cm thick, oblong, irregularly torulose, apex rounded or obliquely truncate, occasionally with a short beak ca. 1 mm long, base contracted into a stipe 3.5–9 mm long, 2–3 mm thick, slightly obliquely wrinkled, finely verrucose, occasionally pruinose; pericarp 0.2–0.3 mm thick. Seeds 1–6 per monocarp, in a single row or two irregular rows, oblique to long axis, 8.5–11 mm long, 6.0–8.3 mm wide, 5.1–6.5 mm thick, ellipsoid, broadly elliptic in cross-section, brown, slightly wrinkled, dull, micropylar end truncate, chalazal end rounded, raphe/antiraphe not evident, micropylar scar ca. 2.5 mm long, elliptic; sarcotesta deep orange in vivo; aril absent.

Phenology

Specimens with flowers have been collected from October to February, and with fruits in October and from December to February.

Distribution

(Fig. 26). Occurs from southern Democratic Republic of the Congo east to western Tanzania and south to eastern Zambia and Malawi in open woodland, often dominated by Brachystegia spp. and often on sand, at elevations of 470–1770 m.

Local names

Akiziga (Kilungu, Bredo 6276), chikiza or kikiza (Chimambwe (Musa) and Chilungu), Michelmore 1045), kizika (Kikungu, Bredo 6232), mshenene (Kinyamezi, Wigg F.H. 1121), msyenene (Kinyamwezi, Shabani for Bullock 10), mtuzya (Kinyamwezi, Mwiga et al. 174).

Additional specimens examined

DEMOCRATIC REPUBLIC OF THE CONGO. Haut-Katanga: Kisanga [near Lubumbashi], 1200 m, 20 Jan 1984 (fl), Malaisse 13134 (MO, WAG); prés de Mulwe forêt Katanguaise, 7 Jan 1949 (fl), de Witte 5144 (K, P). TANZANIA. Iringa: Iringa District, 44 km on Mafinga-Madabira road, 08°14'S, 34°58'E, 1300 m, 26 Mar 2006 (fl), Bidgood et al. 5122 (K, MO).—Kigoma: Bangwe, Kigoma District, Western Province, T. T., 2450 ft, Nov 1956 (buds), Procter 558 (NHT).—Mbeya: T7, Mbeya District, above Chimala Mission, 8°50'S, 34°01'E, 1200 m, 23 Mar 1988 (fl), Bidgood et al. 642 (K, NHT, WAG); Madibira, 1200 m, 28 Jan 2001 (fr), Congdon 588 (K).—Shinyanga: Kahama, 18 mi along Ushirombo R., 1 Jan 1936 (fl), Burtt 5459 (BM, K).—Tabora: Tabora, 28 May 1970, Collinson U.9 (EA); Tabora, s. d., Hammerstein 5838 (EA, K); S of Kuliwa—Tabora Region, 5°30'S, 32°40'E, 15 Nov 1979 (fl), Lawton 2178 (K, P); S Tabora, Lindeman 440 (K); Sikonge South Tabora, 29 Sep 1940 (yg fr), Lindeman 788 (K); Ulyakulu Forest Reserve, Tabora, Manolo 183 (K); Tabora, Tabora Rural District, Mtakuja Village, Urumwa Forest Reserve, 4°53'29"S, 32°45'25"E, 1040 m, 6 Jul 1999 (fl, yr fr), Mwiga et al. 174 (MO); collected from the Tabora Beekeeping Institute Plantation, 28 Nov 1976 (buds), Shabani 1131 (K, WAG); without definite locality [probably Tabora], Wigg 523 (MO, US); Simbo Reserve, Tabora, June 1938 (st), Wigg F.H.1121 (K). ZAMBIA. Eastern: Ndundu Hill, 1770 m, 5 Oct 1966 (fl), Richards 31484 (K); Chadiza, 850 m, 29 Nov 1958 (fr), Robson 770 (BM, K).—Luapula: Western Province, Fort Rosebery District, near Lake Bangweulu, Samfya Mission, 24 Aug 1952 (fr), Angus 304 (BM, K, MO); Western Province, Fort Rosebery District, near Lake Bangweulu, Samfya Mission, 28 Aug 1952 (old fls), White 3156 (K).—Northern: Abercorn, 10 Nov 1948 (st), Bredo 6232 (BR); Abercorn District, Ulungu County, Mchinda village, 13 Nov 1948 (fr), Bredo 6276 (BR); Kawimbe, 11 Nov 1949 (fl), Bullock 1414A (K, P); Mutinondo Wilderness, Mpika, 1500 m, 24 Dec 2005 (fr), Congdon 709 (K); Abercorn District, 4500’, Feb 1932 (fl), Gamwell 106 (BM); NE of Abercorn, 11 Dec 1934 (fl), Michelmore 1045 (EA, K); Abercorn, 1933, Miller 133D (A, BM, K); Abercorn District, Chilongowelo, in open ground close to Plain of Death, 4800 ft, 29 Sep 1954 (fl), Richards 1881 (K); Abercorn District, close to Lucheche stream by road to Abercorn Club turning, 5000 ft., 23 Feb 1954 (fl), Richards 2326 (K); Abercorn District, Kawimbe, 1680 m, 2 Jan 1956 (fl, fr), Richards 6833 (K); Abercorn District, Kawimbe, 1740 m, 20 Sep 1960 (buds, fr), Richards 13266 (K); Uninji Pond, Mbala, 5000 ft, 3 Nov 1968 (fl), Sanane 346 (B, K); Northern Province, Abercorn District, near top of Sunzu Hill, 18 Nov 1952 (fl), White 3711 (K, MO). MALAWI. Machinga District, Chikala Mt. Liwonde Forest Reserve, Grid Ref. 36LYU6927, 1460 m, 30 Feb 1982 (fl), Patel 977 (K); Machinga District, Chikala Mt. Liwonde Forest Reserve, Grid Ref. 36LYU6927, 1460 m, 5 Dec 1982 (fl), Patel & Tawakali 1028 (K); N Region, Karonga District, Vinthukutu Forest Reserve, 10 Jan 1990 (fl), Patel & Usi 4605 (PRE); N. Prov., Nkhata Bay District, Nkhata Bay, Chikale Beach, 1550 ft., 5 Dec 1976 (fl), Pawek 11992 (MO, WAG; N. Prov., Chitipa District, Kaseye Mission, 10 mi E of Chitipa, 1270 m, 26 Dec 1977 (fl, fr), Pawek 13379 (K, MO, WAG); N. Prov., Mzimba District, 5 mi. NE of Mzambazi, 22 Jan 1978 (fr), Pawek 13659 (K, MO, WAG); N. Prov., Mzimba District, 5 mi. NE of Mzambazi, 22 Jan 1978 (fl), Pawek 13660 (MO); Nkata District, Chinteche nr. Sand Dunes, L. Nyasa, 570 m, 21 Feb 1961 (fl), Richards 14438 (K); Central Province, Senga Bay Hotel, nr. Salima, 470 m, 16 Feb 1959 (fl), Robson & Steele 1628 (BM, K, PRE).

Xylopia shirensis includes specimens formerly identified as Xylopia odoratissima in Boutique (1951b), Robson (1960), and Verdcourt (1971b), but it differs consistently from that species in the somewhat longer and wider leaves, up to 10.2 cm long and 5.1 cm wide versus 6.9 cm long and 3.3 cm wide, more variable size and shape of the leaves, the smaller flowers that are grouped into inflorescences of 1–6 flowers, flower buds less bulbous at the base, and petals marked with red or purple on the inner base. The two species are not known to overlap in distribution, although both occur frequently in Brachystegia woodland.

The label of Congdon 588 from western Tanzania notes that the plant is a food plant for the larvae of the Abantis butterfly; Cock and Congdon (2011) report that this is one of a number of food plants from a variety of families that are used by Abantis paradisea (Butler). The Congdon specimen also includes a photograph of the dehisced monocarp, showing the green endocarp and orange sarcotesta that characterize the members of the X. odoratissima subgroup. Several specimens show an oblong gall-like structure developing within the androecium of the flower.

Xylopia tomentosa Exell, J. Bot. 64 Suppl.: 7. 1926.

Fig. 30

Xylopia odoratissima var. minor Engler, Monogr. afrik. Pflanzen-Fam. 6: 66. 1901. Type. ANGOLA. Cuando Cubango Province, “Kunene-Gebiet, Kuelleis (Maramba) auf weissem Sandboden am Waldrand unter hohen Houtboschbäumen [Grv. Kassinga n. d. Kubango], 1400 m, 5 Oct 1899, H. Baum 224 (holotype: B!; isotypes: BM! [000511042, left hand side of sheet], COI! [00004890], K! [001089662], M! [0107924]).

Xylopia mendoncae Exell, J. Bot. 72: 280. 1934. Type. ANGOLA. Lunda Province, Vila Henrique de Carvalho, 3 Sep 1927, L. W. Carrisso & F. de A. Mendonça 506 (holotype: BM! [000511043, photos at GH, NY]; isotypes: COI! [00004889, ? as “506A”, FI-T! M! [0107920, ? as “506A”], MO! [1599594]).

Type

ANGOLA. Cuando Cubango Province, in the mosacollas up River Bunja, Cuito, 5 Feb 1906, J. Gossweiler 3564 (holotype: BM! [000511045, specimen in lower right of sheet]; COI! [00004893, photos at GH, NY], probable isotype [see below]: K!).

Description

Shrub or sub-shrub 0.4–4 m tall. Twigs dark brown to gray, longitudinally striate, tomentellous, the hairs 0.2–0.6 mm long, eventually brown to light gray, glabrate, occasionally with bark exfoliating; nodes with 2–3 axillary branches. Leaf with larger blades 2.5–6.6 cm long, 1.3–3.8 (–4.2) cm wide, subcoriaceous or chartaceous, discolorous, often purplish adaxially and yellow-tan abaxially, elliptic, oblong, or oblong-lanceolate, less frequently lanceolate or ovate, apex rounded or obtuse, base broadly cuneate, truncate, or subcordate, sparsely pubescent on both surfaces, at length glabrate adaxially but persistently pubescent abaxially; midrib plane to slightly raised adaxially, raised abaxially, secondary veins indistinctly brochidodromous, 6–12 per side, diverging at 45–80° from the midrib, these and higher order veins usually forming a raised reticulum on both surfaces but sometimes indistinct; petiole 1.5–5.5 mm long, shallowly canaliculate, tomentellous. Inflorescences axillary, 1–8-flowered, densely pubescent; peduncles 1 per axil, 1 mm long, or absent; pedicels up to 3 per peduncle, 0.4–2.3 (–5.5) mm long, 0.7–0.9 mm thick; bracts 2–3, congested on pedicel, persistent or caducous, 2.2–2.9 mm long, ovate to broadly ovate, often bilobed, apex obtuse; buds lanceolate, apex obtuse. Sepals spreading at anthesis, 1/5–1/3-connate, 1.8–3.0 mm long, 2.0–3.7 mm wide, coriaceous, ovate to broadly ovate, apex acute to obtuse, pubescent abaxially. Petals cream-colored to light yellow with brown pubescence in vivo; outer petals erect at anthesis, 7.4–12.9 (–18.5) mm long, 2.2–2.9 (–3.4) mm wide at base, 1.3–2.0 mm wide at midpoint, fleshy, lanceolate, apex acute, densely puberulent on both surfaces except for a glabrous patch at base adaxially; inner petals geniculate at anthesis, with the apices bent sharply outward between the outer petals, 5.1–8.9 (–12.5) mm long, 1.4–2.6 mm wide at base, 0.6–1.0 mm wide at midpoint, fleshy, lanceolate, apex long-acuminate, base with undifferentiated margin, puberulent except for glabrous base adaxially, puberulent on narrowed apex and medial portion of base abaxially, otherwise glabrous. Stamens ca. 100; fertile stamens 1–1.3 mm long, narrowly oblong or clavate, apex of connective 0.2–0.3 mm long, shieldlike or slightly hemispheric, overhanging the anther thecae, papillate, anthers 10–14-locellate, filament 0.3–0.4 mm long; outer staminodes 1.0–1.4 mm long, broadly clavate, apex rounded to truncate; inner staminodes ca. 0.9 mm long, clavate, apex truncate; staminal cone 1.0–1.4 mm in diameter, ca. 0.7 mm high, concealing only the bases of the ovaries, rim laciniate. Carpels 5–6; ovaries 0.9–1.4 mm long, oblong, pubescent, stigmas connivent, 1.4–2.4 mm long, linear, setose toward apex. Torus flat, 1.3–1.8 mm in diameter. Fruit of up to 11 brown-tomentose monocarps borne on a pedicel 4–8 mm long, 1.2–3.2 mm thick, pubescent to glabrate, with bracts and sepals sometimes persistent; torus 2.5–6.8 mm in diameter, 2.9–6.3 mm high, globose. Monocarps with green exterior and red to pink endocarp in vivo, 1.6–3.3 cm long, 0.9–1.3 cm wide, 0.8–1.4 cm thick, oblong, obliquely torulose, apex obtuse, occasionally with a broad oblique beak ca. 0.4 mm long, base contracted into a stipe 2–8 mm long, 1.8–2.8 mm thick, obliquely wrinkled; pericarp 0.4–0.6 mm thick. Seeds 1–3 per monocarp, in a single row, oblique to long axis, 6.8–9.4 mm long, 4.9–7 mm wide, 4–6 mm thick, ellipsoid to ellipsoid-pyriform and then narrowed into a cylindrical neck 1.5–2 mm long and 2.2–4.6 mm wide toward micropyle, elliptic in cross section, truncate at micropylar end, rounded at chalazal end, brown, smooth, glossy, raphe/antiraphe not evident, micropylar scar 1.3–1.8 mm long, 1.0–1.2 mm wide, elliptic to ovate; sarcotesta orange to red, fleshy in vivo; aril absent.

Figure 30. 

Xylopia tomentosa. A Close-up of abaxial surface of leaf B–D Leaves to show range of variation E, F Inflorescences G Fruit H Close-up of monocarp surface, showing pubescence I Seed, micropylar view J Seed, side view K Outer petal, adaxial view L Inner petal, adaxial view M Receptacle, with sepals, some stamens, and ovaries still attached N Stamen, abaxial view O Outer staminode, abaxial view. A, D based on Brummitt et al. 14111 (K) B, G, H from Exell & Mendonça 374 (BM) C from Brummitt et al. 14068 (MO) E from Milne-Redhead 2528 (K) F, K, L, N, O from Holmes 1056 (K) I, J from Brummitt et al. 14068 (K) M from Pocock 445 (A).

Phenology

Specimens with flowers have been collected from December to June and in September and October, and with fruits in every month of the year except September.

Distribution

(Fig. 22). Occurs from southern and southwestern Democratic Republic of Congo east to northeastern Zambia and south to northeastern Namibia and southwestern Zambia. Xylopia tomentosa grows in thickets or sub-xerophilic forest on sandy or otherwise siliceous soils with species of Cryptosepalum (mavunda), Copaifera, Psorospermum, Baphia, Brachystegia (mucuwe), Burkea, Uapaca, and Swartzia, at elevations of 1000–2000 m.

Local names

Changue (Wemba, Brenan & Greenway 8041), itundubywangu (Rea 119), mujimbajimba (Chiokwe, Exell & Mendonça 1310), mulamo (Chikaonde, Milne-Redhead 951), mundzeemba dzeemba (Pocock 445), situndu bawanga (Lozi, White 2071, 2079).

Additional specimens examined

DEMOCRATIC REPUBLIC OF THE CONGO. Haut-Katanga: 120 km S de Mukulakulu (gare près de Luéna) [9°33'S, 25°47'E], sur la route vers Kanzenze et Kolwezi, 5 Nov 1958 (fr), Schmitz 6188 (BR).—Kwango: environs de Kitenda [6.8°S, 17.35°E], 15 Feb 1950 (fr), Callens 2440 (BM); Prov. Leopoldville, Kasongo Lunda, Kibunda [7°29'S, 18°12'E], 4 Feb 1952 (bud, fr), Callens 3056 (BM, K); Kimbuba [5°45'S, 15°49'E], 28 Dec 1952 (fr), Callens 3850 (EA); Kimbuba, 29 Dec 1952 (fl), Callens 3859 (B); Pansi, Aug 1950 (fl), Callens 2730 (BM); Prov. Léopoldville, Territ. Kasongo-Lunda, Kibunda, 26 Apr 1953 (fr), Callens 3983 (BM, WAG); Mikondo, Kahemba, 11 Mar 1954 (buds), Devred 1420 (K); Prov. Leopoldville, Territ Kahemba, Kahemba-Kwango, 28 Apr 1955 (fr), Devred 1824 (K); de Mto Mbombo á Kinlongo, Terr. Popokabaka, 9 Jan 1959 (st), Pauwels 1242 (BR); Kimbuba, Terr. Popokabaka, 12 May 1959 (fr), Pauwels 2961 (BR); Kimbuba, Terr. Popokabaka, 12 May 1959 (st), Pauwels 2972 (BR). ANGOLA. Benguela: Cubal, entre Caimbambo e o Cubal, a 8 kms de Caimbambo, 20 Jul 1969 (buds), Barbosa 11754 (MO).—Bié: Munhango, 27 Jan 1940 (fl, fr), Andrada 51 (MO, WAG); Munhango, Mar 1943 (fr), Andrada 51A (MO).—Cuando Cubango: Environ à 10 km à l’Est de Longa, 14°49'S, 18°38'E, Dechamps et al. 1324 (YF), 2 Mar 1974 (fl), Dechamps et al. 1325 (K, WAG, YF), 2 Mar 1974 (fl), Dechamps et al. 1330 (MO, YF); Kubango, 2 Oct 1905 (bud, fr), Gossweiler 2054 (BM, K); Kubango region, between the rivers Cdui and Tunga, 15 Oct 1905 (fr), Gossweiler 2102 (BM); between Cuiriri and Cuito, 1906 (fl), Gossweiler 2562 (BM, K); at T’chirandangambe river Luassingua-Ganguellas, s. d. (fr), Gossweiler 3463 (BM [on same sheet with Gossweiler 3564], K); between rivers Kuito and Kuiriri, Jan 1906 (fr), Gossweiler 3464 (BM); nr. Cassuango, Cuiriri, Jan 1906 (fl), Gossweiler 3465 (BM—2 sheets [one on same sheet as Baum 224, other on same sheet as Gossweiler 3567], K); Bunja nascente Cuito, 5 Feb 1906 (fl, fr), Gossweiler 3567 (BM); at Kassuango near Kuiriri, 24 Mar 1906 (fl), Gossweiler 3672 (BM, K); Kassuango Kuiriri, Mar 1906 (fl), Gossweiler 3733 (BM, K); in the valley of River Kuiriri, 1906 (fr), Gossweiler 4044 (BM); R. Kutri, also at R. Kunzambia, 27 Jun 1925 (fl, fr), Pocock 445 (A).—Huambo: between Bimbe and Sanga, near Bimbe [15°12'S, 17°41'E], 1300–1700 m, 24 Jun 1937 (fl), Exell & Mendonça 3063 (BM, MO); Benguella, country of the Ganguellas and the Ambuellas, rec’d 1910, Gossweiler s. n. (K).—Huíla: Between Sá da Bandeira and Humpata, 16 May 1937 (fl), Exell & Mendonça 2030 (BM, M, MO).—Lunda: Xá-Sengue [10°27'S, 20°13'E], 7 Apr 1937 (fl), Exell & Mendonça 370 (BM, M, MO), Xa-Sengue, ca. 1200 m, 7 Apr 1937 (fr), Exell & Mendonça 374 (BM, MO); R. Luachimo, between Vila Henrique de Carvalho and Dala, ca. 1300 m (fl), 24 Apr 1937 (fl), Exell & Mendonça 1024 (BM); entre Vila Henrique de Carvalho e Dala, 24 Apr 1937 (fl, fr), Exell & Mendonça 1055 (BM, M, MO); between Vila Henrique de Carvalho and Dala, 1100–1300 m, 24 Apr 1937 (fr), Exell & Mendonça 1064 (BM); Dala, 1200–1230 m, 23 Apr 1937 (fl, fr), Exell & Mendonça 1101 (BM, M, MO), Dala, 1200–1230 m, 25 Apr 1937 (fr), Exell & Mendonça 1102 (BM, M); Biula [11°11'S, 20°13'E], R. Chicoso, c. 1200 m, 27 Apr 1937 (fr), Exell & Mendonça 1310 (BM); Dala, ca. 1230 m, 29 Apr 1937 (fr), Exell & Mendonça 1430 (BM, MO); Dala, ca. 1230 m, 29 Apr 1937 (fr), Exell & Mendonça 1431 (BM); Dala, próx. do rio Chimbe, Apr 1937 (fl, fr), Gossweiler 11202 (BM, M, MO); Mona Quimbundo, proximum flumen Luvo, 1000 m, Apr 1937 (fl), Gossweiler 11833 (BM); Missão de Luz, 29 Dec 1933 (fl), Lynes 351a (BM); Ma-chinga and Ma-Lunda, Jun 1885 (fr), Marques 165 (BM); Saurimo-Dala, 1 Nov 1932 (fl), Young 1306 (A, BM).—Moxico: Between Vila Luso and R. Cassai, 4 May 1937 (fl), Exell & Mendonça 1632 (BM); entre Cachipaque e Munhango, 7 May 1937 (fl), Exell & Mendonça 1790 (BM, M, MO); Teixeira de Souza, 9 Jul 1940 (fl), Gossweiler 12340 (BM). NAMIBIA. Bei Bikundu, 19 km südlich Andara, 12 Jun 1971 (fl), Giess 11354 (M—2 sheets, WAG—2 sheets); Okavango Native Territory, border clearance 1 m W of Katwitwi [17°24'S, 18°25'E], de Winter 3845 (K, M); Okavango Native Territory, 3 mi. S of Omuramba Mpungu [17.8°S, 18.9°E] on rd. to Tsinaabia, de Winter 3879 (K, M). ZAMBIA. Luapula: Fort Rosebery, on low fixed dunes by shore of L. Bangweolo, a short way N of Samfya Mission, 6 Oct 1947 (fl), Brenan & Greenway 8041 (BM, EA, K—2 sheets), 6 Oct 1947 (fr), Brenan & Greenway 8044 (EA, K).—Northwestern: Mwinilunga District, near Zambezi R. 4 mi N of Kalene Hill Mission, 23 Sep 1952 (fl), Angus 529 (K, MO); Solwezi District, proposed transmission line clearing near Kabompo R. crossing point, Chipawa, 12°13'S, 25°11'12"E, 1154 m, 30 Apr 2012 (fl), Bingham 14167 (K); Mwinilunga District, 28 km on Matonchi road, 11°44'S, 24°14'E, 24 Jan 1975 (fr), Brummitt et al. 14068 (K, MO); Mwinilunga District, 60 km S of Mwinilunga on road to Kabompo, Brummitt et al. 14111 (K, WAG); Samfya, 3 Oct 1953 (fr), Fanshawe F.390 (K); Balovale [Zambezi], Lukolwe [13°33'S, 23°07'E], 9 Aug 1952 (fr), Gilges 156 (K); Balovale District, about 10 miles S of Chavuma [13°04'S, 22°41'E], 1–10 Feb 1953 (fl), Holmes 1056 (K); Mwinilunga District, between Mukimina and Kahuku, 24 Aug 1930 (fr), Milne-Redhead 951 (K); Mwinilunga District, just N of Mwinilunga, 2 Oct 1937 (fl), Milne-Redhead 2528 (B, K–2 sheets); Mwinilunga District, just S of Matonchi farm, 30 Dec 1937 (fr), Milne-Redhead 3887 (K); Zambia, K. Gorge, Solwezi, 15 May 1969 (fl), Mutimushi JMM 3325 (K); Kabompo District, Manyinga, ca. 30 km from Loloma Hospital junction along the Kabompo-Mwinilunga Road, 13°17'47"S, 24°15'04"E, 1140 m, 9 Mar 1995 (fl), Nawa et al. 213 (MO); Mwinilunga District, 10 mi W of Kakoma, 30 Sep 1952 (fl), White 3436 (K).—Western: Mongu District, near Mongu, 21 Jul 1961 (fr), Angus 3010 (K, NY); Namushakende-Nalikwanda road, 24 km, 15°26'45"S, 23°25'48"E, 1000 m, 5 Jul 1997 (fl), Bingham et al. 11492 (K); Kaoma District, ca. 5 km along road to Luampa Hospital from intersection with Lusaka-Mongu Roads, 14°59'05"S, 24°32'14"E, 1080 m, 2 Mar 1996 (fl), Harder et al. 3644 (MO); Barotse Province, Senanga District, 18 Jun 1950 (fl), Rea 119 (K); Barotseland, Mongu District, 44 mi from Mongu along new main road east [15°25'S, 23°17'E], 21 Oct 1972 (fr), Strid 2370 (MO); Barotse Province, Kalabo District, Sikongo Forest Reserve, Kalabo to Sikongo, mile 7, 14 Feb 1952 (fl), White 2071 (K); Barotse Province, Kalabo District, Sikongo Forest Reserve, 15 Feb 1952 (st), White 2079 (K); Kaoma District, 51.3 km NW along Kaoma-Lukulu Road, from junction of Kaoma-Mungu Road, 14°35'40.9"S, 24°20'03.6"E, 1080 m, 1 Mar 1996 (fr), Zimba et al. 739 (MO).—Province unknown: S. N. W. Rhodesia, Baikiaea forest Region, 1937 (fl), Martin JDM 762 (BM).

By its shrubby habit, densely tomentose leaves, and congested inflorescences of up to eight small flowers, Xylopia tomentosa is readily distinguished from X. odoratissima, which may occur in some of the same habitats over its distribution. Several specimens (Baum 224, Exell & Mendonça 1790, Gossweiler 11202) have petals longer than is typical for X. tomentosa, the outer petals up to 18.5 mm long in the case of Gossweiler 11202, approximating the petal length of Xylopia odoratissima, but the pedicels are shorter and the outer petals taper gradually so that the width at the midpoint is greater (ca. 3.4 mm) than is found in X. odoratissima (1.0–1.7 mm wide). However, the sharply geniculate inner petals and pink endocarp of the fruits of X. tomentosa are more similar to X. arenaria, X. collina, and X. keniensis.

Xylopia tomentosa is variable in the number of flowers per inflorescence and size and shape of the leaves. Specimens with only one flower per leaf axil, for example Callens 3859 from the Democratic Republic of the Congo, can look very different from those with inflorescences with large numbers of flowers, for example the type specimen of Xylopia mendoncae, but all possible intermediates between these two extremes occur. Variation in leaf shape includes specimens with narrowly oblong leaves, such as the type of Xylopia odoratissima var. minor (Baum 224) and Dechamps et al. 1325, and nearly orbicular leaves (Gossweiler 3563). The label of one specimen described the plant as re-sprouting after fire, and it is possible that the variability in leaf morphology represents growth plasticity of regenerating vegetative shoots.

Numerous collectors remarked on the sweet-scented flowers, but nothing is known of flower visitors or floral biology.

A specimen of X. tomentosa at K is numbered Gossweiler 3563, but was annotated by A. W. Exell in 1926 with the comment “Gossweiler 3563 in Herb. Brit. Mus. is Vernonia potamophila Klatt, while our specimens of X. tomentosa are 3463 and 3564.” The K sheet contains a specimen with flowers and leaves similar in appearance to those on the Xylopia tomentosa holotype specimen Gossweiler 3564 at BM, and it seems probable that the K sheet is in fact an isotype of this name.

Xylopia torrei N. Robson, Bol. Soc. Brot., Sér. 2, 32: 157–158. 1958.

Fig. 25M–T

Type

MOZAMBIQUE. Gaza [“Sul do Save”] Province, Chibuto, 11 Dec 1940, A. R. Torre 2350 (holotype: LISC! [000361]; isotypes: K! [000199051], LMA—photo!).

Description

Shrub 2–3 m tall with spreading branches. Twigs brown to reddish brown, sparsely pubescent, the hairs 0.4–0.6 mm long, becoming light brown to light gray, glabrate, with the bark exfoliating; nodes occasionally with two axillary branches. Leaf with larger blades 3.8–5.5 cm long, 1.8–2.5 cm wide, chartaceous, concolorous, elliptic, apex obtuse or rounded, rarely emarginate, base broadly cuneate to rounded, glabrous or with a few scattered hairs adaxially, sparsely pubescent abaxially; midrib plane adaxially, raised abaxially, secondary veins weakly brochidodromous, 7–9 per side, diverging at 50–60° from the midrib, these and higher-order veins slightly raised on both surfaces; petiole 3–3.5 mm long, shallowly canaliculate, pubescent. Inflorescences axillary, 1–3-flowered, pubescent; pedicels arising separately from axil, 4.0–5.4 mm long, 0.5–0.9 mm thick; bracts 2, both attached near pedicel midpoint, caducous, 0.9–1.3 mm long, semicircular to ovate, apex obtuse to rounded; buds linear, apex acute. Sepals spreading at anthesis, 1/4–1/2-connate, 1.8–2.2 mm long, 2.1–2.3 mm wide, chartaceous to coriaceous, broadly ovate to semicircular, apex acute to apiculate, pubescent abaxially. Petals yellow-green in vivo; outer petals loosely spreading at anthesis, 20–30.4 mm long, 2.6–3.1 mm wide at base, 1.2–1.7 mm wide at midpoint, chartaceous, linear, apex acute to obtuse, densely puberulent except for glabrous base adaxially, appressed-pubescent abaxially, faintly ridged or flat abaxially; inner petals curved outward to weakly geniculate at anthesis, 23–28 mm long, 2.0–2.2 mm wide at base, 0.6–0.7 mm wide at midpoint, chartaceous, linear-filiform, apex acute, base with undifferentiated margins, longitudinally ridged on both surfaces, densely puberulent except for glabrous base adaxially, densely puberulent abaxially. Stamens ca. 100; fertile stamens 1.1–1.2 mm long, narrowly oblong, apex of anther connective red in vivo, shieldlike, overhanging anther thecae, anthers 9–10-locellate, filament 0.3–0.4 mm long; outer staminodes 1.1–1.3 mm long, clavate to broadly clavate, apex rounded to truncate; inner staminodes ca. 1.0 mm long, oblong-clavate, apex truncate; staminal cone ca. 1.4 mm in diameter, ca. 0.9 mm high, concealing only the bases of the ovaries, rim laciniate. Carpels ca. 7; ovaries 0.8–0.9 mm long, ovoid to oblong, pubescent; stigmas connivent, ca. 2.7 mm long, linear, glabrous except for an apical tuft of hairs. Torus flat, 1.6–2.2 mm in diameter. Fruit of up to 8 glabrate monocarps borne on a pedicel ca. 6.5 mm long, ca. 3.9 mm thick, glabrate; torus of fruit ca. 6.7 mm in diameter, ca. 6.3 mm high, depressed-globose. Monocarps green with a light green endocarp in vivo, 2.8–3.1 cm long, 1.0–1.1 cm wide, ca. 0.9 cm thick, oblong, irregularly torulose, apex truncate with an oblique beak 0.5–1 mm long, base contracted into a stipe 4.5–6 mm long, 1.8–2.7 mm thick, obliquely wrinkled, minutely verrucose; pericarp 0.2–0.5 mm thick. Seeds up to 4 per monocarp, in a single row, lying oblique to long axis, 10.5–11.5 mm long, ca. 7.5 mm wide, 6.1–6.7 mm thick, ellipsoid, flattened-elliptic in cross-section, obliquely truncate at micropylar end, rounded at chalazal end, brown, smooth, shiny, raphe/antiraphe not evident, micropylar scar 1.7–2.4 mm long, 1.1–1.4 mm wide, ovate to elliptic; sarcotesta red in vivo; aril absent.

Phenology

Specimens with flowers have been collected in February and December, and with fruits in December.

Distribution

(Fig. 26). Endemic to southern Mozambique, on sandy sites near the coast at elevations from sea level up to 60 m.

Additional specimens examined

MOZAMBIQUE. Gaza [“Sul do Save”]: Chibuto, 11 Feb 1942 (fl), Torre 3944 (LMA—2 sheets, photos).—Inhambane [“Sul do Save”]: Panda, 25 Feb 1955 (fl), Exell et al. 598 (BM).—Maputo: Licuati Forest Reserve ca. 20 km W of Bela Vista, 26°20.667'S, 32°28.387'E, 60 m, 8 Dec 2001 (fl, fr), Goyder et al. 5037 (K); Licuati, sand forest, 25°26'S, 32°30'E, 60 m, 5 Dec 2002 (fr), Lötter s. n. (LYD—photo).

Xylopia torrei superficially resembles X. odoratissima in its small leaves, long petals, and shrub habit. It may be distinguished by the straighter and sparser hairs of the twigs, the smaller sepals, and the outer petals narrower at the base. The tendency for exfoliation of the bark on the twigs may also be diagnostic. The species is only known from a small area in the southernmost part of Mozambique, where it appears to be restricted to coastal sand forest at low elevations, and has the southernmost distribution of any African Xylopia species, remote from the distribution of any other species. We calculated for it an EOO of 7,053 km2 and an AOO of 12 km2.

Xylopia toussaintii Boutique, Bull. Jard. Bot. État 21: 111–112. 1951.

Type

DEMOCRATIC REPUBLIC OF THE CONGO [“Belgian Congo”]. Kongo Central Province, Mayumbe, Luki, vallé de la N’kula, May 1948, L. Toussaint 373 (holotype: BR!; isotypes: BM! [000511058], BR! [0000008825483], K! [000199052], P! [00169123, 00169124]).

Description

Tree up to 30 m tall (shrub 6 m tall—Gossweiler 9151), d.b.h. up to 30 cm, bole up to 14 m high, secondary branches forming a broad round crown; bark finely fissured. Twigs brown, eventually gray to brown, smooth, spreading-pubescent, the hairs 0.2–0.5 mm long, eventually gray to brown, glabrate; nodes occasionally with two axillary branches. Leaf with larger blades 4.1–9.1 cm long, 1.9–2.9 cm wide, chartaceous, concolorous or slightly discolorous, oblong or lanceolate-oblong, sometimes ovate, apex acute to rounded, base rounded, densely short-pubescent on midrib but otherwise glabrate adaxially, uniformly pubescent abaxially; midrib plane adaxially, raised abaxially, secondary veins indistinctly brochidodromous, 7–11 per side, diverging at 45–70° from the midrib, slightly raised on both surfaces, higher-order veins slightly raised to indistinct on both surfaces; petiole 2–3.2 mm long, shallowly canaliculate, pubescent. Inflorescences axillary or from the axils of fallen leaves, 1–3-flowered, pubescent; peduncle 1 per axil, ca. 0.5 mm long; pedicels up to 3 per peduncle, 1.9–3.3 mm long, 0.5-0.8 mm thick; bracts 2, lower attached near pedicel midpoint and upper subtending sepals, caducous or less often persistent, 2.4–3.6 mm long, ovate to broadly ovate, apex obtuse to rounded; buds linear-lanceolate, apex acuminate. Sepals spreading or slightly reflexed at anthesis, 1/10-connate, 1.3–2.2 mm long, 1.9–2.3 mm wide, coriaceous, broadly ovate to semicircular, apex obtuse to acute, pubescent abaxially. Petals yellowish to olive in vivo, outer petals more or less erect at anthesis, 8.7–11.8 mm long, 2.4–2.9 mm wide at base, 0.6–1 mm wide at midpoint, fleshy, linear-lanceolate, apex more or less acute, pubescent on both surfaces except for the glabrous adaxial base; inner petals probably spreading at anthesis, 6.4–10.3 mm long, 1.9–2.2 mm wide at base, 0.5–0.8 mm wide at midpoint, fleshy, linear-subulate, apex acute, base with margin differentiated into two circular to oblong glands ca. 0.4 wide, pubescent except for the glabrous concavity adaxially, pubescent abaxially. Stamens 75–80; fertile stamens 0.9–1.0 mm long, oblong, apex of connective ca. 0.2 mm long, shieldlike, overhanging the anther thecae, glabrous, anthers 7–8-locellate, filament 0.2–0.3 mm long; outer staminodes 0.8–1.1 mm long, oblong to clavate, apex obtuse to truncate; inner staminodes 0.5-0.8 mm long, oblong to clavate, apex rounded to truncate; staminal cone 0.9–1.1 mm in diameter, 0.4–0.8 mm high, concealing only the bases of the ovaries, rim laciniate. Carpels 3–5; ovaries 0.8–1 mm long, narrowly oblong, pubescent, stigmas loosely connivent, 1.9–2.2 mm long, linear, glabrous except for an apical tuft of hairs. Torus flat, 1.0–1.3 mm in diameter. Fruit of up to 4 sparsely pubescent monocarps borne on a pedicel 5–7.3 mm long, 2.4–3.4 mm thick, sparsely pubescent; torus 4.5–5.7 mm in diameter, 2.5–3.7 mm high, depressed-globose. Monocarps with a green, sometimes red-tinged, exterior in vivo, endocarp color unknown, 2.8–3.9 cm long, 1–1.3 cm wide, 0.9–1.1 cm thick, oblong to clavate, irregularly torulose, apex irregularly obtuse to truncate, base contracted into a stipe 5–9 mm long, 2.3–3.6 mm thick, obliquely wrinkled, verrucose; pericarp 0.6–1.6 mm thick. Seeds up to 6 per monocarp, in a single row, oblique to long axis, 8.5–9.5 mm long, 5.0–6.5 mm wide, 3.7–4.5 mm thick, ellipsoid to flattened-ellipsoid, elliptic to wedge-shaped in cross-section, truncate at micropylar end, rounded at chalazal end, reddish brown to brown, smooth, dull or slightly shiny, raphe/antiraphe not evident, micropylar scar 1.8–2.0 mm long, 1.7–2.1 mm wide, obovate, elliptic, or circular; sarcotesta orange to red-orange in vivo; aril absent.

Phenology

Specimens with flowers have been collected from April to June, and with fruits from May, August to October, and December.

Distribution

(Fig. 24). Occurs near the mouth of the Congo River in Angola, the Republic of the Congo, and the Democratic Republic of Congo in forest bordering savanna and other xerophytic forest types at low elevations.

Local name

Lucangua (Toussaint 373, 2451).

Additional specimens examined

REPUBLIC OF THE CONGO. Région de Pointe-Noire, Pointe-Indienne, 1 Jun 1966 (fl), Sita 1232 (P). DEMOCRATIC REPUBLIC OF THE CONGO. Kongo Central: Luki, 18 Oct 1948 (fr), Donis 2065 (K, P); Prov. Léopoldville, Territ. Boma, Luki, Mar 1959 (buds), Mahieu 290 (K); Mayumbe, Luki, 2 Dec 1946 (fr), Toussaint 2068 (K, MO, P, PRE); Luki, 3 Apr 1947 (fl), Toussaint 2241 (K, MO, P); Luki, vallée de la Mikindu, 4 Sep 1947 (fr), Toussaint 2451 (BR, K, MO, P); Prov. Leopoldville, Territ. Boma, Station a la Mbola, border of savanna and dry forest, 30 Aug 1957 (fr), Wagemans 1696 (K). ANGOLA. Sumba, Peco, 1 May 1923 (fl), Gossweiler 8741 (BM—2 sheets, K, US), Sumba, Peco, May 1926 (fl, fr), Gossweiler 9151 (BM, MO, US).

A poorly known species similar to Xylopia gilbertii, X. toussaintii differs most notably in its longer flowers with proportionately narrower petals. Xylopia toussaintii occurs in an area of strongly seasonal rainfall and corresponding semi-evergreen vegetation (Couralet 2010). We calculated an EOO of 6,766 km2 and an AOO of 16 km2 for Xylopia toussaintii.

Xylopia wilwerthii De Wildeman & T. Durand, Ann. Mus. Congo, Sér. 2, Bot. 1(1): 5. 1899.

Fig. 31

Xylopia wilwerthii var. cuneata De Wildeman in De Wildeman & T. Durand, Bull. Soc. Roy. Bot. Belg. 40(2): 63. 1901. Type. DEMOCRATIC REPUBLIC OF THE CONGO [“Congo Belge”]. Kinshasa Province, Kimuenza, May 1901, J. Gillet s. n. (holotype: BR!; isotype: BR! [0000008825476]).

Type

DEMOCRATIC REPUBLIC OF THE CONGO [“Congo Belge”]. Mongala Province, Rég. III, Upoto, 1896, Capt. Wilwerth s. n. (holotype: BR!, isotype: BM! [000511002]).

Description

Tree up to 15 m tall, d.b.h. up to 10 cm, slender with a short-branched crown. Twigs brown, eventually brownish gray to gray, fine-pubescent, the hairs 0.1–0.2 mm long, soon glabrate; nodes occasionally with two axillary branches. Leaf with larger blades 5.1–8.9 cm long, 1.5–2.8 cm wide, chartaceous, concolorous, elliptic to elliptic-oblong, apex acuminate to caudate, the acumen 5.5–16 mm long and rounded at the tip, base cuneate and somewhat decurrent on petiole; glabrous adaxially, sparsely pubescent to glabrate, occasionally with longer seta-like hairs along midrib abaxially; midrib plane or impressed adaxially, raised abaxially, secondary veins indistinctly brochidodromous and more or less parallel, 15–22 per side, diverging at 60–80° from the midrib, these and higher-order veins slightly raised or indistinct on both surfaces; petiole 1.5–3.5 mm long, shallowly canaliculate, sparsely pubescent to glabrate. Inflorescences axillary, 1-flowered, sparsely pubescent; pedicel not pedunculate, 8.5–21.5 mm long, 0.8–1.0 mm thick, articulated at midpoint, sometimes slightly thickened just proximal to lower bract; bracts 2, the upper attached just a few mm proximal to the sepals, the lower just distal to the pedicel midpoint, more or less persistent, 0.8–1.8 (-2.6) mm long, ovate to semicircular, apex rounded or emarginate, ciliate on margins; buds linear-lanceolate, apex obtuse, slightly falciform. Sepals slightly spreading at anthesis, 1/2–2/3-connate, 2.1–3 mm long, 2.8–3.1 mm wide, coriaceous, broadly ovate, apex acute to mucronate, sparsely pubescent. Petals white, cream-colored, or yellow in vivo; outer petals spreading at anthesis, 19–31 mm long, 3.0–3.5 mm wide at base, 1.9–3.0 mm wide at midpoint, chartaceous, ligulate, apex obtuse, densely puberulent adaxially, sparsely pubescent except for glabrous patch at base abaxially; inner petals probably spreading at anthesis, 14.1–24.0 mm long, 2.0–3.1 mm wide at base, 1.4–1.6 mm wide at midpoint, chartaceous, linear, apex acute, base with undifferentiated margin, puberulent on both surfaces except for the glabrous base. Stamens 100–120; fertile stamens 1.1–1.5 mm long, narrowly oblong, apex of connective 0.1–0.3 mm long, shieldlike, overhanging the anther thecae, finely papillate, anthers 12–13-locellate, filament ca. 0.2 mm long; outer staminodes 1.1–1.6 mm long, oblong, apex obtuse, truncate, or emarginate; inner staminodes 1.0–1.1 mm long, oblong to quadrate, apex truncate; staminal cone 2–2.1 mm in diameter, 0.6–0.9 mm high, partially to completely concealing the ovaries, rim laciniate. Carpels 6–13; ovaries 0.8–0.9 mm long, oblong, pubescent, stigmas connivent, 2.9-3.2 mm long, linear, with a tuft of hairs at the apex. Torus flat, 2.5–3.1 mm in diameter. Fruit of up to 12 glabrate monocarps borne on a pedicel 7.5–23.5 mm long, 2–3 mm thick, glabrate; torus 4.5–7 mm in diameter, 3–5 mm high, irregularly depressed-globose. Monocarps with a green exterior and scarlet endocarp in vivo, 1.7–4.0 cm long, 0.7–1.2 cm wide, 0.5–1.0 cm thick, asymmetrically oblong or ellipsoid, distinctly torulose, apex rounded or with a broad curved beak 1.4–3 mm long, base tapering gradually into a stipe 3–7 mm long, 2.4–4 mm thick, obliquely or longitudinally wrinkled; pericarp 0.4–0.6 mm thick. Seeds up to 6 per monocarp, in a single row, lying parallel or oblique to long axis, 9.6–10.8 mm long, 5.2–7.1 mm wide, 4.9–7.0 mm thick, ellipsoid, elliptic to roughly circular in cross-section, rounded or obliquely truncate at micropylar end, rounded at chalazal end, chestnut brown, smooth, somewhat shining, raphe/antriraphe indistinct, flush with surface of seed, micropylar scar sunken, 1.5–2 mm in diameter, more or less circular; sarcotesta orange in vivo; aril absent.

Figure 31. 

Xylopia wilwerthii A Habit with nearly mature flower bud B Habit, with open flower C Fruit, side view D Seed, view of micropylar end E Seed, side view F Fertile stamen, abaxial view G Staminode, abaxial view H Flower with petals and some stamens removed, side view I Longitudinal section of flower, with petals removed, showing ovaries surrounded by staminal cone J Inner petal, adaxial view K Outer petal, adaxial view. A, C from Carrington 7 (K) B, F–K from Donis 2041 (BR) D, E from Trochain 9603 (P).

Phenology

Specimens with flowers have been collected in March, from May to July, and in September and October, and with fruits from January to March, and in June and October. A ten-year phenology dataset from 1948–1957 from the Luki Reserve in southwestern Democratic Republic of Congo was analyzed by Couralet (2010), who found that X. wilwerthii in the Reserve consistently flowered with the beginning of the rainy season from January to March, with fruit production following shortly thereafter and seed dispersal extending into the dry season from June to September.

Distribution

(Fig. 32). Occurs in and near the lower Congo River drainage in the southern Republic of the Congo, western Democratic Republic of Congo, and the Cabinda Province of Angola, where it grows in lowland forest, gallery forest, and forest/savanna edges at elevations of 400–500 m.

Local names

Bengedele (Donis 2041), bengelele (Devred 3083), nginsa (Pauwels 3478).

Figure 32. 

Distribution of Xylopia wilwerthii. Bolder lines represent country borders, fainter lines lakes and major rivers.

Additional specimens examined

REPUBLIC OF THE CONGO. Foulakari [see below], 21 Sep 1964 (fl), Bouquet 497 (P); région ouest de Brazzaville, chutes de la Fulakari [04°34'58"S, 14°58'27"E], 11 Jun 1960 (fl), Descoings 5852 (P); bord au Congo – Brazzaville, May 1950 (fl), Koechlin 1112 (P); près de Boko (M. Congo), 8 Jan 1956 (fr), Trochain 9603 [6451?] (P). DEMOCRATIC REPUBLIC OF THE CONGO. Kinshasa: Bas-Congo, Kinshasa, Kimuenza, plateau des restents, Luvanium [4.45917°S, 15.288889°E], 28 Mar 1966 (fl, fr), Breyne 96 (MO); Lovanium, plateau of the residence, 400 m, 31 Jul 1965 (fl, fr), Carrington 7 (K); Univ. Lovanium, Léopoldville camp Livulu, 26 June 1961 (fl), Evrard 6317 (MO); Prov. Leopoldville, Territ. Kasangulu, Keimrwenza-Lobanium, plateau near the guest house, 500 m, 29 Jul 1957 (fl), Robyns 4394 (K).—Kongo Central: Luki, Lukula, Parc forestier de la Nkula, 31 June 1978 (buds), Breyne 3348 (MO); Prov. Leopoldville, Zundu, Mbanza-Ngungu [Territ. Thysville], 14 Mar 1960 (fr), Coupère 1675 (K); I. N. E. A. C. Luki, 3 Feb 1947 (fr), Devred 3083 (BR, P); Kiobo, 22 Sep 1945 (fr), Donis 368 (K); Luki, 11 Oct 1948 (fl), Donis 2041 (BR, K, P); Prov. Léopoldville, Terr. Boma, Luki, parc de la n’Kula, Oct 1948 (fr), Maudoux 72 (K, WAG); Bas-Congo, Luki, INEAC, 1957 (fr), Mahieu 53 (BR); Bas-Congo, Luki, 1959, Mahieu 295 (BR).—Kwango: Terr. Popokabaka, Bombo Makuka, 26 Jun 1959 (st), Pauwels 3478 (BR); Luki, 13 Jan 1947 (fr), Toussaint 2114 (K).—Maï-Ndombe: Taketa, terr. Oshwe, 3°15'S, 19°06'E, 21 Jul 1962 (fl), Jans 1110 (BR). ANGOLA. In dense woods E of residence of Bungo Mungo, Mayumbe, 11 Jan 1916 (fr), Gossweiler 6169 (BM).

The long pedicel of Xylopia wilwerthii is unique among African species and unusual within the genus worldwide. This, along with the glabrous caudate leaves, reliably distinguish the species. An unusual aspect of its floral development is that elongation of the axillary pedicel seems to precede elongation of the terminal shoot from which it arises. The orange sarcotesta of its seeds suggest its placement within the X. odoratissima group, but it is isolated there.

Xylopia wilwerthii var. cuneata was distinguished by the leaves being more narrowly cuneate at the bases than in the type specimen of the nominate variety, but we have now seen specimens where this range of variation in the leaf base is encompassed by a single specimen, and the two specimens do not show any other differences, so we do not distinguish them taxonomically. More perplexing is the variation in size and shape of the monocarps; monocarps with larger numbers of seeds are more slender and torulose than those with only 1–3 seeds, which tend to be wider and less strongly constricted between the seeds.

Xylopia wilwerthii and X. flamignii have similar leaves and overlap in distribution, and are thus likely to be confused, especially in the fruiting condition. Xylopia flamignii differs in having a denser persistent indument of the young twigs, a prominent raised reticulum formed by the higher-order veins on the adaxial leaf surface, a distinctly pubescent lower leaf surface, leaves with 13–17 secondary veins per side, up to 22 monocarps per fruit, and seeds only 7–7.6 mm long. Xylopia flamignii is also a larger tree, of up to 30 m in height, reaching canopy or subcanopy level. In contrast, X. wilwerthii is an understory tree with finely pubescent and soon glabrate twigs, indistinct higher-order veins on the adaxial leaf surface, leaves with 15–22 secondary veins per side, never more than 12 monocarps per fruit, and seeds 9.6–10.8 mm long.

Couralet (2010) reported X. wilwerthii, along with Aidia ochroleuca and Corynanthe paniculata, to be a dominant understory species in the Luki Reserve forests, which were characterized as tropical semi-evergreen forest with Prioria balsamifera and Terminalia superba as important canopy species. Forest of Marquesia acuminata was mentioned as the habitat at another site. We calculated a relatively large EOO for X. wilwerthii of 179,602 km2, coupled with an AOO of only 52 km2. The size of the EOO is largely due to the great distance of the type locality, Upoto in the Democratic Republic of the Congo, from the remainder of localities where the plant has been collected.

Xylopia acutiflora group

Plants of this group vary in habit from shrubs to canopy-sized trees or rarely lianas. The leaves of several species, for example X. cupularis, X. hypolampra, and X. villosa, have a fine shiny appressed indument abaxially, a character not seen elsewhere among African species. The inflorescences may consist of a single flower, as in X. acutiflora, or, in the case of X. paniculata, up to 32 flowers, and pedunculate inflorescences are common. Monocarps of many species have a thick woody or leathery pericarp and seeds lying in two rows and oriented more or less perpendicular to the long axis of the monocarp. The sarcotesta of most species in this group is pale green, gray, or blue; X. phloiodora has an orange sarcotesta, and sarcotesta color is unknown for X. acutiflora, X. calva, X. dinklagei, X. elliotii, and X. talbotii. Four species within the X. acutiflora group were included in the molecular phylogenetic analysis of the genus by Stull et al. (2017), and all fell within a strongly supported clade along with several Madagascar species. In Africa this species group has a Guineo-Congolian distribution, reaching its eastern limits in South Sudan, western Tanzania, and central Angola.

Three subgroups within the X. acutiflora group are worth noting, all represented in the Stull et al. (2017) molecular study. The first subgroup comprises X. acutiflora, X. dinklagei, X. mildbraedii, X. monticola, X. piratae, X. talbotii, X. thomsonii, and X. unguiculata, most of them segregates of the former X. acutiflora s. l., These are shrubs, sometimes lianescent, or small trees with single-flowered inflorescences borne on short bract-covered pedicels. A second subgroup includes the common and widespread West and Central African riparian species X. longipetala, formerly known as X. parviflora, and X. katangensis. The third subgroup comprises species with large woody monocarps that often split into three segments upon dehiscence: X. hypolampra, X. letestui, X. paniculata, X. phloiodora, X. tanganyikensis, X. villosa, and probably X. calva. Species with a smaller fruit, which may be associated with this final subgroup, include X. cupularis, X. elliotii, and X. pynaertii.

Xylopia acutiflora (Dunal) A. Richard, Hist. phys. Cuba, Pl. vasc. 1: 55. 1841 [“1845”].

Fig. 33E–G

Unona acutiflora Dunal, Monogr. Anonac. 98, 116, t. 22. Aug–Nov 1817.

Coelocline acutiflora (Dunal) A. de Candolle, Mém. Soc. Phys. Genève 5: 208–209. 1832.

Xylopicrum acutiflorum (Dunal) Kuntze, Revis. gen. pl. 1: 8. 1891. Type. SIERRA LEONE [“Hab. in Americâ meridionali”]. Without definite locality, H. Smeathman s. n. (holotype: G-DC! [00201442]; isotypes: BM! [000510953, 000510954, 000511060, right-hand side of sheet], FI [004821]).

Unona oxypetala Candolle ex Dunal, Monogr. Anonac., Aug–Nov 1817.

Coelocline ? oxypetala (Candolle ex Dunal) A. de Candolle, Mém. Soc. Phys. Genève 5: 209. 1832.

Xylopia oxypetala (Candolle ex Dunal) Engler & Diels, Monogr. afrik. Pflanzen-Fam. 6: 63. 1901. Type. SIERRA LEONE. Without definite locality, A. Afzelius s. n. (lectotype: B! [100249555], as to the material with flowers; isotypes: BM! [000511060, left-hand side of sheet], FI! [005602]).

Description

Tree up to 15 m tall, d.b.h. up to 15 cm; bark smooth, pale brown to gray-brown. Twigs brown, pubescent, with erect hairs 0.7–1.5 mm long mixed with shorter (0.2–0.3 mm) hairs, eventually light gray to gray-brown, glabrate; nodes occasionally with two axillary branches. Leaf with larger blades 5.3–11.7 cm long, 2.3–4.3 cm wide, chartaceous, concolorous to slightly discolorous, elliptic to elliptic-lanceolate, apex acute to acuminate, the acumen (2.5–) 5–11 mm long, base cuneate to broadly cuneate, sparsely pubescent on the midrib but otherwise glabrous adaxially, sparsely appressed-pubescent with longer hairs on the midrib and margin to glabrate abaxially; midrib plane to slightly impressed adaxially, raised abaxially, secondary veins weakly brochidodromous, 9–14 per side, diverging at 60–70° from the midrib, these and higher order veins slightly raised adaxially, raised and forming a reticulum abaxially; petiole 3.2–5 mm long, canaliculate, pubescent to glabrate. Inflorescences axillary, 1-flowered, pubescent; pedicels 3.0–5.5 mm long, 1.2–1.5 mm thick; bracts imbricate on proximal half of pedicel, 3–6, persistent, 1.6–2.6 mm long, obovate, ovate, or orbicular, apex rounded and sometimes apiculate; buds linear-lanceolate, slightly falciform, apex acute to obtuse. Sepals slightly spreading to spreading at anthesis, 1/5–1/4-connate, 2.2–3.7 mm long, ca. 3 mm wide, coriaceous to fleshy, ovate to triangular, apex acute to occasionally acuminate, sericeous abaxially. Petals white to pale yellow, with a patch of red at the base in vivo; outer petals erect to somewhat spreading at anthesis, 19.6–37 mm long, (2.3–) 3.0–3.3 mm wide at base, 1.6–2.0 mm wide at midpoint, coriaceous, linear, apex obtuse, longitudinally ridged abaxially, puberulent but becoming glabrous in the basal third adaxially, sericeous abaxially; inner petals somewhat spreading at anthesis, 16–33 mm long, 2.4–3.2 mm wide at base, 1–1.2 mm wide at midpoint, coriaceous, linear, apex acute, base with undifferentiated margin, longitudinally ridged on both surfaces, pubescent on both surfaces except for the glabrous base. Stamens numerous; fertile stamens 1.4–1.6 mm long, narrowly oblong to clavate, apex of connective red in vivo, 0.2–0.3 mm long, shieldlike, glabrous, anthers 9–12-locellate, filament 0.4–0.5 mm long; outer staminodes 1.5–1.6 mm long, clavate to narrowly oblong, apex rounded to truncate; inner staminodes 0.9–1.1 mm long, rectangular, apex truncate; staminal cone 1.8–2.2 mm in diameter, 1.0–1.6 mm high, concealing lower half of the ovaries, rim laciniate. Carpels 7–13; ovaries ca. 1.2 mm long, oblong, densely pubescent, stigmas connivent, 2.7–3.0 mm long, filiform, glabrous except for an apical tuft of hairs. Torus concave beneath ovaries but otherwise flat, 1.8–2.5 mm in diameter. Fruit of up to 10 glabrate monocarps borne on a pedicel 5–9 mm long, 2.3–5.6 mm thick, sparsely pubescent to glabrate, often with short dead branch attached and bracts and sepals persistent; torus 5.9–11.5 mm in diameter, 4.2–7.5 mm high, depressed-globose, sunken where monocarps attached. Monocarps with a green, sometimes reddish-tinged, exterior and a scarlet endocarp in vivo, 2.5–5.1 cm long, 1.1–1.5 cm wide, 1.2–1.3 cm thick, oblong, sometimes weakly torulose, apex obtuse or with an oblique truncate beak 1.5–2 mm long, base contracted into a stipe 3–7 mm long, 2.9–4.5 mm thick, longitudinally ridged or wrinkled, verrucose; pericarp 0.7–1.2 mm thick. Seeds up to 20 per monocarp, in two rows, lying perpendicular to long axis, 11–12 mm long, 6.5–7.9 mm wide, 5.8–5.9 mm thick, ovoid to ellipsoid, wedge-shaped in cross-section, truncate at micropylar end, rounded at chalazal end, brown, smooth, dull, raphe/antiraphe not evident, micropylar scar ca. 3.5 mm long, ca. 1.5 mm wide, oblong-ovate; sarcotesta color unknown in vivo, forming a waxy crust on dried seeds; aril absent.

Figure 33. 

Xylopia unguiculata, X. acutiflora, and X. piratae. A–D, L–O X. unguiculata A Monocarp, lateral view B Seed C Leaves D Flower, lateral view L, M Staminodes, abaxial view N Stamen, abaxial view O Carpel, lateral view with ovary wall cut away to show arrangement of ovules E–G X. acutiflora E Monocarp, lateral view, attached to pedicel F Leaves G Flower, lateral view H–K X. piratae H Flower bud, lateral view I Leaves J Flower, lateral view K Fruit. A–B from Le Testu 1179 (BM) C–D from Reitsma & Reitsma 1923 (NY) E–G from Beentje 879 (WAG) H–J from de Koning 4999 (WAG) K from de Wilde 356 (P) L–O from McPherson 16960A (MO).

Phenology

Specimens with flowers have been collected from February to June and in September, and with fruits in February and from August to October.

Distribution

(Fig. 34). Occurs in Sierra Leone, Guinea, Liberia, and Ivory Coast, in both primary and secondary forests at low to middle elevations.

Local names

Elo blanc (Aubréville 90), gbaa (Yallah 51).

Figure 34. 

Distributions of Xylopia acutiflora, X. dinklagei, X. monticola, X. piratae, X. thomsonii, and X. unguiculata. Bolder lines represent country borders, fainter lines lakes and major rivers.

Additional specimens examined

GUINEA. Environs de Forécariah, bosquet de Kankan nara, Jun 1937 (fl), Jacques-Félix 1715 (P). SIERRA LEONE. Kabala, Mt. Loma, Seisikoro, 6 Dec 1965 (st), Adam 22396 (MO); Falaba, 2 Apr 1914 (fl), Aylmer 29 (MO); Gola Forest, 25 Apr 1952 (buds), Small 639 (B, MO); Gola Forest, 14 May 1952 (fl), Small 664 (MO). LIBERIA. Yekepa, Mt. Nimba, 13 Oct 1969 (st), Adam 24221 (MO); Yèkèpa, Yekepa, Mt. Nimba (Mt. Yuelliton), 25 May 1970 (fl), Adam 25678 (K, MO); Yekepa, Mt. Nimba (Mt. Gangra), 21 Oct 1971 (fr), Adam 26395 (MO, P); Yekepa, Nimba, New Camp Grassfield, 14 May 1973 (fl), Adam 27551 (MO, P, PRE, WAG); Eastern Province, Tchien District, Ziah Town [“Zeahtown”], 1 Aug 1947 (fr), Baldwin 6970 (K, MO); Monserrado Co., Bomi Hills, 3 Feb 1950 (fl), Baldwin 14086 (K, MO, NY, US); Gola-Yoma National Forest, Bomi Hills, 6 Feb 1966 (fl), van Meer 390 (MO, WAG); Nimba area, 10 Apr 1962 (fl), Voorhoeve 1089 (B, M, MO, WAG—2 sheets); Gola National Forest, ca. 15 km NE of Bomi Hills, 17 Apr 1962 (fl), de Wilde & Voorhoeve 3833 (A, B, BR, K, P, WAG—3 sheets); Mt. Bele, 16 Apr 1965 (fl), Yallah 51 (K, P). IVORY COAST. Taï (Aubréville 1959), without definite locality, 9 Feb 1957 (fr), Aubréville 90 (P—3 sheets); 10 km ESE of Taï, 05°50'N, 07°22'W, 6 Sep 1975 (fl, fr), Beentje 879 (WAG—2 sheets); vicinibus oppidi Tienkulà, ad occidentem reipublicae, 1 Mar 1962 (fl), Bernardi 8315 (A, G—2 sheets, K, M, MO, US—2 sheets); 80 km S of Soubré, 3 Apr 1968 (fl), Geerling & Bokdam 2478 (K, MO, WAG—2 sheets); Taï, 11 Sep 1975 (fl, fr), de Koning 5996 (MO, WAG—2 sheets); Guiglo, Taï, 05°52'N, 7°27'W, 1 Mar 1982 (fl), Stäuble NS 0460 (MO).

Xylopia acutiflora is one of six species belonging to a geographically widespread complex of species that vary in habit, indument, and flower and fruit morphology, but all formerly considered as representing a single species. Xylopia acutiflora s. s. is a small tree, with a mix of short and long hairs on the twigs, petals reaching 37 mm in length, and short broad monocarps with two rows of seeds. It is restricted to a relatively small area of West Africa in lowland and lower montane forests. It overlaps in Liberia with X. dinklagei, but that species is a shrub or liana with uniform short hairs on the twigs, petals reaching only 13 mm in length, and longer and narrower monocarps with a single row of seeds. Xylopia piratae from the Ivory Coast and Ghana likewise differs in being a liana with narrow monocarps, but has variable twig indument like X. acutiflora and much longer petals, reaching 73 mm in length.

Information about Xylopia acutiflora pertaining to plants from areas east of Ivory Coast probably applies to other species. In most cases, these refer to segregate species of the larger X. acutiflora complex, but the report of X. acutiflora for the Flora Zambesiaca area (Robson 1960) is based on the specimen Holmes H.1273 (K), which is not a member of this group at all. It is most similar to X. elliotii and is discussed under that species.

The ecology of X. acutiflora is largely unknown. In Taï National Park in western Ivory Coast, the seeds of Xylopia acutiflora were eaten and spat out by the monkey, Colobus polykomo, which fed on the seeds of other Xylopia species as well (Koné et al. 2008). A new rust species, Sphaerophragmium xylopiae Beenken & R. Berndt, was recently described from teliospores found attached to the specimen Bernardi 8315 (Beenken and Berndt 2010). This rust genus seems to be confined to Fabaceae and Annonaceae.

Historically, there has been confusion over the application of the name Xylopia acutiflora. Bentham (1862) accepted three African species of Xylopia, X. aethiopica, X. acutiflora, and X. parviflora, the latter being a new combination based on the Uvaria parviflora Rich. Bentham expressed doubt, however, about the distinctness of the latter two species, and even whether the plant described as Unona oxypetala Dun. was distinct from them. The specimens cited by Bentham under both X. acutiflora (Barter from the confluence of the Quorra and Chadda Rivers, Chr. Smith from the Congo) and X. parviflora (Vogel and Barter from the Niger, G. Mann from the Bagroo River) are all Xylopia longipetala. Oliver (1868) maintained Bentham’s concept, and it is not surprising that Vallot (1882) found it necessary to argue that there were two distinct species, and that Bentham had confused them. Vallot proposed Xylopia dunaliana Vallot as a replacement name for X. acutiflora (under which he placed Unona oxypetala in synonymy), and he retained the name X. parviflora for the second species, but X. dunaliana Vallot is a superfluous name and illegitimate.

The type material of Unona acutiflora in G-DC comprises 4 sheets of a collection made by Smeathman, each sheet with slightly different labeling but all seeming to contribute to the description and illustration in Dunal (1817) and so here regarded as the holotype. There are three sheets of a Smeathman collection at BM that are considered to be isotypes. As with the combination Xylopia aethiopica made by Richard, we follow the conclusion of Brizicky (1962) in accepting the year of publication of the combination Xylopia acutiflora as 1841, rather than the printed date of 1845. Dunal published Candolle’s manuscript name Unona oxypetala in the same publication as Unona acutiflora (Dunal 1817), which was based on a specimen collected by Afzelius and seen by Candolle in the Lambert Herbarium. The two names therefore have equal priority, but the name X. acutiflora has historically been used for the species. According to Miller (1970), the specimens of Afzelius in the Lambert Herbarium were purchased by William Pamplin, working on commission for Wilhelm Friedrich Klotzsch, who acquired the specimens for the Berlin herbarium. An Afzelius specimen, identifiable as this species, survives at B, but the specimen has both flowers and fruits, and only flowers are mentioned in the protologue. The fruits and seeds are not attached to the twigs, and it is possible that they became associated with the specimen later. We initially labeled the B sheet as an isotype, pending a better understanding of the distribution of the Lambert Herbarium collections, but it is now clear that this specimen, and specifically the branches with flowers attached, is more appropriately designated as a lectotype.

Xylopia calva D. M. Johnson & N. A. Murray, sp. nov.

Fig. 35Q–T

Diagnosis

Species resembling Xylopia phloiodora in the short branched inflorescences and large ellipsoid fruits, but differing in the much broader oblong-lanceolate petals that are glabrous adaxially except for a fringe of hairs on the apices, the leaves sometimes glaucous abaxially, the staminal cone smaller and the rim laciniate, the anthers only 10–13-locellate, and the lack of pronounced reticulum on the adaxial surface of the leaf.

Type

CAMEROON. South Region, Bipinde, 1903 (fl), G. A. Zenker 4747 (holotype: BM [000511011]; isotypes: G! K! L! [0191105], M! MO! [751089]).

Description

Tree of unknown height, d.b.h. 30 cm, bole straight, cylindrical, slender, with buttresses reaching a height of 1 m from the base; bark pinkish gray with white flecks, smooth. Twigs dark brown to gray, pubescent, the hairs 0.3–0.4 mm long, soon glabrate; nodes occasionally with two axillary branches. Leaf with larger blades 10–17.2 cm long, 3.6–6.5 cm wide, chartaceous to subcoriaceous, concolorous but sometimes slightly glaucous abaxially, elliptic to elliptic-oblong, apex acuminate, the acumen (3–) 9–21 mm long, base broadly cuneate to rounded and short-decurrent on the petiole, with a few hairs along the midrib adaxially, sparsely appressed-pubescent abaxially; midrib plane to slightly impressed adaxially, raised abaxially, secondary veins irregularly brochidodromous, 8–15 per side, diverging at 50–65° from the midrib, these and higher-order veins slightly raised on both surfaces; petiole 3–10 mm long, shallowly canaliculate, sparsely pubescent. Inflorescences axillary, 1–10-flowered, rusty-pubescent; peduncle 1 per axil, 1–3 mm long; pedicels 1–10 per peduncle, 5–8 mm long, 1.3–1.5 mm thick; bracts 1–2, evenly spaced on pedicel, the lower caducous and the upper persistent, 2–3 mm long, broadly ovate to semicircular, apex obtuse to acute; buds lanceolate, apex obtuse. Sepals slightly spreading at anthesis, 1/4–1/3 connate, 3.8–4.5 mm long, 4.4–5.1 mm wide, coriaceous, broadly ovate, apex acute to obtuse, densely rusty-pubescent abaxially. Petals pale yellow, inner petals reddish at the base adaxially in vivo; outer petals probably slightly spreading at anthesis, 13–23 mm long, 3.8–6 mm wide at base, 2.8–5.5 mm wide at midpoint, fleshy, oblong-lanceolate, apex obtuse, densely puberulent only on trigonous apex adaxially, appressed-pubescent except for a glabrous patch at the base abaxially; inner petals probably slightly spreading at anthesis, 10–17.5 mm long, 2.5–4 mm wide, 2.2–3.0 mm wide at midpoint, fleshy, oblong-lanceolate, apex acute, base with undifferentiated margin, puberulent at apex but otherwise glabrous adaxially and uniformly puberulent except for the glabrous base abaxially. Stamens ca. 200; fertile stamens 1.4–2.2 mm long, narrowly oblong, apex of connective red in vivo, 0.1–0.3 mm long, dome-shaped to shieldlike, overhanging the anther thecae, papillate, anthers 10–13-locellate, filament 0.7–0.8 mm long; outer staminodes 2.1–2.8 mm long, clavate to oblong, apex obtuse, rounded, or truncate; inner staminodes 1.1–1.2 mm long, oblong, apex truncate; staminal cone 1.6-2.5 mm in diameter, 0.9–1 mm high, partially concealing the ovaries, rim laciniate. Carpels ca. 9; ovaries ca. 1.8 mm long, narrowly oblong, pubescent, stigmas connivent at the base, ca. 2.2 mm long, linear but thickened in the middle, with a tuft of hairs at the apex. Torus flat, 2.5–3.5 mm in diameter. Fruit of up to 8 pubescent monocarps borne on a pedicel 6–6.8 mm long, 2.4–2.5 mm thick, rusty-pubescent; torus 5.8–6 mm in diameter, 3–4.5 mm high, depressed-globose. Monocarps ca. 3.2 cm long, ca. 1.7 cm wide and thick, ellipsoid, not torulose, apex obtuse, base narrowed, contracted into a stipe ca. 3 mm long, ca. 7 mm thick, longitudinally wrinkled, with strips of rusty pubescence; pericarp ca. 2.5 mm thick. Seeds 7–8 per monocarp, in two rows, lying perpendicular to long axis, ca. 9.3 mm long, 6.5–6.8 mm wide, 4.5–6.1 mm thick, oblong, elliptic in cross-section, truncate at micropylar end, rounded at chalazal end, brown, smooth or slightly wrinkled, dull, raphe/antiraphe faintly evident, micropylar scar not observed; sarcotesta in vivo unknown; aril absent.

Figure 35. 

Xylopia phloiodora, X. paniculata, and X. calva. A–L X. phloiodora A Opening flower, lateral view B Old floral receptacle, showing staminal cone C Leaf, narrow extreme D Habit E Expanding vegetative shoot F, G Stamens, abaxial view to show size variation H Outer petal, adaxial view I Inner petal, adaxial view J Fruit K Seed, view from micropylar end L Seed, lateral view M–P X. paniculata M Inflorescence N Flower with petals and stamens removed, to show staminal cone O Inner petal, adaxial view P Outer petal, adaxial view Q–T X. calva Q Inflorescence R Flower with stamens and petals removed, to show staminal cone S Inner petal, adaxial view T Outer petal, adaxial view. A, B, D, F–I from Louis 13430 (US) C from Louis 7220 (WAG) E from Tisserant 1113 (BM) J from Tisserant 1138 (P) K, L from Fay and Harris 1138 (MO) M–P from Reitsma & Reitsma 1163 (NY) Q–T from Letouzey 10306 (P).

Phenology

Specimens with flowers were collected in April, and with young fruits in May.

Distribution

(Fig. 36). Known from three localities, two of them in southwestern Cameroon and the other in south-central Nigeria, from low elevation forest.

Local name

Ohun (Ross R.202).

Figure 36. 

Distributions of Xylopia phloiodora, X. paniculata, and X. calva. Bolder lines represent country borders, fainter lines lakes and major rivers.

Additional specimens examined

NIGERIA. Edo State, Okomu Reserve, near U. A. C. timber camp, Onikaroga, 12 May 1934 (yg fr), Ross R.202 (K). CAMEROON. Près des chutes du Ntem ou de Menve’ele près Nyabessan (60 km E de Campo), 8 Apr 1970 (fl), Letouzey 10306 (P).

Xylopia calva is distinguished by its long broad petals that are glabrous adaxially (L. calva, “bald”) except at the apices. It is most similar to X. phloiodora, having the same pedunculate and branched inflorescence found in that species, but may be distinguished by the glaucous tinge to the abaxial surface of the leaves, straight rather than arcuate secondary veins, indistinct higher-order venation, outer petals 2.8–5.5 mm wide at the midpoint, anthers only 10–13-locellate, and laciniate rim of the staminal cone. The only fruit seen was not fully mature.

The type specimen was initially identified as Xylopia aethiopica and filed in herbaria under that name. The other two specimens were only identified as “Xylopia sp.” The specimen Ross R.202 is labeled as having been seen for the second edition of Flora of West Tropical Africa (Keay 1954–1958), but there is no mention of this specimen in the Xylopia treatment of that work. We calculated an EOO of 22,406 km2 and an AOO of 12 km2 for this species; the fact that there are only three collections, the most recent one from 1970, suggests that the species should be of conservation concern.

Xylopia cupularis Mildbraed, Notizbl. Bot. Gart. Berlin-Dahlem 8: 56–57. 1921.

Fig. 37

Xylopia gilviflora Exell, J. Bot. 73: Suppl. 4. 1935. Type. ANGOLA [“Portuguese Congo”]. Cabinda Province, in the forests at Buco Zau, Mayumbe, 15 Jan 1917, J. Gossweiler 6933 (holotype: BM!, photos at GH! MO! NY!; isotypes: B! [100153140], COI! [00004882], LISC! [000308, 000309, 000310, 000311, 000312, 000313, 000314, 000315, 000316]).

Xylopia chrysophylla J. Louis ex Boutique, Bull. Jard. Bot. État 21: 108–109. 1951. Type. DEMOCRATIC REPUBLIC OF THE CONGO [“Belgian Congo”]. Tshopo Province, District Forestier Central, Yangambi, à 7 Km à l’Est du poste, alt ± 470 m, June 1937, J. Louis 4309 (holotype: BR!; isotypes: AAU! BR! [0000008824752], L! MO! [1639095, 3007016], NY! [00066781], US! [2091336]).

Type

CAMEROON. East Region, weit nach Norden vorgeschobener Ausläufer des äquatorialen Waldgebietes südlich Deng-deng, etwa 250 km nordöstlich Jaunde, Mar 1914, J. Mildbraed 8649 (holotype: B! [100153141]; isotype: BM! [000511053]).

Figure 37. 

Xylopia cupularis. A Bud and partially open flower B Diagrammatic drawing of dehisced monocarp, showing seed arrangement C Fruit D Longitudinal section of flower with petals removed, to show the calyx, stamens attached to staminal cone, and carpels inside the cone E Stamen, abaxial view F Base of inner petal, adaxial view G Leaves H Seed, viewed from micropylar end I Seed, side view J Detail of indument on lower leaf surface. A, D–G from Gerard 5583 (MO) B, C, H–J from Sita 4118 (P).

Description

Tree up to 35 m tall, d.b.h. up to 50 cm; bole cylindrical, with small buttresses at the base; bark light-colored, tinted with pink, gray, brown, or green, smooth. Twigs reddish brown, finely appressed-pubescent, the hairs 0.1–0.3 mm long, eventually gray brown to light gray, glabrate; nodes commonly with 2–3 axillary branches. Leaf with larger blades 4.6–7.8 cm long, 1.3–2.4 cm wide, chartaceous, discolorous, lanceolate to elliptic or elliptic-oblong, apex acuminate (sometimes minutely truncate), the acumen 6–11 mm long, base cuneate to broadly cuneate, often slightly oblique, with a few hairs on the midrib but otherwise glabrous adaxially, sparsely to densely golden-sericeous abaxially, becoming more sparsely so with age; midrib slightly raised adaxially, raised abaxially, secondary veins indistinctly brochidodromous, 10–15 per side, diverging at 45–60° from the midrib, these and higher-order veins slightly raised on both surfaces, less distinct abaxially; petiole 2–5 mm long, flat to shallowly canaliculate, sparsely pubescent. Inflorescences axillary, 1–2 (–3)-flowered, sparsely pubescent; peduncles rarely present, up to 4 mm long; pedicels usually not pedunculate, rarely up to 3 per peduncle, 4.5–12 mm long, 0.7–0.9 mm thick; bracts 2, both attached distal to pedicel midpoint, caducous, 1.5–1.9 mm long, semicircular, apex broadly acute to obtuse; buds linear-lanceolate, apex acute. Sepals erect to slightly spreading at anthesis, 1/2–3/4-connate, 2.1–3.3 mm long, 2.5–3.5 mm wide, coriaceous, broadly ovate, apex broadly acute to obtuse, pubescent abaxially. Petals cream-colored to yellow in vivo; outer petals appear spreading at anthesis, 15.5–36 mm long, 2.2–3.4 mm wide at base, 1.2–2.2 mm wide at midpoint, fleshy, linear-lanceolate, apex acute, densely pubescent adaxially, sericeous abaxially; inner petals appear spreading at anthesis, 13.5–17.7 mm long, 2.4–3.5 mm wide at base, 0.9–1.5 mm wide at midpoint, fleshy, linear, apex acute, base with undifferentiated margin, puberulent on both surfaces except for glabrous base. Stamens 160–200; fertile stamens 1.0–1.6 mm long, narrowly oblong, apex of connective 0.1–0.3 mm long, depressed-globose, overhanging the anther thecae, glabrous, anthers 9–10-locellate, filament 0.2–0.6 mm long; outer staminodes 1.3–1.4 mm long, oblong, apex obtuse to rounded; inner staminodes 0.9–1.0 mm long, oblong, apex truncate; staminal cone 1.7–2.3 mm in diameter, 0.7–1.0 mm high, partially concealing the ovaries, rim laciniate. Carpels 12–20; ovaries ca. 1 mm long, ellipsoid to oblong, densely pubescent, stigmas connivent, 2.5–2.8 mm long, filiform, with a tuft of hairs at the apex. Torus flat, 2.1–2.7 mm in diameter. Fruit of up to 18 glabrate monocarps borne on a pedicel 6–15 mm long, 3–10 mm thick, glabrate; torus 6.6–16 mm in diameter, 5–6.5 mm high, depressed-globose. Monocarps with reddish green exterior and pink to dark red endocarp in vivo, 2.3–5.4 cm long, 1.4–1.9. cm wide, 1.2.–2.0 cm thick, irregularly oblong or obovoid, weakly torulose, apex rounded, base contracted into a stipe (5–) 7–24 mm long, 1.5–5 mm thick, sometimes wrinkled, verrucose; pericarp 0.8–2 mm thick. Seeds 6–8 per monocarp, in two rows, lying oblique to perpendicular to long axis, 9.6–13.4 mm long, 6.1–9.6 mm wide, 5.5–7 mm thick, flattened-ellipsoid to broadly ellipsoid, wedge-shaped in cross-section, truncate at micropylar end, rounded at chalazal end, dark brown, mostly smooth but finely marked with pits and wrinkles, dull, raphe forming a keel, antiraphe partially sunken into a groove but not evident by the micropylar scar, micropylar scar 1.5–2.6 mm long, 0.6–2.3 mm wide, ovoid, oblong, or deltoid; sarcotesta glaucous blue or gray in vivo; aril absent.

Phenology

Specimens with flowers have been collected in all months of the year, and with fruits in all months except February, March, and December.

Distribution

(Fig. 38). Distributed from southeastern Nigeria east to the southern Central African Republic and south to Cuanza Sul Province of Angola and the northeastern Democratic Republic of the Congo, occurring in rainforest, semi-deciduous forest, forest-savanna edges, and secondary forest at elevations of 50–800 m.

Local names

Aganda (Basoko, Louis 4309), bompaie bo fufow bo lowe (Turumbu, Louis 4309), inaolo a bompaie bo fufow (Turumbu, Louis 16550), lucangua (Matton 11), molo-nyama (Lissongo, Tisserant 2295), molo-nzange (Lissongo, Tisserant 1768), odjobi (Yaoundé, Mbarga 1940 SRFK), sange (Ekuba 1615, Hart 572), sange-petite (Kibila, Marabo 1546).

Figure 38. 

Distributions of Xylopia cupularis and X. tanganyikensis. Bolder lines represent country borders, fainter lines lakes and major rivers.

Representative specimens

NIGERIA. Benin Province, Iyekuselu District, in field 8 at W. A. I. F. O. R., 8 Dec 1961 (fl), Daramola FHI 45672 (K). CAMEROON. Subdivision Eseka près de Badjob, 17 Jun 1955 (fl), Mbarga 58 [SRFK 1940] (P); Likomba-Pflanzung, 15–35 km NE von Victoria, 50–100 m, Nov 1928 (st), Mildbraed 10629 (A, K); PK 30 route Mintom I (70 km E de Djoum)-Alati (100 km SE de Djoum), 8 Jan 1973 (fl), Letouzey 11801 (BR, K, P, WAG); South West Province, Mount Cameroon, Mabeta peninsula, Mabeta, 19 Oct 1997 (st), Tchouto et al. 1756 (MO). CENTRAL AFRICAN REPUBLIC. Ndakan Gorilla Study Area, 02°21'N, 16°10'E, 385 m, 15 Jul 1988 (fr), Fay & Harris 8535 (MO); Sangha-Mbaere, Ndakan Gorilla Study Area, 385 m, 25 Jul 1988 (fr), Fay & Harris 8546 (MO); [Oubangui], Boukoko, 19 Aug 1947 (fl, fr), Tisserant 138 (BM, BR, K, MO, P); 17 Sep 1947 (fl), Tisserant 246 (BM, G, P); [Oubangui], Boukoko, 6 Oct 1947 (fl), Tisserant 315 (BM, K, P); 15 Dec 1948 (fl), Tisserant 1287 (BM, K, P); 7 Jun 1950 (fr), Tisserant 1768 (BM, P); région de Boukoko, 28 Nov 1951 (fr), Tisserant 2295 (BM, BR, P). GABON. Ogooué-Ivindo: Lopé-reserve, 0°30'S, 11°33'E, 28 Nov 1986 (st), Reitsma & Reitsma 2622 (MO, NY, WAG); Reserve de la Lopé, 0°15'S, 11°40'E, 3 Oct 1992 (fr), White 371 (MO); SEGC Lopé Reserve, 0°15'S, 11°40'E, 18 Jun 1991 (fr), White 489 (MO).—Ogooué-Lolo: Bambidie, about 30 km E of Lastoursville, 300 m, ca. 0°44'S, 12°58'E, 13 Nov 1999 (fr), Breteler 15468 (WAG); région de Lastoursville, Lastoursville, 25 Feb 1930 (fl), Le Testu 7937 (BM, NY, P). REPUBLIC OF THE CONGO. Chaillu, ouest-Mossendjo, région de Kouyi, plaine ou steppe de Mussanda sur dalle cuirassée [02°57'S, 12°44'E], 23 Apr 1977 (fr), Sita 4118 (BR, P, WAG). DEMOCRATIC REPUBLIC OF THE CONGO. Bas-Uele: Digba, Prov. Orientale, Terr. Ango, forêt des Akare entre riviére Bili et Asa, 29 Nov 1963 (fl), Gerard 5583 (K, MO, WAG).—Équateur: Yalifake (Région Mondombe, Terr. Ikela) [0°37'S, 22°42'E], 6 May 1959 (fl), Evrard 6266 (BR, K).—Ituri: Zone de Mambasa (Ituri Forest), Lenda, 1°19'N, 28°38'E, 750 m, 2 Jun 1994 (fr), Ekuba 1615 (MO, WAG); Zone de Mambasa (Ituri), Epulu, 1°25'N, 28°35'E, 750 m, forêt mixte à 25 km nord-ouest d’Epulu, 26 Jul 1986 (fl), Hart 572 (BR, MO); Zone de Mambasa (Ituri Forest), Afarama, 1°33'N, 28°32'E, 800 m, 27 Apr 1973 (fl), Marabo 1546 (BR, K, MO).— Kongo Central: Prov. Léopoldville, Mbanza-Ngungu [“Territ. Thysville”], forêt de Kinganga, Oct 1958 (fl, fr), Davio 10 (A, B, BR, P, WAG); Luki, 8 May 1947 (fr), Donis 1441 (P); Route Interieure, Luki, 27 Jul 1957 (fr), Matton 11 (BR); Luki, Toussaint 2187 (K).— Kwilu: Kiyaka-Kwongo, Prov. Kinshasa, Terr. Kikwit, 6 Sep 1955 (fl), Devred 2565 (K, WAG).—Maniema: Kivu Prov., Territ. Kindu, Beondo, 21 Apr 1959 (fr), Bamps 597 (K).—Tshopo: Prov. Orientale, Terr. Tsangi, Yangambi, ca. 470 m, 14 Jan 1952 (fr), Donis 3404 (K, MO); Yangambi, 470 m, 8 Aug 1936 (fl), Louis 2393 (B, BM, K, MO, P, US), 15 Jan 1938 (st), Louis 7522 (NY, PR, RSA), s. d. (fr), Louis 16550 (BR, K). ANGOLA. Cabinda: Pango Manga, 22 Jan 1916 (fl), Gossweiler 6185 (BM).—Cuanza Sul: Amboim, Capir, proximum flumen Carloango-Cuvo, 900 m, Sep 1932 (fr) Gossweiler 9903 (K—2 sheets).

Xylopia cupularis is distinctive among African Xylopia species for its combination of small acuminate leaves with abaxial golden appressed pubescence, relatively long pedicels, sepals connate into a cup-shaped calyx, and the large number (up to 18) of monocarps, which are usually distinctly stipitate, and the circular seeds on which the raphe is distinctly keeled for part of its length. Some specimens of X. phloiodora, e.g. Tisserant 955, can resemble it, but may be distinguished by the strongly reticulate adaxial surface of the leaf, the persistent distal bract on the pedicel, the more rounded staminal cone, the smaller number of carpels, and the stigmas broader, warty, and lacking apical hairs.

While the long stipes on the monocarps are distinctive, there is variability in the character. Collections from the Central African Republic exemplify this. In the collections of Fay and Harris, the stipes are short and wide, i.e. 5 by 5 mm, while those in Tisserant 2295 are long and slender (up to 24 mm long). On the specimen Tisserant 1768, the stipes are 5–8 mm long and 3.5–5 mm thick. In the case of specimens with short stipes on the monocarps, the tendency toward large numbers of monocarps per fruit is helpful in identification.

In many herbaria, collections of this species were filed under the Xylopia chrysophylla, a name based on a specimen from Yangambi in the Democratic Republic of the Congo. We could not distinguish either the type of X. chrysophylla or the type of X. gilviflora from X. cupularis, and follow Paiva (1966) in placing the newer names as taxonomic synonyms of X. cupularis.

In the protologue for Xylopia cupularis, Mildbraed mentions a second specimen, Staudt 525, but points out that the specimen is sterile and that it cannot be identified as this species with certainty. The specimen is therefore not regarded as having any type status with respect to this name.

Xylopia dinklagei Engler & Diels, Notizbl. Königl. Bot. Gart. Berlin 2: 298. 1899.

Fig. 39G–I

Xylopicrum dinklagei (Engler & Diels) Kuntze, Deutsch. Bot. Monatsschr. 21: 173–174. 1903. Type. LIBERIA [“Oberguinea”]. Grand Bassa County, Grand Bassa, 18 Oct 1896, M. Dinklage 1760 (lectotype, here designated: B! [100249554]; isolectotype: A!; possible isolectotypes (see below): B! [100153126, 100153127]).

Description

Shrub or low climber. Twigs brown, pubescent, the hairs 0.1–0.3 mm long, eventually glabrate; ultimate branches often thickened at base. Leaf with larger blades 6–9.9 cm long, 1.8–3.3 cm wide, chartaceous to subcoriaceous, concolorous to slightly discolorous, oblong to elliptic, apex acuminate, the acumen 5–11 mm long, base broadly cuneate to rounded, pubescent on the midrib but otherwise glabrous adaxially, finely appressed-pubescent abaxially; midrib plane to slightly impressed adaxially, raised abaxially, secondary veins weakly brochidodromous, 10–11 per side, diverging at 60–70° from the midrib, plane or slightly raised and indistinct adaxially, slightly raised abaxially, higher-order veins indistinct or slightly raised on both surfaces; petiole 2–4.5 mm long, canaliculate, sparsely pubescent to glabrate. Inflorescences axillary, 1-flowered, pubescent; pedicels 2.3–3.3 mm long, 1.2–1.4 mm thick; bracts 3–4, imbricate, persistent, 1.1–1.8 mm long, broadly ovate to semicircular, apex obtuse to rounded; buds lanceolate, apex acute. Sepals slightly spreading at anthesis, 1/4–1/3-connate, 2.3–2.7 mm long, 2.9–3.3 mm wide, coriaceous, broadly triangular to orbicular, apex acute, sericeous abaxially. Petals pale yellow in vivo; outer petals possibly somewhat spreading at anthesis, 10.5–13 mm long, 2.5–3.4 mm wide at base, 1.6–2.0 mm wide at midpoint, coriaceous, narrowly lanceolate, apex obtuse, pubescent, but becoming glabrous in the center toward the base adaxially, sericeous abaxially; inner petals possibly erect or spreading at anthesis, 8.5–10.7 mm long, 2.4–2.7 mm wide at base, 0.8–1.2 mm wide at midpoint, coriaceous, linear-subulate, apex acute, base with undifferentiated margins, pubescent on both surfaces except for the glabrous base. Stamens ca. 120; fertile stamens 1.3–1.5 mm long, narrowly oblong, apex of connective 0.2–0.3 mm long, shieldlike, overhanging anther thecae, glabrous, anthers 9–10-locellate, filament ca. 0.4 mm long; outer staminodes 1.4–1.5 mm long, clavate, apex obtuse to truncate; inner staminodes 0.8–1.0 mm long, quadrate, apex obtuse to truncate; staminal cone 1.7–2.0 mm in diameter, 0.7–1.1 mm high, concealing the ovaries, rim laciniate. Carpels 12–15; ovaries 1.3–1.4 mm long, narrowly oblong, densely pubescent, stigmas connivent, 2.4–2.8 mm long, filiform, apex acute, with tuft of hairs at apex but otherwise glabrous. Torus flat, ca. 2.1 mm in diameter. Fruit of up to 13 glabrate monocarps borne on a pedicel 4.5–5 mm long, 3.2–5.6 mm thick, sparsely pubescent, sometimes with short dead branch attached and bracts and sepals persistent; torus 8–11 mm in diameter, 5–6.3 mm high, depressed-globose. Monocarps with green exterior in vivo, endocarp color unknown, 3.6–7.7 cm long, 1.2–1.5 cm wide, 0.9–1.1 cm thick, narrowly oblong and slightly falciform, torulose, apex with a curved beak 2–4 mm long or occasionally obtuse, base contracted into a flat stipe 6–8 mm long, 2–3 mm thick, longitudinally ridged or wrinkled, verrucose; pericarp ca. 0.4 mm thick. Seeds up to 10 per monocarp, commonly 5–7, in a single row, lying oblique to long axis, 10.5–11.5 mm long, 6.8–7.6 mm wide, 5–6 mm thick, flattened-ellipsoid, oblong to elliptic in cross-section, truncate at micropylar end, rounded at chalazal end, tan, smooth, faintly shiny, raphe/antiraphe not evident, micropylar scar 4.5–5 mm long, 2.5–3.5 mm wide, elliptic; sarcotesta unknown in vivo; aril absent.

Figure 39. 

Xylopia thomsonii, X. monticola, X. talbotii, and X. dinklagei. A–C X. thomsonii A Fruit B Leaf C Flower D–E X. monticola D Flower E Leaf and fruit F X. talbotii, flower, side view G–I X. dinklagei G Leaf H Flower I Fruit. A from de Wilde & de Wilde-Duyfjes 2703 (K) B, C from Talbot & Talbot 3267 (BM) D from Chapman 3755 (K) E from Thomas et al. 7400 (MO) F from Thomas 3204 (MO) G, H from Dinklage 1840 (A) I from Baldwin 10805 (K).

Phenology

Specimens with flowers have been collected in February, April, and May, and with fruits from August to December.

Distribution

(Fig. 34). Collected only along the coast of Liberia, in swamps near sea level.

Additional specimens examined

LIBERIA. Buchanan, 23 Sep 1971 (fr), Adam 26092 (MO); Grand Cape Mount Co., Mecca, 24 Dec 1947 (fr), Baldwin 10805 (K); in fruticetis et ad margines silvarum prope Monrovia et alibi, 20 m, 17 May 1906, Dinklage 1760 bis (B-100153125); Grand Bassa, Dinklage 1840 (A, WU), Grand Bassa, s. d. (st), Dinklage 1858 (A); Grand Bassa, 30 Apr 1898 (fl), Dinklage 1873 (BM, G, P—3 sheets); Grand Bassa, 1 May 1898 (fl), Dinklage either s. n. or 1898—might be 1858 (K); 5 mi N of Bomi Hills, 18 Nov 1970 (fr), Jansen 2255 (WAG); SW Monrovia, 13 Aug 1909 (fr), Massey 49/27 (NY); Monserrado, Firestone Plantation, division 18, ca. 6°24'N, 10°19'W, 11 Feb 1970 (fl), Stoop-v. d. Kasteele, F. S. C. 140 (WAG); without definite locality, s. d. (fr), Straub 290 (US).

Xylopia dinklagei is a shrub or low climber of swampy habitats, with a fine twig pubescence made up exclusively of appressed hairs 0.1–0.3 mm long. The leaf base is often rounded or less often broadly cuneate, and the indument on the abaxial surface of the leaf is not readily visible but is dense, fine, and appressed. The outer petals are only 10.5–13 mm long. The monocarps have a single row of seeds oriented obliquely to the long axis of the monocarp, and the monocarps themselves are usually distinctly torulose, with a thin pericarp, only ca. 0.4 mm thick. The stipe of the monocarp is 6–8 mm long and 2–3 mm thick, and the seeds are oblong to elliptic in cross section. Xylopia dinklagei is superficially similar to X. acutiflora and the species overlap slightly in distribution. Xylopia acutiflora, however, is an upland forest tree reaching at least 15 m in height, with coarser twig pubescence including erect hairs over 1 mm long. Its leaves are cuneate to broadly cuneate at the base, with sparser but longer hairs abaxially. The outer petals are 19.6–37 mm long. The monocarps have two rows of seeds oriented perpendicular to the long axis of the monocarp, and the monocarps are oblong and at most weakly torulose, with a fibrous pericarp ca. 1 mm thick. The stipe of the monocarp is proportionally shorter and thicker than in X. dinklagei, 3–7 mm long and 2.9–4.5 mm thick, and the seeds are wedge-shaped in cross-section.

As in a related climbing species, Xylopia piratae, the ultimate branches on specimens of X. dinklagei are often short (4–7 nodes with ca. 1–3 cm long internodes) and emerge at right angles, with the bases thickened just above where they join the supporting branch.

Engler and Diels based the name Xylopia dinklagei on two Dinklage collections, n. 1760 and n. 1858. The sheets of Dinklage 1760 at B, however, bear different information. One of them, B-100153125, was collected in 1906 from a different locality and therefore cannot be type material. Of the remaining sheets, the two with flower buds (B-100153126 and B-100153127) have labels with the type locality printed on them, but no date information. The collection with mature fruits (B-100249554) is dated 18 October 1896 and is chosen as lectotype. Of the second syntype, Dinklage 1858, only a sheet at A has been seen; this specimen was identified as X. oxypetala by Engler and Diels (1901) but it is more similar to the specimens separated here as X. dinklagei.

Xylopia elliotii Engler & Diels, Monogr. afrik. Pflanzen-Fam. 6: 65. 1901.

Fig. 40

Type

GUINEA [“Sierra Leone”]. Farana Region, riverside woods of Niger, Farana, 26 Mar 1892 (fl), G. F. Scott-Elliot 5325 (lectotype, here designated: B! [100153142]; isolectotypes: BM! [000510796, lower half of sheet], GH! K! [000199071], P! [00169156]).

Description

Shrub or small tree up to 10 (–18) m tall, much-branched; bark gray or dark brown. Twigs reddish brown to dark gray, eventually light gray, densely erect-hairy, the hairs 0.2–0.8 mm long, on new flushes of growth (bud scales still visible at base), eventually glabrate, sometimes with bark exfoliating; nodes commonly with two axillary branches. Leaf with larger blades 4.5–9.5 cm long, 1.8–5.6 cm wide, subcoriaceous, discolorous, lanceolate-ovate to elliptic, oblong, or oblong-lanceolate, apex obtuse, attenuate, emarginate, or acute, occasionally with a short acumen 4 mm long, base cuneate to rounded, short-decurrent on petiole, glabrous except for the pubescent midrib adaxially, finely appressed-pubescent to glabrate abaxially; midrib raised or impressed adaxially, raised abaxially, secondary veins indistinctly brochidodromous, 10–16 per side, diverging at 45–70° from the midrib, these and higher-order veins slightly raised on both surfaces; petiole 3.5–6 mm long, shallowly canaliculate, pubescent. Inflorescences axillary, 1(–2)-flowered, pubescent; pedicels not pedunculate, 3.0–6.1 mm long, 0.9–1.1 mm thick; bracts 2, one to either side of pedicel midpoint, caducous or persistent, 1.6–2.6 mm long, ovate to semicircular, apex acute to obtuse; buds linear-lanceolate, sometimes falciform, apex acute. Sepals slightly spreading at anthesis, 1/4–1/2-connate, 2.3–4.5 mm long, 2.5–3.6 mm wide, coriaceous, ovate to broadly ovate, apex acute or apiculate at the apex, densely sericeous abaxially. Petals white, tinged with purple at the base in vivo; outer petals spreading at anthesis, (12.6–) 19–32 mm long, 2.3–4 mm wide at base, 1.2–2.5 mm wide at midpoint, fleshy, linear, apex obtuse, densely puberulent adaxially, densely appressed-pubescent abaxially; inner petals bent outward from the base at anthesis, 16–24 mm long, 2.3–3.9 mm wide at base, 0.9–1.4 mm wide at midpoint, fleshy, linear, apex acute, base with undifferentiated margin, pubescent on both surfaces, becoming glabrous at base. Stamens ca. 120; fertile stamens 1.1–1.6 mm long, narrowly oblong-clavate, apex of connective 0.2–0.3 mm long, depressed-globose to shieldlike, overhanging the anther thecae, minutely papillate or glabrous, anthers 10–13-locellate, filament 0.2–0.5 mm long; outer staminodes 1.3–1.7 mm long, oblong to clavate, apex acute, obtuse or truncate; inner staminodes 0.8–1.1 mm long, oblong, apex truncate, occasionally innermost stamens reduced in size but still with a few anther locelli so not truly staminodial; staminal cone 1.4–1.8 mm in diameter, 0.6–1.3 mm high, completely concealing the ovaries, rim irregularly laciniate. Carpels 9–10; ovaries 1.3–1.5 mm long, linear-oblong, pubescent, stigmas connivent, 1.3–2.3 mm long, trowel-shaped, apex obtuse, glabrous or pubescent at the apex. Torus flat, 1.9–2.5 mm in diameter. Fruit of up to 8 sparsely pubescent to glabrate monocarps borne on a pedicel 10–12 mm long, 1.3–6 mm thick, glabrate; torus 2.5–16 mm in diameter, 2.5–4 mm high, depressed-globose. Monocarps with red- to purple-tinged green exterior and red endocarp in vivo, 2.0–3.8 cm long, 0.9–1.3 cm wide, 1.1–1.2 cm thick, irregularly oblong or obovoid, slightly torulose, apex rounded, base sessile or contracted into a stipe 3–6 mm long, 2–3 mm thick, slightly wrinkled, finely verrucose and somewhat shiny; pericarp 0.8–0.9 mm thick. Seeds up to 9 per monocarp, in two rows, lying oblique to perpendicular to long axis, 9.2–11.8 mm long, 6.8–7.8 mm wide, 5.3–6.8 mm thick, oblong to flattened-ellipsoid, elliptic to semicircular in cross-section, truncate at micropylar end, rounded at chalazal end, light brown, smooth, dull, raphe/antiraphe not evident, micropylar scar 3.5–4 mm long, 2–2.8 mm wide, broadly elliptic to obovate; sarcotesta unknown in vivo; aril absent.

Figure 40. 

Xylopia elliotii. A Flower, side view, of specimen from Guinea B Flower bud, side view, of specimen from Central African Republic C Flower bud, side view, of isolectotype specimen from Sierra Leone D Seed, view of micropylar end and side view E Fruit F Habit. A from Adam 11846 (MO) B from Le Testu 3787 (P) C from Scott-Elliot 5325 (GH) D from Pobéguin 1529 (P) E from Scott-Elliot 5328 (GH) F from Scott-Elliot 5288 (BM).

Phenology

Specimens with flowers have been collected from January to May, and with fruit from October to March and in May.

Distribution

(Fig. 41). Occurs from northeastern Sierra Leone eastward to Togo, then disjunct to central Cameroon and the Central African Republic, in gallery forest along streams and rivers and occasionally extending into drier uplands, at elevations of 280–1400 m.

Local names

nkankalan jé (Malinké, Duvall 271), ké (Westphal & Westphal-Stevels 10047, 10048, 10049, 10172), kenema (Nongowa, Jordan 2063).

Figure 41. 

Distribution of Xylopia elliotii. Bolder lines represent country borders, fainter lines lakes and major rivers.

Representative specimens

GUINEA BISSAU. Gabú, Pitche, Cambore (Fondo de Cambore), 7 Dec 1955 (yg fr), Explorações Botânicas 3780 (B, FI-T, K, MO, WAG). GUINEA. Beyla, Moribadougou, Apr 1945 (fl), Adam 123 (K, MO, P); Macenta, Tènèmadou, 10 Aug 1949 (st), Adam 5917 (MO); Dalaba, Dalaba, 9 Apr 1956 (fl), Adam 11846 (MO); Chaine de Tibè, 1943 (fr), Adam 26905 (P); Macenta+Beyla Prefectures, Simandou Range, N of Pic de Fon, near the pass on path between villages Moribadou and Lamadou, 8°35'23"N, 8°53'52"W, 1040 m, 27 Mar 2008 (fr), van der Burgt 1167 (K); Fouta Djallon, 23 Apr 1907 (fl), Caille 18149 (P); Macenta+Beyla Prefectures, Simandou Range, Monts Simandou, Pic Dabatini, 8°33'16"N, 8°53'12"W, 1008 m, 23 Mar 2008 (fl), Haba 180 (K); environs de Pita, Jan 1936 (fr), Jacques-Félix 735 (P); Timbo, Mar 1907 (fl, fr), Pobéguin 1529 (P); Lorbé à Pita, May 1909 (fl), Pobéguin 2130 (P); in woods by Niger River, Farana, 26 Mar 1892 (fr), Scott-Elliot 5328 (GH, K); Beyla Prefecture, Tibé Mont., collines SE du Pic de Tibé, en face du village Sondou, 910 m, 8°50'27"N, 8°52'16"W, 10 Dec 2007 (fr), Traoré 35 (K). SIERRA LEONE. Nongawa, Kambui Forest Reserve, Neaboi Valley, 15 Apr 1955 (bud, fl), Jordan 2063 (K, P); Sulimania Road, Falaba Marsh, 24 Mar 1892 (fl), Scott-Elliot 5288 (B, GH, K, P). MALI. 32.8 km SW of Manantali, Arrondissement de Bamafélé, Cercle de Bafoulabé, Région de Kayes, 12°57.009'N, 10°36.613'W, 280-320 m, 12 Nov 1999 (fr), Duvall 371 (MO—4 sheets); near the village of Solo, northern edge of Korofing National Park (formerly Bafing Faunal Reserve), 13°00.362'N, 10°26.137'W, 29 Jan 2004 (st), Duvall 513 (MO); Pilimili Riv. Konnoa, s. d. (fl), Vuillet 68 (P). BURKINA FASO. Tourny (Cascade) (SW Haute Volta), 1 Mar 1971 (fr), Buonounou Ouétien 35 (P). IVORY COAST. Entre Odienné et Sangouani, 1 Mar 1973 (fl), Aké Assi 11969 (K). GHANA. Shiare, Buem-Krachi Dist., 2500’ alt., 18 Apr 1959 (fl), Hall 1450 (K). TOGO. Sakoda, Apr 1905 (fl, old fr ped), Kersting I 84.a (A); without definite locality or date (fl), Kersting A.567 (GH, PH). CAMEROON. W. Cameroons, Ndop Plain, road to French Cameroons, 3800 ft, ca. 6°N, 10°30'E, 30 Mar 1962 (fl), Brunt 261A (K); Mbalang, 16 km E Ngdéré, 27 Jan 1978 (fl), Fotius 2984 (P); Tchal Mbabo, 16 Mar 1978 (fl), Fotius 3108 (P); Bayangam, Jan 1939 (fr), Jacques-Félix 2965 (P); Koutchamkap, Feb 1939 (fl), Jacques-Félix 3039 (P); Adamoua oriental, Hosséré Sillé, 20 Oct 1967 (fr), Jacques-Félix 8724 (P); Tibati, 10 Nov 1967 (fr), Jacques-Félix 9110 (P); Sadolkoulay (36 km E Ngaoundéré), 5 Dec 1964 (fr), Raynal & Raynal 12228 (P—2 sheets); a 20 km E de Foumbot, 5°34'N, 10°48'E, 1100 m, 26 Oct 1974 (fr), Sabatie 15 (MO, P); Près Katil-Foulbe, 50 km SE Ngaoundéré, 20 Oct 1983 (fr), Sabatie 687 (P); Bayangam, 17 May 1978 (fr), Westphal & Westphal-Stevels 10047 (P, WAG—2 sheets); Chutes de Tello, 45 km E de Ngaoundéré, 7°14'N, 13°57'E, 1250 m, 9 Apr 1983 (fl), van der Zon 2105 (WAG). CENTRAL AFRICAN REPUBLIC. Oubangui, Reg Zango, Jan 1920 (fl), Allouette s. n. (L); Chari Oriental (Pays dou Snoussi), [Voyage au Mamoun] Golo près Noellé, 7–28 Mar 1903 (fl), Chevalier 7741 (G, P—2 sheets); Manovo-Gounda-St. Floris National Park, 5 km S of Camp Koumbala along the Koumbala River (8°27'N, 21°13'E), 600 m, 3 Feb 1983 (fr), Fay 4191B (MO); Manovo-Gounda-St. Floris National Park, Koumbala River at Camp Koumbala, 08°29'N, 21°13'E, 590 m, 30 Mar 1983 (fr), Fay 4351 (K), 30 Mar 1983 (fl), Fay 4359 (K); Manovo-Gounda-St. Floris National Park, 9.3 km S of Koumbala Pende confluence on Pende Creek, 8°21'N, 21°14'E, 610 m, 15 May 1984 (fl), Fay 6641 (MO); région de Yalinga, Haut Oubangui, entre Wanda-Djalé et Wadda, 26 Feb 1922 (fl), Le Testu 3787 (BM, P, US); région de la Ouaka, région Ippy, Riv. Monga, 35 km NW Moronbas, 18 Feb 1925 (fl), Tisserant 1778 (BM, P).

Xylopia elliotii is more widespread than has been previously understood but has a number of characteristics consistent across its distribution: it is a small tree of gallery forest, the twigs have a dense indument of erect reddish brown hairs 0.2–0.8 mm long, the abaxial surface of the leaf blade has fine appressed hairs creating a dull surface to the leaf, the pedicels are somewhat elongate and always bear two bracts, one to either side of the pedicel midpoint (Fig. 40A–C), and the monocarps are sessile to short-stipitate with seeds usually in two rows and with a thin pericarp.

The species is largely restricted to the Sudanian biogeographic region (Linder et al. 2012) where few other species of Xylopia occur, but it is not an Upper Guinea endemic as indicated in Holmgren et al. (2004). There is a large disjunction in the distribution between Togo and Cameroon, and specimens from the eastern portion of the range tend to have slightly larger leaves and slightly longer pedicels and outer petals.

The collection McPherson 21337 (MO) from the Nimba Mountains of Guinea is problematic. The leaves and fruit resemble those of other specimens of X. elliotii from Guinea, but the habit, a tree 25 m tall, and the habitat, a forested slope at 860 m, are unusual for the species. The seeds were described as orange. A specimen identified as X. acutiflora in Robson (1960), Holmes H.1273 (K), from the Mwinilunga region of Zambia, also resembles X. elliotii in its reddish-brown erect twig pubescence and relatively long pedicels with only two bracts. The leaves on the specimen, however, are smaller than those of X. elliotii, the tree is described as occurring in mushitu swamp forest, and the specimen is widely disjunct from the range of X. elliotii.

There is little ecological information for Xylopia elliotii. The collections of Fay from Manovo-Gounda-St. Floris National Park, Central African Republic list the following associates in gallery or gallery-associated swamp forests: Adina microcephala, Gardenia imperialis, Ixora brachypoda, Ouratea flava, Rhynchospora corymbosa, Syzygium guineense, and Uapaca togoensis, as well as species of Ancistrophyllum, Berlinia, Cyrtosperma, Gaertnera, Mitragyna, and Raphia. The fragrance of the flowers was noted by several collectors. Two flowers on the collection Fay 6641 (MO) are distorted by galls, similar to those seen in flowers of X. mwasumbii.

Collections made by Westphal and Westphal-Stevels from the area of Bayangam, Cameroon, in 1978 document that the plant is locally kept around houses and the fruits used as a condiment. A collection by Jacques-Félix from the same locality made in 1939 notes that the plant is “cultivé” suggesting a long-standing local use for the fruits of this species.

The protologue for the name Xylopia elliotii Engl. & Diels gives the type locality as Sierra Leone, but Gledhill (1969) has documented that the type locality, Farana on the Niger River, is actually in present-day Guinea.

Xylopia hypolampra Mildbraed, Notizbl. Königl. Bot. Gart. Berlin, Append. 27: 18. [11 Oct] 1913.

Figs 4G, 42E–F

Xylopia brieyi De Wildeman, Bull. Jard. Bot. État 4: 385. 1914. Type. DEMOCRATIC REPUBLIC OF THE CONGO [“Belgian Congo”]. Kongo Central Province, Ganda-Sundi, 8 Oct 1911, J. de Briey 108 (lectotype, here designated: BR! [0000008824844]; isotypes: BR! [0000008824790, 0000008824806, 0000008824813, 0000008824837], US! [1270066]).

Type

CAMEROON. East Region, zwischen Station Lomie, Bidjum und dem Dscha-Posten, 600–700 m, 13 May 1911, J. Mildbraed 5183 (holotype: B!; isotype: HBG! [502479]).

Description

Tree up to 43 m tall, d.b.h. up to 80 cm, bole round, rising to small open crown of horizontal branches; bark brown-gray, smooth, very finely cracked in all directions. Twigs brown, eventually grayish black, tomentellous, the hairs 0.2–0.4 mm long, eventually glabrate; no nodes seen with two axillary branches. Leaf with larger blades 5.7–7.5 cm long, 1.4–1.9 cm wide, subcoriaceous, concolorous, lanceolate, apex attenuate or rarely acuminate, the acumen ca. 12 mm long, and minutely retuse or obtuse, base obliquely cuneate, rarely rounded or somewhat angular, glabrous except for the pubescent midrib adaxially, densely golden- or silvery-sericeous abaxially; midrib plane adaxially, raised abaxially, secondary veins indistinctly brochidodromous, 10–18 per side, diverging at 50–70° from the midrib, these and higher-order veins indistinct adaxially, obscured by indument abaxially; petiole 4–5.5 mm long, semi-terete, pubescent. Inflorescences axillary, 1–3-flowered, pubescent; peduncle absent; pedicels superposed in leaf axil, 2.2–3.8 mm long, 1.0–1.3 mm thick; bracts 3–4, evenly spaced and somewhat imbricate, persistent, 1.8–2.3 mm long, ovate to broadly ovate, apex obtuse to rounded; buds linear, often falciform, apex acute, sometimes uncinate. Sepals slightly spreading at anthesis, 1/3-connate, 2.1–3.2 mm long, 2–2.5 mm wide, coriaceous, broadly triangular, apex acute, pubescent abaxially. Petals pale green to yellow in vivo; outer petals slightly spreading at anthesis, 25–28.7 mm long, 2.5–2.6 mm wide at base, 1.0–1.1 mm wide at midpoint, coriaceous, filiform, apex obtuse and slightly incurved, densely puberulent except for glabrous basal concavity adaxially, sericeous except for a glabrous patch at base abaxially; inner petals more or less erect at anthesis, 16–31 mm long, 1.9–2.5 mm wide at base, 0.6–1.0 mm wide at midpoint, coriaceous, filiform, apex acute, base with undifferentiated margin, longitudinally ridged and puberulent on both surfaces. Stamens ca. 100; fertile stamens 1.0–1.5 mm long, narrowly oblong, apex of connective purplish red in vivo, ca. 0.2 mm long, shieldlike, overhanging anther thecae, minutely papillate, anthers 7–8-locellate, filament 0.4–0.6 mm long; outer staminodes 1.3–1.7 mm long, oblong, apex obtuse to truncate; inner staminodes ca. 1.1 mm long, oblong, apex rounded to truncate; staminal cone 1.3–1.7 mm in diameter, 0.6–0.7 mm high, completely concealing the ovaries, rim laciniate. Carpels 7–12; ovaries 0.7–0.8 mm long, oblong, pubescent, stigmas connivent or sometimes free at the very tips, 1.6–2.5 mm long, filiform, with a tuft of hairs at the apices. Torus flat, slightly concave under the ovaries, 1.5–2.2 mm in diameter. Fruit of up to 8 glabrate monocarps borne on a pedicel 2.5–6 mm long, 3–4.8 mm thick, with the bracts persistent, glabrate; torus 4.5–12 mm in diameter, 3.5–7.5 mm high, depressed-globose. Monocarps with a greenish brown exterior flecked with pale brown lenticels, sometimes tinged with cinnamon or red, and pink-red endocarp in vivo, 2.6–4.1 cm long, 1.1–2.2 cm wide, 1.5–2.1 cm thick, obovoid to oblong or ellipsoid, rarely globose, not torulose, apex rounded, sessile and rounded to truncate at base, often marked by longitudinal ridges but somewhat sunken between them so that the cross-section is bluntly angled, densely lenticellate; pericarp 0.5–1.4 mm thick, fibrous, woody. Seeds up to 10 per monocarp, in two rows, lying perpendicular to long axis, 7.1–10.6 mm long, 6.3–7.9 mm wide, 4.2–5.7 mm thick, elliptic, ovate, oblong or nearly circular, wedge-shaped to semicircular in cross section, truncate at micropylar end but micropylar scar bent to the side, rounded at chalazal end, light reddish brown, smooth, dull, raphe/antiraphe not evident, micropylar scar 1.3–4 mm long, 1.4–2 mm wide, ovate to circular; sarcotesta greenish white in vivo; aril absent.

Figure 42. 

Xylopia pynaertii, X. mildbraedii, and X. hypolampra. A, B X. pynaertii A Habit B Fruit C, D X. mildbraedii C Fruit D Habit E, F X. hypolampra E Habit F Fruit. A from McPherson 13825 (MO) B from Letouzey 12317 (P) C from Breteler et al. 12632 (WAG) D from Reitsma & Reitsma 2816 (NY) E from Le Testu 2023 (F) F from Le Testu 8094 (BM).

Phenology

Collections with flowers have been obtained from November to June, and those with fruits in all months of the year except September; in Lopé National Park, Gabon, a peak of flowering was observed in October and November, followed by production of fruits from June to August (E. Bush and K. Abernethy, personal communication).

Distribution

(Fig. 43). Occurs from central Cameroon east to southwestern Central African Republic and south to the Cabinda Province of Angola and southwestern Democratic Republic of the Congo, where it grows in evergreen or semi-deciduous forest, sometimes along forest edges, and in gallery forest, at elevations of 400–900 m. In the northern Republic of the Congo, seedlings are reported as growing on roadsides (congotrees.rbge.org.uk: Royal Botanic Garden Edinburgh); the report is probably reliable, although we have seen no X. hypolampra specimens from the Republic of the Congo.

Local names

Abiès (Bulu, de Wilde 7963), canzi (Bayaka, LeTestu 1749), ekui (reported as timber trade name, ITTO), lucanga (Murta 43), lukanga ivembuka (lukanga jaune) (Sargos 141), molo-nzange (Lissongo, Tisserant 1246, 1385), ndong-eli np (+ Fang, Wilks WIL 1040), nyanghogha (Mitsogo, Wilks WIL 1040), odjobi (Foury 101), sangi (Babindjere, Harris & Fay 222).

Figure 43. 

Distributions of Xylopia villosa, X. letestui, and X. hypolampra. Bolder lines represent country borders, fainter lines lakes and major rivers.

Additional specimens examined

CAMEROON. Bitya near River Ja, s. d. (fl), Bates 1757 (K); South Province, Department Ocean, Mvie, about 11 km (along a straight line) ENE of village Mvie, 12 km N of Akom II by road, 2°55'N, 10°39'E, 400 m, 28 Jan 1998 (fl), van der Burgt & Laan 364 (K, MO, WAG); Central Division, Gazette: Ndanan 1, near Mefou town, 3°37'29"N, 11°34'56"E, alt. 710 m, 8 Mar 2004 (fr), Cheek 11487 (K); without definite locality, 1935 (fl), Foury 101 (OWU, P); a 30 km au NE de Bange (km 75 route Yokadouma-Moloundou), 25 May 1963 (fr), Letouzey 5139 (P); Bipindi–Ebolowa, Aug or Dec 1913, Mildbraed 7618 (B, K); Dengdeng, Sommer 1914 (buds), Mildbraed 8827 (BM, K—4 sheets); 16 km on the road from Ebolowa to Minkok, 2°58'N, 11°17'E, 670 m, 6 Feb 1975 (fl), de Wilde 7963 (B, BR, K, M, NY, P, U, WAG). CENTRAL AFRICAN REPUBLIC. Sangha Economique Prefecture, Ndakan, gorilla study area, 02°21'N, 16°09'E, 350 m, 13 Feb 1988 (fr only), Harris & Fay 222 (MO); Sangha Economique Prefecture, Ndakan, gorilla study area, 02°21'N, 16°09'E, 350 m, 27 Feb 1988 (fr), Harris & Fay 266 (MO); Sangha Economique Prefecture, Ndakan, gorilla study area, 02°21'N, 16°09'E, 350 m, 21 Mar 1988 (fr), Harris & Fay 319 (MO); Boukoko, 20 Nov 1948 (fl), Tisserant 1246 (K, P); 23 Feb 1949 (fr), Tisserant 1385 [fruit of Tisserant 1246] (P). GABON. Ngounié: St. Martin – Munungu, July 1939 (fl, fr), Walker s. n. or 3454 (BM, K, MO, P); 6 km SSE du village Bilengui, 2°01'S, 11°26'E, 5 Feb 1985 (buds), Wilks WIL 1040 (WAG).—Nyanga: Mayombe Bayaka, région du Nyanga, Inganga, 20 May 1914 (fl), Le Testu 1749 (BM, K, MO, P); Tchibanga, 21 Feb 1919 (fl), Le Testu 2023 (BM, F, MO–-2 sheets, P).—Ogooué-Ivindo: forêt des Abeilles, 40 km SSW of confluence of Ogooué-Ivindo, 00°30'S, 12°02'E, 5 Aug 1993 (fl, fr), Dibata 1171 (K—2 sheets); Bélinga, Mines de Fer, 700–900 m, 4 Jun 1966 (fr), Hallé 3736 (P); Réserve de la Lopé, au sud d’Ayem, chantier SOFORGA, 0°25'S, 11°30'E, 13 Mar 1989 (st), McPherson 13763 (F, MO, NY); ca. 25 km ENE of Booué, 0°02'S, 12°06'E, 18 May 1987 (fr), Reitsma et al. (MO, NY, RSA); Reserve de Lopé-Okanda, west-central region of tourist zone, top of “Point of View” hill, 00°10'47"S, 11°34'48"E, 363 m, 3 Nov 2000 (fr), Stone et al. 3171 (MO); MPAM/Lopé River, Lopé Reserve, 0°15'S, 11°40'E, 16 May 1991 (fl), White LJTW 0483 (MO); road Mékambo to Makokou, 4 km W of Mbela-Baya, 0°58.5'N, 13°52'E, 500 m, 31 Dec 2000 (fl, fr), Wieringa et al. 3748 (WAG).—Ogooué-Lolo: About 30 km E of Lastoursville, 0°40'S, 13°00'E, 19 Nov 1991 (fl, fr), Breteler & Jongkind 10590 (MO, WAG); about 20–40 km NNE of Koumémayong, 0°15'N, 11°55'E, 13 Apr 1988 (fl, fr), Breteler et al. 8669 (WAG); Makande surroundings, about 65 km SSW of Booué, ca. 0°41'S, 11°55'E, 21 Jan 1999 (fr), Breteler et al. 14716 (WAG); région de Lastoursville, 1929–1931 (fl), Le Testu 8094 (BM, BR, K—2 sheets, NY, P, US); km 16 E-most road on chantier 19 branching off 21 km from Lastoursville direction Koula-Moutu, 0°56'S, 12°35'E, 23 Nov 1988 (fr), van der Maesen 5790 (MO, WAG).—Woleu-Ntem: without definite locality, May (fr), Louis et al. 3419 (MO).—Province unknown: Kouilou infr., Sargos 141 (P). DEMOCRATIC REPUBLIC OF THE CONGO. Kongo Central: Luki, 10 Dec 1947 (fl), Donis 1617 (K); INEAC, Luki, Mayumbe Prov. Kinshasa, Terr. Lukula, 27 Mar 1959 (st), Mahieu 292 (WAG), 27 Marh 1959 (fl, fr) Mahieu 293 (WAG); Luki, vallée de la Minkudu à flanc de esteau, 27 Jun 1927 (fl, fr), Toussaint 2395 (K, MO, P, US, WAG); Leopoldville Prov., Boma Territory, Luki, 7 Mar 1955 (fr), Wagemans 956 (K). ANGOLA. Mayombe, Oct–Nov 1921 (st), Dawe 267 (K); Buco Zau, 28 Jul 1916 (fr), Gossweiler 6532 (BM); Mayumbe, Buco Zau, Dec 1916 (fr), Gossweiler 7225 (BM); Cabinda-Chiaca, na Estrada para Buco Zau, 15 Mar 1959 (fl), Murta 43 (BM).

Xylopia hypolampra, with its distinctive narrow coriaceous abaxially sericeous leaves, is readily separable from other African Xylopia species. The pedicels are always short, such that the flowers and fruits appear sessile in the leaf axils. The outer surface of the monocarps at maturity is brown and strongly marked with lenticels, and typically splits into three segments instead of the usual two. The monocarps are often longitudinally ridged and bluntly angled when dry.

Xylopia hypolampra becomes a slender small-crowned canopy tree in forests across its distribution and appears to be locally common. Associates mentioned by collectors include “Sterculiaceae” (two separate collections from Cameroon and Central African Republic), Megaphrynium macrostachyum, Piptadeniastrum africanum, and species of Albizia, Celtis, and Entadophragma. A photograph of flowers (Couvreur 568 from Bélinga, Gabon, Nov 2013), shows a small beetle visiting the flower, but the species could not be determined, nor is it known whether the insect was behaving as a pollinator. Hornbills and, perhaps less frequently, monkeys (ex Harris & Fay 266) feed on the fruits and seeds; at the Dja Preseerve site in Cameroon, hornbills were particularly effective in extending the seed shadow for individual trees (Holbrook and Smith 2000).

Hutchinson (1923) observed the similarity of the leaves of Xylopia hypolampra to those of a number of Neotropical species of the genus such as X. sericea and X. discreta, implying a phylogenetic connection between South American and African species, but recent phylogenetic work has shown that Xylopia hypolampra is not closely related to any tropical American species (Stull et al. 2017).

The original German description of Xylopia hypolampra given by Mildbraed in 1913 makes no mention of a type specimen. A Latin description and citation of a type specimen were provided by Mildbraed and Diels (Bot. Jahrb. Syst. 53: 445, 1915), but in the meantime (1914) the name Xylopia brieyi, a taxonomic synonym for X. hypolampra, was published by De Wildeman. All of these dates precede the requirement for a Latin diagnosis (ICN 2012, Article 39.1) and for citation of a type (ICN 2012, Article 40.1) so the 1913 description constitutes valid publication and the name X. hypolampra with Mildbraed as the sole author is accepted. The holotype for Xylopia hypolampra is extant at B and thus the lectotypification provided by Le Thomas (1969) of a duplicate at HBG was unnecessary.

Xylopia katangensis De Wildeman, Ann. Mus. Congo, Sér. 4, Bot. 1: 32–33. 1902.

Fig. 27L

? Xylopia katangensis var. gillardinii Boutique, Bull. Jard. Bot. État 21: 109–110. 1951. Type. DEMOCRATIC REPUBLIC OF THE CONGO [“Belgian Congo”]. Kasaï Province, vallée du Kasai, Versant, Makumbi, Terr. de Tshikapa, Jan 1938, J. Gillardin 352 (holotype: BR!; isotypes: BR ! [0000008824820], K! [000199055]).

Type

DEMOCRATIC REPUBLIC OF THE CONGO [“Belgian Congo”]. Haut-Katanga Province, Lukafu, May 1900, Ct. E. A. A. Verdick 503 (holotype: BR!).

Description

Tree up to 13 m tall, perhaps taller, d.b.h. up to 60 cm, bole with buttresses at base; bark gray, smooth. Twigs brown to blackish brown, eventually grayish brown to dark gray, sparsely pubescent, the hairs ca. 0.2 mm long, soon glabrate; nodes with two axillary branches occasional. Leaf with larger blades 7.1–9.4 cm long, 2.4–3.3 cm wide, subcoriaceous, slightly discolorous, often shiny blue-green adaxially, whitish green abaxially, lanceolate to lanceolate-elliptic, apex acute to short-acuminate, the acumen 4–11 mm long, base cuneate to broadly cuneate, glabrous on both surfaces, rarely with a few hairs abaxially; midrib slightly raised or plane adaxially, raised abaxially, secondary veins somewhat arcuate, irregularly brochidodromous, 10–15 per side, diverging at 50–60° from the midrib, these and higher-order veins raised to strongly raised on both surfaces; petiole 3.5–9 mm long, shallowly canaliculate, glabrous. Inflorescences axillary or from the axils of fallen leaves, 1–12-flowered, sparsely pubescent to pubescent; peduncles 1–2 per axil, 1–3.5 mm long; pedicels 2–9 per peduncle, 5.7–9.1 mm long, 0.4–0.8 mm thick; bracts 2–4, the upper subtending the sepals and persistent, the lower at or just proximal to pedicel midpoint and caducous, 0.9–1.8 mm long, ovate to semicircular, apex obtuse to rounded; buds linear, occasionally somewhat falcate, apex acute. Sepals slightly spreading at anthesis, 1/5–1/4-connate, 1.6–2.3 mm long, 2.1–3.4 mm wide, subcoriaceous, broadly ovate to triangular, apex acute to obtuse, pubescent abaxially. Petals greenish yellow with red on the adaxial bases in vivo; outer petals spreading at anthesis, 19–37 mm long, 2.7–3.2 mm wide at base, 0.7–1.4 mm wide at midpoint, chartaceous, filiform, apex obtuse, puberulent adaxially, sparsely pubescent abaxially; inner petals slightly bent outward at the base at anthesis, (11.4–) 17.4–29 mm long, 2.3–2.9 mm wide at base, 0.4–0.6 mm wide at midpoint, chartaceous, needle-like, apex acute, base with undifferentiated margin, puberulent on both surfaces except for the glabrous claw. Stamens ca. 90; fertile stamens 1.0–1.1 mm long, oblong, apex of connective 0.1–0.2 mm long, depressed-globose to shieldlike, overhanging the anther thecae, minutely papillate, anthers 7–10-locellate, filament 0.4–0.5 mm long; outer staminodes 1.1–1.2 mm long, clavate, apex truncate to emarginate; inner staminodes ca. 0.9 mm long, clavate, apex truncate; staminal cone 0.7–1.5 mm in diameter, 0.4–1.0 mm high, concealing the lower half of the ovaries, rim irregularly laciniate. Carpels 3–4; ovaries 1.3–1.4 mm long, narrowly oblong, sericeous, stigmas loosely connivent at base with tips free, 2.5–4.4 mm long, linear, glabrous or with a tuft of hairs at the apex. Torus flat, 1.3–1.8 mm in diameter. Fruit of up to 2–4 glabrate monocarps borne on a pedicel 8.4–14 mm long, 1.7–2.5 mm thick, glabrate; torus 2.5–4.4 mm in diameter, ca. 2.3–4.1 mm high, depressed-globose. Monocarps with green exterior and red endocarp in vivo, 1.9–3.4 cm long, 1.2–1.5 cm wide, 0.9–1.0 cm thick, oblong, weakly torulose, apex obtuse, base contracted into a stipe 3.5–4 mm long, ca. 3.0–3.5 mm thick, longitudinally wrinkled, verrucose; pericarp 0.4–1 mm thick. Seeds 1–5 per monocarp, in a single row or in two irregular rows, lying oblique to perpendicular to long axis, 9.3–10.7 mm long, 7.7–7.9 mm wide, 6.7–6.8 mm thick, broadly ellipsoid, broadly elliptic in cross-section, truncate at micropylar end, rounded at chalazal end, brown, smooth or slightly pitted, dull, raphe/antiraphe visible but not raised or sunken, micropylar scar 2.4–2.5 mm long, 2.1–2.4 mm wide, elliptic to circular; sarcotesta gray or light green in vivo; aril absent.

Phenology

Specimens with flowers have been collected in February, March, May, August, October, and November, and with fruits in February, April, May, August, and October.

Distribution

(Fig. 45). Occurs from north-central Nigeria east to central Cameroon and south to Gabon, southern Democratic Republic of the Congo and northeastern Zambia, where it grows in riparian inundated habitats and mushitu swamp forest at elevations of 470–1220 m.

Local names

Likungu (Turumbu, Louis 7886), ogana (Gabonais, Dybowski 129).

Additional specimens examined

NIGERIA. Jos Plateau, Gindiri, 1040 m, 24 Oct 1957 (fl), Hepper 1143 (BR, K, P); Northern Nigeria, Zaria Province, Anara F. R., Kan Gini, 20 Oct 1947 (fl), Keay FHI 20129 (K—2 sheets, OWU spirit collection). CAMEROON. Près de Mbeuga (entre Vos et Akowolinga), 8 Mar 1962 (fl), Letouzey 4498 (K, MO—2 sheets, P). GABON. Bords de l’Ogo[o]ué en fore Achouka, 26 Aug 1895 (fl, fr), Dybowski 129 (P). DEMOCRATIC REPUBLIC OF THE CONGO. Haut-Katanga: Prov. Katanga, station de Keyberg, 8 km SW de Lubumbashi, 23 Mar 1954 (fl), Schmitz 4748 (K, WAG).—Haut-Lomami: Mupulu, récolté à Kaniama galerie Luba, Feb 1938 (fl), Herman 2212 (BR); Mupulu, Kaniama galerie Luba, Feb 1938 (fl), Prignon 4 (BR).—Lualaba: Kisanga, 1220 m, 2 Feb 1979 (buds), Malaisse 9667 (BR).—Tshopo: Yangambi, 1949 (buds), Gilbert 7739 (K, P); Yangambi, 1949 (fl), Gilbert 9060 (K, P); Yangambi, 1949 (st), Gilbert 9344 (K); Yangambi, ca. 470 m, Ile Tutuku, en face du plateau de l’Isalowe, 15 Feb 1938 (fr), Louis 7886 (B, BM, BR, FI-T, K, MO, P, US); en face d’Tsangi, 470 m, 14 May 1938 (fl), Louis 9374 (B, BM, K, MO); en face d’Tsangi, ca. 470 m, 7 Sep 1938 (bud), Louis 11151 (F, NY, RSA). ZAMBIA. River bank Chambezi, 26 Aug 1927 (fr), Bourne 96 (FHO); Kasama, Kasama Luwingu, 3 Sep 1927 (st), Bourne 124 (FHO); Zambezi Rapids, Ikelenge, 2 Nov 2004 (fl), Congdon 673 (K); Kapalala, Kapalala, Luapula R., 16 Apr 1933 (fr), Duff 134/33 (FHO); Luapula R., 29 Oct 1949 (fl), Fanshawe 1423 (K); Lumangwe District, 14 Nov 1957 (fl), Fanshawe F.3989 (BR, K); Central Province, Kasanka National Park, along Musande River near confluence of Musande and Luwombwa Rivers, 12°31'38"S, 30°07'51"E, 1170 m, 17 Nov 1993 (fl), Harder et al. 1918 (MO); Northern Province, Mporokoso District, Mukubwe River, S of Mweru Wantipa, 28 Oct 1949 (fl), Hoyle 1329 (FHO); Nchelenje, L. Mweru, 7 Oct 1961 (fr), Lawton RML768 (FHO, K); Nchelenje, 5 Feb 1962 (fl), Lawton RML830 (FHO); Western Province, Fort Rosebery District, Lake Bangweulu, Lake Bangweulu (island), N end, 20 May 1931 (fr), Stevenson 265/31 (FHO); Western Province, Kawambwa District, at edge of Lake Mweru, near Kafulwe Mission, 4 Nov 1952 (buds), White 3610 (FHO, K).

Xylopia katangensis is similar to X. longipetala, resembling that species in the long and exceedingly narrow petals and the long stigmas, but differing in the proportionately longer petioles, more complex inflorescences with larger numbers of flowers, sepals not reflexed at anthesis, petals sparsely hairy and rigid (without the strip-of-crepe-paper effect), and outer petals narrower at the base, thus not producing a globose flower base. The shiny blue-green upper surface of the leaf is evident on many specimens.

Specimens from Tshopo Province of the Democratic Republic of the Congo, and from Gabon, Cameroon, and Nigeria, do not seem distinguishable from the other material, despite the great geographic separation. In addition to their morphological similarity, all come from similar inundated habitats, including mushitu forest in Zambia and periodically inundated riverbanks elsewhere. The label of Letouzey 4498 describes the habitat as “Abondant dans le rideau forestier fragmentaire, uniquement inondé, sur la berge du Nyong [river], en bordare de la prairie à Echinochloa stagnina,” the latter a grass tolerant of flooding.

The specimen Gillardin 352, the type of Xylopia katangensis var. gillardinii, exhibits a number of small differences from nominate X. katangensis: the leaves are chartaceous and the blades are distinctly decurrent on the petioles, the inflorescences have only one or two flowers and the pedicels are only 3–5 mm long with 3–5 imbricate bracts. The petals of both whorls are shorter than is typical for X. katangensis, the outer ca. 16.5 mm long and the inner ca. 12.5 mm long. We have seen no additional specimens combining this set of characters, but the specimen Letouzey 4498 has some pedicels with 4 bracts, the specimen Fanshawe F.3989 had some pedicels as short as 5.7 mm, and the specimen Keay FHI 20129 has some inflorescences with only one flower and inner petals as short as 11.4 mm. We conclude that X. katangensis var. gillardinii does not merit taxonomic recognition based on current information, but wish to document these points of difference.

Xylopia letestui Pellegrin, Bull. Mus. Hist. Nat. Paris 26: 658. 1920.

Fig. 44

Xylopia letestui var. longepilosa Le Thomas, Fl. Gabon 16: 178 + t. 33, 10–11. 1969. Type. GABON. Ngounié Province, Moumba, Haute Ngounyé, 3 Sept 1926, G. Le Testu 6046 (holotype: P! [00169154]; isotypes: BM! [000511049], BR! [0000008825315], P! [00169153, 00169155]).

Type

GABON. Nyanga Province, Mayombe Bayaka, Tono-Sangama, 9 Aug 1914, G. Le Testu 1760 (holotype: P! [00169125]; isotypes: BM! [000511048], BR! [0000008825322], EA!, K! [000199054], LISC! [000403], P! [00169126, 00169127]).

Description

Tree up to 40 m tall, d.b.h. up to 28.5 cm, bole straight, buttresses narrow and thin, up to 80 cm high and extending up to 50 cm from the trunk, branches horizontal from trunk; bark pinkish beige, with shallow vertical grooves or striations. Twigs initially often lax and sinuous or somewhat zigzag, bearing a sheaf of overlapping new leaves at the apex, reddish-brown, brown or gray, densely covered with hairs 0.4–1.0 mm long, often marked with decurrent ridges from either side of the petiole base, eventually glabrate; nodes occasionally with two axillary branches. Leaf with larger blades 4.7–10.9 cm long, 1.2–2.7 cm wide, subcoriaceous, discolorous, lanceolate to lanceolate-oblong, apex acute, base truncate and often slightly asymmetrical, glabrous or pubescent along the midrib adaxially, sparsely to densely appressed-pubescent abaxially; midrib plane to slightly raised adaxially, raised abaxially, secondary veins brochidodromous, 8–14 per side, diverging at 45–50° from the midrib, these and higher order veins plane or slightly raised adaxially, raised abaxially; petiole 1–2.2 mm long, semi-terete, pubescent. Inflorescences axillary, 1–4-flowered, pubescent; peduncle 1 per axil, ca. 2.5 mm long; pedicels 2 per peduncle or arising directly from the axil, 1.4–6.9 mm long, 1.1–1.2 mm thick; bracts 2, evenly spaced along pedicel, often with lower bract caducous and upper bract persistent, 2.3–6.0 mm long, ovate, deltate, semicircular, or circular, apex acute or sometimes rounded; buds lanceolate to lanceolate-oblong, apex acute to rounded. Sepals spreading at anthesis, 1/4–2/3 connate, 4.2–5.6 mm long, 3.1–3.2 mm wide, ovate to elliptic, apex obtuse to acute, appressed-pubescent abaxially. Petals cream-colored adaxially, becoming red toward the base in vivo; outer petals with position at anthesis not determinable, 13–22 mm long, 3.0–3.7 mm wide at base, 2.3–3.2 mm wide at midpoint, somewhat fleshy, lanceolate-ligulate, linear-lanceolate, or narrowly triangular, apex acute, puberulent along margins and on apex but otherwise glabrous adaxially, densely appressed-pubescent except for two small glabrous patches at the base abaxially; inner petals with position at anthesis not determinable, 10.3–18.1 mm long, 2.4–3.2 mm wide at base, 1.4–1.9 mm wide at midpoint, somewhat fleshy, linear-lanceolate, apex acute, densely appressed-pubescent for distal 1/3, sparsely pilose in center proximal to that and base glabrous adaxially, with tufts of hairs on margin at the widest point of the base, densely appressed-pubescent abaxially. Stamens numerous; fertile stamens 1.3–1.6 mm long, narrowly oblong, apex of connective 0.2–0.3 mm long, depressed-globose to shieldlike, overhanging anther thecae, glabrous, anthers 12–13-locellate, filament 0.3–0.5 mm long; outer staminodes ca. 1.5 mm long, broadly clavate, apex obtuse to truncate; inner staminodes 1.2–1.3 mm long, oblong, apex truncate; staminal cone 1.2–1.6 mm in diameter, 0.9–1.0 mm high, concealing all but the apices of the ovaries, rim laciniate. Carpels 7–10; ovaries 1–1.1 mm long, oblong, pilose, stigmas loosely appressed in lower half with the tips free, 3–3.5 mm long, linear, sinuate, pilose. Torus flat, 1.8–2.0 mm in diameter. Fruit of up to 6 brown-pubescent monocarps borne on a pedicel 5–16 mm long, 5–10 mm thick, this in turn borne upon a leafless branch ca. 15 cm long, glabrate; torus 8–19 mm in diameter, 7–11 mm high, irregularly depressed-globose. Monocarps with green exterior and bright red endocarp in vivo, 2.7–4.5 cm long, 2.1–3.4 cm wide, 2.0–3.5 cm thick, nearly spherical to ellipsoid, not torulose, apex rounded or obtuse, tapered to a sessile base 7–10 mm wide, weakly wrinkled and verrucose; pericarp 5–7 mm thick. Seeds up to 6 per monocarp, in two rows, lying perpendicular to long axis, 15–19 mm long, 8–13 mm wide, 8–10 mm thick, ellipsoid, flattened-elliptic in cross-section, truncate at micropylar end, rounded at chalazal end, brownish white, smooth, dull, raphe/antiraphe not evident, micropylar scar 4.5–5.5 mm long, 4.2–4.8 mm wide, broadly elliptic to nearly circular; sarcotesta grayish white (“glaucous”) in vivo; aril absent.

Figure 44. 

Xylopia letestui. A Seed, view of micropylar end B Seed, side view C, D Habit E Habit including fruit F Fruit, transmedian section showing seed arrangement G Outer petal, adaxial view H Inner petal, adaxial view I Flower bud J Bract, sepals, and staminal cone K Stigma, side view L Staminode, abaxial view M Fertile stamen, abaxial view. A, B, E, F from Breteler et al. 8867 (WAG) C from Hallé 4274 (WAG) D from Leeuwenberg 3073 (WAG) G–I from van der Burgt 1129 (MO) J–M from Le Testu 5975 (BM).

Phenology

Collections with flowers have been made in February and April, and from July to September, and with fruits in January, March, April, November, and December.

Distribution

(Fig. 43). Occurs from Sierra Leone to southwestern Ghana, and from southeastern Nigeria south to southern Gabon and western Democratic Republic of the Congo, growing in lowland wet forests, sometimes secondary forests, on both clay and well-drained sandy soil, at elevations of 50–450 m.

Local name

Canzi (Bayaka, Le Testu 1760).

Additional specimens examined

SIERRA LEONE. Nyagoi Protected Forest, s. d. (fr), King 158 (K). LIBERIA. Sino, Sapo NP, buffer zone, along new logging road, 5°25'N, 08°46.2'W, 29 Nov 2002 (fl buds), Jongkind 5544 (WAG); first part of Babooni road walking in the direction of Sapo NP, 5°31.20'N, 8°37.800'W, 110–140 m, 5 Mar 2009 (fr), Jongkind et al. 8821 (K). IVORY COAST. 55 km ENE of Sassandra, about 15 km N of Fresco, 16 Mar 1959 (fr), Leeuwenberg 3073 (K, P, WAG–3 sheets); Banco, Martineau 227 (P). GHANA. Fure Forest Reserve near Prestea, 15 Dec 1971 (yg fr), Deaw Sp 465 (MO, NY, RSA). NIGERIA. Oban, 1912 (fl), Talbot s. n. (BM). CAMEROON. Southwest Province, Ndian Division, Korup National Park, 5°01'N, 8°48'E, 100 m, 24 Feb 2008 (fl), van der Burgt 1129 (K, MO); East, Department Haut-Nyong, Dja Reserve, Bouamir Research Area, 90 km SE of Akonolinga, 3°11'05"N, 12°47'39"E, 640–700 m, 23 May 1997 (st), Fogiel 2098 (MO); TDC, Sud Cameroun, 26 Nov 1991 (fr), Hallé 4274 (WAG). GABON. 5–10 km E of Saint Germain, E of Okamo River, 11°38’ E, 0°38'N, 20 Apr 1988 (fr), Breteler et al. 8867 (MO, WAG); Bélinga Mines de Fer, 21 Jul 1966 (fl), Hallé & Le Thomas 122 (K, P); Mimongo, Le Testu 5975 (BM); Woleu-Ntem, Mbe National Park, Monts de Cristal, Tchimbele Dam area, 00°37'02"N, 10°24'49"E, 400 m, Apr 2004 (st), SIMAB 012002 (MO); Woleu-Ntem, Monts du Cristal, 10 Sep 2001 (st), Nguema 341 (MO). REPUBLIC OF THE CONGO. Chaillu, region de Komono, route de Mbila, forêt des environs du village Mitoko, 24 Jan 1977 (fr), Sita 4081 (P). DEMOCRATIC REPUBLIC OF THE CONGO. Équateur: Terr. Bikoro, route Weti-Iboko, 16 Apr 1959 (fl), Evrard 6189 (K).

The nearly sessile leaves with truncate bases, the short inner petals bearing conspicuous basal hair tufts, and the thick-walled globose monocarps readily distinguish Xylopia letestui from its congeners. It is similar to X. villosa, both being large trees with narrow buttresses, leathery leaves that are appressed-pubescent beneath, and relatively large thick-walled monocarps. In addition to the truncate leaf bases and the hair tufts on the outer petals, X. letestui differs from X. villosa in having abaxial leaf indument that is dull-colored, not golden-sericeous, and four or fewer flowers in the inflorescences. The sinuous young shoots with conduplicate new leaves sometimes seen in X. letestui have not been noted in specimens of X. villosa. The presence of X. letestui in West Africa was previously unreported (Keay 1954–1958, 1989, Holmgren et al. 2004), probably in part due to its similarity to X. villosa, which occurs over much of the same range. Associates listed on herbarium labels include Alstonia boonei, Dichostemma glaucescens, Podococcus barteri (understory), Santiria trimera, Tabernaemontana crassa, Terminalia superba, and Uapaca guineensis.

Le Thomas (1969) distinguished two specimens from Gabon with longer and denser indument as a separate variety, X. letestui var. longepilosa. We found density and length of hairs to vary over the range of the species, and that the densest hairs seem to accompany specimens bearing new flushes of growth, suggesting that the characteristic is variable and does not merit taxonomic recognition.

The label of Leeuwenberg 3073 describes the specimen as being from a large liana about 25 m high, but this growth form has not been corroborated by any other specimen data, all of which describe the plant as an erect forest tree.

Xylopia longipetala De Wildeman & T. Durand, Ann. Mus. Congo, Sér. 2, Bot. 1(1): 4. 1899.

Figs 3E, 27A–F, 28B

Uvaria parviflora A. Richard in Guillemin, Perrottet, & A. Richard, Fl. Senegamb. tent., part 1, 9 + t. 3, fig. 1. 1831.

Coelocline ?