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Flora of Cameroon – Annonaceae Vol 45
expand article infoThomas L. P. Couvreur§|, Leo-Paul M. J. Dagallier, Francoise Crozier, Jean-Paul Ghogue|, Paul H. Hoekstra§, Narcisse G. Kamdem|, David M. Johnson#, Nancy A. Murray#, Bonaventure Sonké|
‡ Univ Montpellier, Montpellier, France
§ Naturalis Biodiversity Center, Leiden, Netherlands
| Université de Yaoundé I, Yaoundé, Cameroon
¶ Green Connexion, Yaoundé, Cameroon
# Ohio Wesleyan University, Delaware, United States of America
Open Access

Abstract

Annonaceae is a major pantropical family with 113 genera and about 2550 species. Cameroon is one of the most biodiverse countries in Africa but its flora remains incompletely known. In this volume of the Flora of Cameroon, we describe 166 native taxa representing 163 species in 28 native genera within the family Annonaceae. A total of 22 species (about 13%) are endemic to the country. We provide keys to all native genera, species, and infraspecific taxa. For each species a detailed morphological description and a map of its distribution in Cameroon are provided. Distribution maps and diversity analyses are based on a taxonomically verified database of 2073 collections. Across Africa, Cameroon is a center of diversity for Annonaceae harboring one of the highest numbers of species and genera. For example, Cameroon harbors the highest number of African species for the only pantropical genus of Annonaceae, Xylopia. Annonaceae are found across all 10 administrative regions of Cameroon but diversity is concentrated within the tropical rain forest areas situated in the south and South-West. The areas around Bipindi and Mount Cameroon show the highest levels of diversity, but this is correlated with collection effort. Line drawings and/or photographs accompany most species. One species new to science Uvariopsis etugeana Dagallier & Couvreur sp. nov. is described. We also undertake a number of nomenclatural changes such as lectotypifications, six new synonymies and two new combinations (Uvaria anisotricha (Le Thomas) Couvreur, comb. nov.; Uvariodendron fuscum var. giganteum (Engl.) Dagallier & Couvreur, comb. nov.).

Résumé

Les Annonacées sont une grande famille pantropicale avec 113 genres et 2550 espèces. Le Cameroun est l’un des pays les plus riches en biodiversité d’Afrique mais sa flore reste incomplètement connue. Dans ce volume de la Flore du Cameroun, nous décrivons 166 taxons représentant 163 espèces dans 28 genres au sein de la famille des Annonaceae. Au total, 22 espèces (environ 13%) sont endémiques du pays. Nous fournissons une clé de tous les genres et espèces et des infra-espèces au sein des genres. Pour chaque espèce une description morphologique détaillée et une carte de sa répartition au Cameroun sont fournies. Les cartes de distribution et les analyses de diversité sont basées sur une base de données taxonomiquement vérifiée de 2073 collections. À travers l’Afrique, le Cameroun est un centre de diversité pour les Annonacées abritant l’un des plus grands nombres d’espèces et de genres. Par exemple, le Cameroun abrite le plus grand nombre d’espèces africaines pour le seul genre pantropical d’Annonaceae, Xylopia. Les Annonaceae sont présentent dans les 10 régions du Cameroun, mais la plus grande diversité est concentrée dans les régions abritant la forêt tropicale humide située au sud et au sud-ouest. Les zones autour de Bipindi et du Mont Cameroun présentent les niveaux de diversité les plus élevés, mais cela est corrélé à l’effort de collecte. Des dessins et/ou des photographies accompagnent la plupart des espèces. Une espèce nouvelle pour la science Uvariopsis etugeana Dagalier & Couvreur sp. nov. est décrite. Nous entreprenons également un certain nombre de changements nomenclaturaux tels que des lectotypifications, six nouvelles synonymies et deux nouvelles combinaisons (Uvaria anisotricha (Le Thomas) Couvreur, comb. nov.; Uvariodendron fuscum var. giganteum (Engl.) Dagalier & Couvreur, comb. nov.).

Keywords

Africa, botanical identification, conservation, diversity, lectotypification, new species, taxonomy, vascular plants

Introduction

Annonaceae is a large pantropical family of trees, shrubs and lianas (Keßler 1993; Chatrou et al. 2012). Across Africa, and in Cameroon in particular, Annonaceae play an important role both in terms of species diversity and individual density (Kenfack et al. 2007; Sonké and Couvreur 2014). The famous French botanist André Aubréville (1897–1982) said of Annonaceae that they are among the families that best characterize floristically tropical rain forests in Africa (Aubréville 1970). Just over 50 years ago, Annick Le Thomas published the Annonacées (n°16) in the series Flore du Gabon (Le Thomas 1969b), a foundational treatment that served and continues to serve as the basis for Annonaceae identification across Africa together with other floras from other regions (Boutique 1951b; Robson 1960; Paiva 1966; Verdcourt 1971a; Hawthorne and Jongkind 2006). Our knowledge of African Annonaceae has increased during the last 15 years, with numerous taxonomic revisions being published (Versteegh and Sosef 2007; Couvreur 2009, 2014; Botermans et al. 2011; Fero et al. 2014; Ghogue et al. 2017; Gosline et al. 2018; Johnson and Murray 2018; Hoekstra et al. 2021). This, together with extensive field work across the country over the years, has provided a wealth of information that has allowed the compilation of the present work.

Material and methods

Morphological data matrix and species descriptions

Morphological species descriptions were automatically generated before manual checking and editing. We used the online collaborative platform PROTEUS (Sauquet 2016). This platform allows data and the source or citation of the data to be entered, permitting traceability of the information. We constructed a list of general morphological characters we wanted to use in the species descriptions. This set of characters works for most species, however, manual editing was needed for some genera, in particular for those with non-bisexual species, where different measurements were needed for male, female and/or bisexual inflorescences and flowers.

Data was gathered from two main sources. First, we used all available taxonomic revisions of African Annonaceae genera (e.g. Chatrou 1998; Couvreur 2009; Johnson and Murray 2018) or floras (e.g. Boutique 1951b; Le Thomas 1969b) to gather data on measurements and morphological characters. In most cases, these data were also checked and re-measured on herbarium specimens. Second, we made additional measurements for species without available taxonomic descriptions and of characters not mentioned in available sources. In several cases, measurements were taken from high quality scans of type material available on JSTOR (https://plants.jstor.org/). For all species, we tried to provide a rough estimate of the total number of stamens. When not explicitly reported in prior studies (e.g. Xylopia, Johnson and Murray 2018), these were counted either using photographic material or on herbarium specimens. Stamen numbers were estimated when species had more than 50 stamens per flower; in a few cases where an estimate was not possible they were termed “numerous”. For some species a detailed count was undertaken by Meinke (2008).

A first draft of descriptions for all species was generated using the package MonographaR (Reginato 2016) under the R environment. This assured that descriptions were always parallel. Some characters are repeated across individual species descriptions even if they are constant across the genus (e.g. habit, number of perianth whorls). This deviates from the main approach in taxonomic species descriptions. However, it was adopted here because it allows easier extraction of trait data by outside sources. Indeed, by providing a full description of a species (with all variable or important constant characters) one does not have to search for constant character information in different descriptions (genus or family). For each species, a final description was then prepared. For some genera, we added characters not found in other genera because they were important for identification. For example, the color of the sarcotesta in Xylopia was added because it is a useful character, generally not present or reported in other Annonaceae genera. The same goes for Monanthotaxis or Uvaria (pubescence of young foliate branches). Descriptions for non-bisexual species also deviated slightly from the rest of the descriptions in order to accommodate the description of the male, female and/or bisexual flowers within species.

Cameroonian collection database

A database of Annonaceae collections from Cameroon was generated in which we recorded collector number, location, coordinates, region and herbarium where the specimens are deposited. A collection represents a herbarium sample identified by having the same collector and number (when present). It may be composed of one or more specimens, and such duplicates can be deposited in different herbaria. We used several sources as primary data providers to build the database. The initial database was based on data extracted from the “Réseau Informatique des Herbiers d’Afrique” (RIHA). This database contains all specimens held in the Herbier National du Cameroun/National Herbarium of Cameroon. We extracted all Annonaceae from Cameroon. We then supplemented this database with other available databases: BRAHMS (Naturalis Biodiversity Center, Leiden, The Netherlands); TROPICOS (Missouri Botanical Garden, St Louis, USA); Kew Database (Royal Botanical Gardens, Kew, UK) and other databases (T.L.P. Couvreur (IRD); V. Droissart (IRD); D.J. Harris (E); N. Kamdem (Université de Yaoundé I)). As much as possible specimens were checked in herbaria to confirm their identification. Thus, the database contains specimens that we have seen and confirmed, and others which we did not see. For genera with recent taxonomic revisions, determinations were updated (Chatrou 1998; Versteegh and Sosef 2007; Couvreur 2009, 2014; Botermans et al. 2011; Fero et al. 2014; Ghogue et al. 2017; Gosline et al. 2018; Johnson and Murray 2018).

Collections without coordinates were georeferenced using QGIS ver. 3.2.3 (QGIS Development Team 2019) and the IGN maps for Cameroon or the online gazetteer Geo-Locate (http://geo-locate.org/). Distribution maps were then generated using the package ‘MonographaR’ (Reginato 2016) under the R environment using a modified script of the ‘mapBatch’ function. A shapefile containing the outline of the Cameroon border and all ten regions was used (regions are the highest administrative divisions in Cameroon, formerly known as “provinces”, but changed to “regions” in 2008). In addition, we used a shape file of protected areas across Cameroon. These include Faunal Reserves, Flora Sanctuaries, National Parks, Ramsar Sites (wetlands of international importance), UNESCO Biosphere Reserves and Wildlife Sanctuaries. A shape file of these protected areas was downloaded from the https://www.protectedplanet.net/ on the 28th of April 2020 and filtered for the country Cameroon. A list of these protected areas is available in Suppl. material 1: Fig. S1.

Herbaria visited and field work

Within this project, numerous herbaria were visited over the course of the last eight years including B, BR, BRLU, G, K, P, YA and WAG. Within the taxonomic revision of certain genera, specimen loans were made available from other herbaria (BM, MO, OWU). In addition, we used specimen scans available online from these different herbaria when possible and needed. Numerous field trips were carried out across Cameroon over a period of eight years (2012–2019), mainly in the regions Central, East, Littoral, South West and West regions. During these field trips, high quality herbarium collections were made and deposited at MPU, YA and WAG. Finally, detailed photographs of the different parts available (leaves, trunk, flowers and fruits) were made and used to illustrate species found within this flora.

Diversity maps

The database was used to generate collection, species and genus raw diversity maps. Collection density was log transformed before plotting. After filtering for unidentified species and genera, raw diversity maps were made at 0.25° resolution sampling units (SU) were plotted using the ‘ggplot2’ package (Wickham 2011). Finally, a Shapiro-Wilk’s (for non-normal data) correlation test was done between number of collections and species per 0.25 sampling unit using ‘ggscatter’ function in ‘ggplot2’.

Collection citations

Collection citations and the index to numbered collections were generated using the package ‘exsic’ (Simon and Spooner 2013) under the R environment. For species with more than 30 collections, a subsample of these collections is listed after each species (“Selected specimens examined”). In this case, we cited at least one collection per region where the species is known to occur. Alternatively, the section “Specimens examined” lists all specimens seen by at least one of the authors or identified by a known Annonaceae specialist. When several herbaria are cited after each specimen, we do not indicate what individual specimen we saw, but assume they are deposited in the cited herbaria. All collections and our latest identifications are listed in “indexed number of collections” section (see Appendix 1).

Line drawings

As much as possible we tried to use the original line drawings drawn by Hélène Lamourdedieu, intended by Annick Le Thomas for this flora. Thanks to Thierry Deroin, we had access to her archives at the Muséum national d’Histoire Naturelle in Paris, where we found numerous line drawings not published in the Flore du Gabon. The numbering of drawings was retained when possible. In some cases, specimens used for drawing a specific species changed (new identification). In other cases drawings came from more recent taxonomic revisions.

IUCN Conservation status

The IUCN conservation status of each species was downloaded from the IUCN Red List website (www.iucnredlist.org). Official IUCN published evaluations are provided here, except for the genus Monanthotaxis where the preliminary status were taken from Hoekstra et al. (2021) and cited as “Preliminary”. Otherwise, the mention “not evaluated” is indicated. Most African Annonaceae tree species evaluations were undertaken by Ariane Cosiaux as part of the IUCN SSC Global Tree Specialist Group objectives. Thus, most liana species do not have published conservation statuses yet. For each evaluation the citation is provided. Assessments were downloaded on 29th May 2020 from https://www.iucnredlist.org/ filtering on Annonaceae and Cameroon (and updated on 1st May 2022).

Results

Diversity

We document a total of 28 native genera, 167 native taxa and 163 native species of Annonaceae in Cameroon (Table 1). One species has two subspecies (Annona senegalensis) and three species (Artabotrys aurantiacus, A. insignis, Uvariodendron fuscum) have two varieties. Uvaria muricata is only known to date by the variety yalingensis in Cameroon. The most diverse genus is this flora is Monanthotaxis (a genus of lianas) with 31 species, followed by Xylopia (a genus of mainly trees) with 22 species, while eight genera are known by only one species (Table 1). Just over half of all genera have more than 50% of their species diversity in Cameroon, and for five genera Cameroon harbors 100% of the known species (Table 1). Cameroon is a center of diversity for four genera with more than 10 species: Monanthotaxis (39% of the diversity), Uvariopsis (68% of the diversity), Piptostigma (100% of the diversity) and Xylopia (49% of the African diversity). No genus is endemic to Cameroon, but 22 (~13%) species are endemic to the country (Table 2).

Table 1.

List of number of 28 native genera recorded for Cameroon plus 12 continental African genera not found in Cameroon, with known accepted number of species in Cameroon, for continental Africa (including the Gulf of Guinea Islands, but excluding Madagascar) and percentage of species for each genus found within Cameroon. Total species diversity numbers were taken from Guo et al. (2017b) for endemic continental African genera, and from the African Plant Database for non-endemic genera (Artabotrys, Uvaria). For Isolona continental diversity was taken from Couvreur (2009), Mischogyne from Gosline et al. (2018) and Xylopia from Johnson and Murray (2018). 1Afroguatteria, Monanthotaxis and Sphaerocoryne include species formally placed in Friesodielsia; 2Neostenanthera includes Boutiquea.

Genus Number of species in Cameroon Number of species in continental Africa Percentage in Cameroon
Afroguatteria1 1 3 33
Annickia 4 8 50
Annona 1 4 25
Anonidium 2 4 50
Artabotrys 8 32 25
Brieya 1 2 50
Cleistopholis 3 3 100
Dennettia 1 1 100
Duguetia 4 4 100
Greenwayodendron 2 5 40
Hexalobus 4 5 80
Isolona 9 15 60
Letestudoxa 2 3 67
Meiocarpidium 1 1 100
Mischogyne 1 5 20
Monanthotaxis1 31 79 39
Monodora 6 14 43
Neostenanthera2 3 5 60
Piptostigma 13 13 100
Polyceratocarpus 3 8 38
Sirdavidia 1 1 100
Sphaerocoryne1 1 2 50
Toussaintia 1 4 25
Uvaria 17 77 23
Uvariastrum 3 5 60
Uvariodendron 5 18 28
Uvariopsis 13 19 68
Xylopia 22 45 49
Asteranthe (3), Cleistochlamys (1), Dielsiothamnus (1), Huberantha (4), Lettowianthus (1), Lukea (2), Mkilua (1), Monocyclanthus (1), Mwasumbia (1), Ophrypetalum (1), Pseudartabotrys (1), Sanrafaelia (1). 0 19 0
Total : 163 399 41
Table 2.

List of the 22 endemic species of Annonaceae recorded for Cameroon.

Genus Species epithet Author(s)
Afroguatteria discostigma (Diels) X.Guo & R.M.K.Saunders
Artabotrys dielsiana Le Thomas
Hexalobus bussei Diels
Monanthotaxis couvreurii P.H.Hoekstra
Monanthotaxis dielsiana (Engl.) P.H.Hoekstra
Monanthotaxis elegans (Engl. & Diels) Verdc.
Monanthotaxis hexamera P.H.Hoekstra
Monanthotaxis submontana P.H.Hoekstra
Monanthotaxis zenkeri P.H.Hoekstra
Monodora zenkeri Engl.
Piptostigma goslineanum Ghogue, Sonké & Couvreur
Piptostigma longepilosum Engl.
Piptostigma macrophyllum Ghogue, Sonké & Couvreur
Piptostigma mayndongtsaeanum Ghogue, Sonké & Couvreur
Piptostigma submontanum Ghogue, Sonké & Couvreur
Uvaria mollis Engl. & Diels
Uvariopsis dicaprio Gosline & Cheek
Uvariopsis etugeana Dagallier & Couvreur
Uvariopsis korupensis Gereau & Kenfack
Uvariopsis sessiliflora (Mildbr. & Diels) Robyns & Ghesq.
Uvariopsis submontana Kenfack, Gosline & Gereau
Uvariopsis zenkeri Engl.

Annonaceae distribution and diversity in Cameroon

A total of 2073 collections were seen for this treatment (Fig. 1A). Of these 1973 were identified to species level or below, while 17 were only identified as Annonaceae sp. These were mainly sterile collections. The dataset used is available on the GBIF platform (https://www.gbif.org/dataset/b738ab95-44a3-4d51-9ac6-3c0971e23a6f and has the DOI: https://doi.org/10.15468/ewp59s).

Figure 1. 

Distribution of Annonaceae collections in Cameroon. Based on 2803 georeferenced collections (out of 2857), including undetermined ones. Map represents Cameroon with regional borders (Admin 1 level). Altitude is given in meters.

Annonaceae have been collected from all 10 regions in Cameroon, but most sampling comes from the southern regions of the country (Fig. 1A, B) with the South Region having the highest number of Annonaceae collections while the Far-North had the fewest (most diverse: Littoral Region: 139; Central Region: 264; East Region: 258; South Region: 631; South-West Region: 612; Fig. 1A, B). The highest number of collections for a single SU is 155 (around Bipindi; Fig. 1B) and the mean number of collections per SU is 9.2.

In terms of species diversity, there are two main hotspots, one located in the SU around Bipindi in the northwestern South Region (with 46 species recorded), and one in the SU around Mount Cameroon in the South-West region (with 40 species recorded) (Fig. 2B). Regions of high Annonaceae species diversity are mainly located in the Atlantic forests (around Yaoundé, southern Cameroon Volcanic Line, and western South region (Bipindi, Kribi, Campo) (Letouzey 1968), and to a lesser level in the southern part of the East region (Fig. 2A, B). Species diversity is significantly correlated with collection density (Spearman’s Rank: Rhospecies = 0.98, Rhogenus = 0.97; P < 0.001).

Figure 2. 

Spatial diversity of Annonaceae in Cameroon A log transformed collection density B raw species diversity C raw generic diversity D scatter plot of number of species in function of collections per SU, with correlation parameter R and p value. Maps represent Cameroon with limits between regions. Sampling units (SU) are of 0.25.

Genus diversity is also concentrated in the Atlantic forests, with hotspots along the Cameroonian Volcanic Line, and towards the western area of the South region. Once again, the SU around Bipindi has the highest generic diversity with 19 (mean: 3.6 genera / SU) recorded genera (Fig. 2A). Genus diversity is also significantly correlated with collection density (Spearman’s Rank: Rhogenus = 0.97; P < 0.001).

Xylopia is the most collected genus across Cameroon (277 collections), followed by Monanthotaxis (196 collections) (Table 3), while the genera Sirdavidia and Toussaintia are only known by a single Cameroonian collection to date. Greenwayodendron suaveolens is the most collected species (119 collections, Fig. 3A), almost twice as many as the next five most commonly collected species (Table 3, Fig. 3A). Finally, 18 species are known from a single collection, 102 species are known from 10 or fewer collections, and five are known from 50 or more collections (Fig. 3A).

Table 3.

Number of collections for all 28 genera recorded in Cameroon and for the top 27 species. Values based on collections between 1861 and 2019.

Genus # specimens Species # specimens
Xylopia 277 Greenwayodendron suaveolens 119
Monanthotaxis 196 Annickia affinis 60
Uvariodendron 165 Uvariodendron connivens 60
Monodora 156 Monodora myristica 54
Uvariopsis 135 Anonidium mannii 53
Greenwayodendron 134 Xylopia aethiopica 45
Piptostigma 126 Monanthotaxis enghiana 43
Artabotrys 119 Meiocarpidium oliverianum 42
Uvaria 115 Xylopia thomsonii 41
Isolona 80 Monodora undulata 36
Annickia 73 Monodora tenuifolia 34
Neostenanthera 62 Xylopia quintasii 32
Anonidium 59 Uvariodendron molundense 31
Hexalobus 53 Neostenanthera neurosericea 30
Cleistopholis 46 Xylopia africana 30
Annona 44 Artabotrys aurantiacus 28
Uvariastrum 44 Neostenanthera myristicifolia 28
Meiocarpidium 42 Uvariodendron calophyllum 28
Duguetia 40 Annona senegalensis subsp. oulotricha 25
Polyceratocarpus 33 Hexalobus crispiflorus 25
Sphaerocoryne 20 Uvariodendron fuscum 24
Brieya 15 Uvariastrum zenkeri 22
Dennettia 7 Uvariopsis dioica 22
Letestudoxa 6 Polyceratocarpus parviflorus 21
Afroguatteria 4 Sphaerocoryne gracilipes 20
Mischogyne 3 Uvariopsis bakeriana 20
Sirdavidia 1 Artabotrys thomsonii 19
Toussaintia 1 Duguetia staudtii 19
Figure 3. 

Sampling history of Annonaceae in Cameroon A ranked number of collections (specimens) per taxa (including subspecies and varieties) B cumulative number of Annonaceae collections (specimens) through time from 1861 to 2019 C cumulative number of Annonaceae species through time from 1861 to 2019. This graph is based on 2060 herbarium collections (with known year of collection)

IUCN Conservation status

A total of 95 species received a conservation status from the International Union for the Conservation of Nature, IUCN. However, we excluded the species Uvariodendron fuscum which now also includes formerly distinguished taxa (U. mirabile and U. giganteum) and thus would need to be reassessed. In addition, the name Boutiquea platypetala is considered here to be a synonym of Neostenanthera neurosericea. We nevertheless used the available assessment of B. platypetala because N. neurosericea is only known from the type specimen (single location), and this nomenclature change does not affect the assessment. Thus, just over half (94 species) of the Cameroonian species have an official IUCN conservation assessment to date. Of these, only two are liana species (Uvaria angolensis, U. chamae). Two species were evaluated using old criteria (version 2.3 and were published before 2000). Of the 94 species considered, 24 (Table 4) are evaluated as Threatened (25.5% of 94 species assessed): none are Critically Endangered, 10 are Endangered (10.6%) and 14 are Vulnerable (15%). Finally, two species are considered as Near Threatened (NT, 2.1%) and one as Data Deficient (DD, Xylopia talbotii; 1%). Piptostigma has the highest number of threatened species of any genus with seven (and one as NT), followed by Xylopia with five (and one as DD) (Table 4).

Table 4.

List of the 24 Annonaceae species occurring in Cameroon officially assessed (and published) as Threatened following IUCN criteria. The assessment of Neostenanthera neurosericea is based on Boutiquea platypetala which is now a synonym of the former. Uvariopsis pedunculata was assessed under the former name U. vanderystii.

Genus and species epithet Red list category Red list criteria Year published Criteria version
Duguetia dilabens Endangered B2ab(iii,v) 2020 3.1
Hexalobus bussei Endangered B1ab(ii,iii,iv)+2ab(ii,iii,iv) 2019 3.1
Isolona pilosa Vulnerable B2ab(iii) 2019 3.1
Isolona pleurocarpa Endangered B2ab(iii) 2019 3.1
Mischogyne gabonensis Endangered B2ab(i,ii,iii,iv,v) 2021 3.1
Neostenanthera neurosericea (as Boutiquea platypetala) Vulnerable B2ab(iii) 2014 3.1
Piptostigma calophyllum Vulnerable B2ab(iii) 2019 3.1
Piptostigma giganteum Vulnerable B1+2c 1998 2.3
Piptostigma goslineanum Vulnerable B1ab(iii)+2ab(iii) 2019 3.1
Piptostigma longepilosum Endangered B2ab(iii,v) 2019 3.1
Piptostigma macrophyllum Vulnerable B2ab(iii,iv) 2019 3.1
Piptostigma oyemense Vulnerable B2ab(iii) 2019 3.1
Piptostigma submontanum Endangered B1ab(iii)+2ab(iii) 2019 3.1
Sirdavidia solannona Vulnerable D2 2019 3.1
Uvariodendron giganteum Vulnerable B2ab(iii) 2004 3.1
Uvariopsis korupensis Endangered B2ab(iii) 2014 3.1
Uvariopsis submontana Endangered B1ab(iii)+2ab(iii) 2014 3.1
Uvariopsis pedunculata Vulnerable B2ab(iii) 2014 3.1
Uvariopsis zenkeri Vulnerable B2ab(i,ii,iii,iv,v). 2021 3.1
Xylopia africana Vulnerable A2c 2014 3.1
Xylopia calva Endangered B2ab(iii) 2019 3.1
Xylopia gilbertii Vulnerable B2ab(iii) 2019 3.1
Xylopia mildbraedii Vulnerable B2ab(iii) 2019 3.1
Xylopia paniculata Endangered B2ab(iii) 2019 3.1

Based on preliminary conservation assessments (Hoekstra et al. 2021), the liana genus Monanthotaxis has more than half of its species assessed as threatened (16/31). Four of these are Critically Endangered (CR), nine are Endangered (EN) and three are Vulnerable (VU).

Discussion

Diversity and distribution

Cameroon is a diversity hotspot for Annonaceae (Table 1). We recognize 28 native genera out of the 39 known (see Table 1) in continental Africa or ca. 72% of the total (excluding the two endemic genera from Madagascar, Ambavia and Fenerivia). The total number of genera cited above and in Table 1 includes the newly described genus Lukea Gosline & Cheek (with two species) from Tanzania and Kenya (Cheek et al. 2021). We here synonymize the genus Boutiquea with Neostenanthera, while all the African species of Friesodielsia were recently reassigned to three different genera, i.e. Afroguatteria, Monanthotaxis and Sphaerocoryne (Guo et al. 2017b). Most of the African genera not present in Cameroon are monotypic and occur in East Africa (e.g. Lukea, Mkilua, Mwasumbia, Lettowianthus, Sanrafaelia), Gabon (Pseudartabotrys) or West Africa (Monocyclanthus). In terms of species diversity, Cameroon harbors about ca. 41% (163 out of ca. 400 species) of the family’ continental species (estimated in Table 1). In terms of Annonaceae species diversity, Cameroon is the most species-rich country of continental Africa. Gabon, for example has 139 recorded species (Sosef et al. 2006) - the Flore du Gabon describes just 119 species (Le Thomas 1969b) but over the last 50 years, several new species or genera have either been described (Jongkind 2002; Couvreur et al. 2015; Couvreur and Niangadouma 2016; Hoekstra et al. 2021) or found to occur in Gabon (Lachenaud et al. 2018), so diversity is higher. Annonaceae represent almost 2% of the Cameroonian flora, which is estimated to harbor around 8000 species (Onana 2011; Sosef et al. 2017).

The increase of Cameroonian Annonaceae specimens or species through time has not been constant (Fig. 3B, C; see also Stropp et al. 2016). This discovery dynamic is similar to the one described for Gabon based on specimens for all plant families (Lachenaud et al. 2018). We can identify two main periods of important Annonaceae discovery: 1895 to 1915 and to a lesser extent 1960 to 1977. The first Annonaceae herbarium specimens documented for Cameroon were collected by the German botanist Gustav Mann (1836–1916) between 1861 and 1862. After that, few collections were made for over 30 years. Then, several German botanists started intensive collecting, in particular Gottfried Wilhelm Johannes Mildbraed (1879–1954) and Georg August Zenker (1855–1922). Zenker arrived in 1889 and was posted in Yaoundé, before moving to the village of Bipindi (South Region), at the base of the Ngovayang mountain range where he spent the rest of his life. This early botanical exploration explains the first strong increase in Cameroonian Annonaceae species starting in 1895 and ending in 1915 (Fig. 3B). The second most important period of Annonaceae discovery started around 1960 and coincided with two main events. First, this was the time when René Letouzey (1918–1989), a French botanist based at the Herbier National du Cameroun in Yaoundé, was active collecting specimens across the country. Second, is the period when Dutch botanists from the Wageningen Herbarium, in particular Jan-Just Bos (1939–2003), Frans Breteler, Anton Leeuwenberg (1930–2010), Willem JJO de Wilde (1936–2021) and Jan JFE de Wilde, made significant contributions to Annonaceae collections. This period also marks a significant increase in Annonaceae specimen collections in general, which continues until today (Fig. 3B). During the end of last century and the start of the present one, important contributions to the exploration and description of Annonaceae diversity in the country were undertaken by Cameroonian botanists such as Martin Etuge, Jean-Paul Ghogue, Narcisse Kamdem, David Kenfack, Moses Sainge, Bonaventure Sonké and Péguy G. Tchouto Mbatchou, together with foreign botanists such as Stuart Cable, Martin Cheek, Thomas Couvreur, George Gosline, David Harris, and Duncan Thomas. This exploration led to the last major increase in specimen collections from 2010 to 2019 but did not result in an increase in new species documented for the country (Fig. 3B, C).

Collecting intensity across the country is highly heterogeneous, with certain regions densely collected (Bipindi region, Mount Cameroon, Yaoundé area), whereas others have few or no collections (Fig. 1B) . This is the case for example in the southern part of the East Region, in the national Parks of Nki and Boumba Bek where no collections have been made yet for Annonaceae or for the flora in general (e.g. Sosef et al. 2017). Species diversity is mainly concentrated along the Atlantic forest of southern Cameroon (Fig. 2A), a diversity pattern also reflected in the overall flora (Cheek et al. 2001; Sosef et al. 2017) and for endemic or rare species (Onana 2013), including endemics within major families such as Orchidaceae or Rubiaceae (Droissart et al. 2012). Bipindi and the Ngovayang mountain range appear as a hotspot of Annonaceae diversity (Fig. 2A), partially related to the intense collecting of Zenker in the area (see above). The Ngovayang range is an important hotspot of plant diversity, but is currently under mining threat (Gonmadje et al. 2012; Droissart et al. 2019). Another center of diversity is found around the Mount Cameroon region, also a hotspot of diversity in general for the African flora (Cable and Cheek 1998; Onana 2013).

Conservation

Just over a quarter (25.5%, 24/93) of assessed Annonaceae species occurring in Cameroon have been evaluated as threatened at global levels under IUCN criteria (Table 4). This is below the level of threat across the tropical African flora in general (Brummitt et al. 2015; Stévart et al. 2019). Of the 155 Annonaceae taxa included in the study of Onana (2011), just nine were evaluated as threatened (VU or EN). The available assessments to date also do not include potentially threatened species know from very few collections such as the newly described Uvariopsis etugeana (this flora) and Uvariopsis dicaprio (Gosline et al. 2022). Most other species not assessed belong to diverse liana genera (e.g. Artabotrys, Uvaria) which have yet to be properly assessed. The genus Monanthotaxis, based on a preliminary assessment has more than 50% of its species in a threat category. This underscores once again the importance of taking liana species into account when undertaking assessments.

Morphology of Cameroonian Annonaceae

Cameroonian Annonaceae provide an important sample of the morphological variability encountered across the family in general. Below we provide a brief overview of this variability. All these observations concern Cameroonian Annonaceae, unless stated otherwise.

Habit

In Cameroon, Annonaceae can be large emergent trees (e.g. several species of Xylopia more than 30 m in height), understory trees (e.g. Uvariodendron sp. between 3 and 15 m in hight), shrubs (Neostenanthera neurosericea), scrambling shrubs (i.e. lianas not growing along a tree, but mainly growing on the ground producing long bended stems; some species in Uvaria) and lianas (e.g. Artabotrys, Monanthotaxis). No epiphytic species are known in the family. If we just look at the dichotomy between liana and tree habits, there are 62 liana species (38%) versus 99 tree species (62%). Some species are intermediate between a liana and tree habit. This is the case for example of Neostenanthera myristicifolia, Xylopia thomsonii, or Monodora crispata, which can appear scandent, leaning on surrounding vegetation (Couvreur 2009; Fero et al. 2014).

Annonaceae exhibit two growth architecture patterns (Hallé et al. 1978). In the genera occurring in Cameroon, spiral arrangement of branches on the primary axis has been documented in Annickia, Artabotrys, Duguetia, Greenwayodendron, and Xylopia (Johnson 2003) and Polyceratocarpus (Marshall et al. 2016), and distichous arrangement of branches on the primary axis occurs in Annona, Cleistopholis, Hexalobus, Isolona, Monanthotaxis, Monodora, Sphaerocoryne, Toussaintia, Uvaria, and Uvariodendron (Johnson 2003). Where known, these patterns are useful for field identification of sterile plants, including seedlings. The spiral versus distichous patterns do not correlate with habit, inflorescence position, or sympodial versus monopodial growth, but are highly conserved in most major clades of the family (Johnson 2003).

Trunk

Most Annonaceae species have a smooth and cylindrical trunk with no buttresses or stilt roots. The genus Xylopia is an exception with a range of basal structures from small or large buttresses to stilt roots or no structure at all. This provides a useful character for species identification (Johnson and Murray 2018). The color of the trunk is also a good character with some species having a very white bark with patches of darker grey (Anonidium mannii, Cleistopholis glauca, Greenwayodendron suaveolens, Xylopia hypolampra). Some species are characterized by a deeply furrowed trunk, for example Isolona hexaloba, I. zenkeri, and Hexalobus crispiflorus. Another character of Annonaceae is the thick and tough bark which easily peels off in a single strip, a useful character to identify Annonaceae. In the genus Annickia, the inner side of the bark is of a characteristic bright yellow colour (Versteegh and Sosef 2007).

Leaves

Leaves in Annonaceae are alternate, distichous (in a single plane) and lack stipules. The single plane disposition of the leaves confers a characteristic look to Annonaceae in the forest. Moreover, most species have clearly plagiotropic (horizontally spreading) branches (e.g. Greenwayodendron). Leaves are always entire and the margins are never serrate or dentate. Petiole length varies from 1 to 20 mm, the longer petioles being found in species such as Annona senegalensis, Cleistopholis glauca and Uvariodendron calophyllum.

The leaf blade is inserted either on the top or to the side of the petiole (see fig. 2 of Couvreur 2009). When inserted on top of the petiole, the blade appears to “pinch” the petiole. This gives a distinctive appearance to the base of the leaves and can be a useful taxonomic character to identify sterile collections, for example in Isolona (Couvreur 2009). We have added this character in the descriptions although it isn’t always reported in the taxonomic literature.

Within Cameroonian species, leaf size varies more than 20-fold, from 3–4 cm long in species such as Uvaria klaineana or Xylopia pynaertii, to up to more than 60 cm long in species such as Piptostigma submontanum or Uvariodendron fuscum var. giganteum. However, most species have intermediate-sized leaves between 10 and 30 cm long.

Most Annonaceae species have concolorous leaves, being green on both sides of the leaf blade. Some genera and species, however, can be distinguished by having discolorous leaves, with a much lighter whitish green color of the lower side of the leaf blade, e.g. Afroguatteria, Brieya, Cleistopholis, Monanthotaxis, Piptostigma, Polyceratocarpus, Neostenanthera, Sphaerocoryne, Uvaria or some species of Xylopia.

Venation

In most species, the midrib is flat or sunken on the adaxial surface. The genera Isolona and Monodora are unusual in African Annonaceae as they have a raised midrib (Couvreur 2009), and are thus easily distinguished when sterile. The species Polyceratocarpus pellegrinii also has a raised midrib, while the rest of the genus has a flat or sunken one (Le Thomas 1969b).

Secondary venation can provide a useful taxonomic character in Annonaceae. Most species have fewer than 20 pairs of secondary veins. The genus Piptostigma however, is characterized by leaves with a generally high number of parallel secondary veins (Ghogue et al. 2017), with most species having more than 20 pairs. Piptostigma submontanum has the highest number of secondary veins in Cameroonian Annonaceae, varying between 58 and 65 pairs. Tertiary venation is also a useful taxonomic character to identify Annonaceae genera or species and is either parallel (percurrent) or reticulate. The best way to see the tertiary venation is looking at the lower side of the leaves with a hand lens. Percurrent venation is less frequent, but is characteristic of the genera Monanthotaxis, Neostenanthera, Piptostigma and Polyceratocarpus. In addition, species within genera can have percurrent venation, for example in Uvaria (e.g. Uvaria baumannii, U. poggei). In some cases, the tertiary venation is indistinct either because of the presence of a thick layer of pubescence (e.g. Uvaria klaineana) or because the veins are not marked enough. In some cases, the venation is termed intermediate when veins appear both parallel and reticulate, for example in Artabotrys thomsonii, Polyceratocarpus pellegrinii or Uvaria muricata. Finally, the tertiary venation of Toussaintia hallei is unique, being very tightly reticulate.

Inflorescences

The inflorescences of Annonaceae species are termed monotelic, meaning that the apex of the inflorescence ends with a terminal flower (Weberling 1983; Weberling and Hoppe 1996). Lateral branching from a single prophyll leads to partial inflorescences termed “rhipidia” (Weberling and Hoppe 1996). From this basic structure emerges all the variation in inflorescence types found in Annonaceae, of which we will not provide an in depth review here (see Weberling and Hoppe 1996). In Cameroonian Annonaceae, we encounter a large spectrum of inflorescences, ranging from short single-flowered to very long and many times branched structures with numerous flowers (e.g. Piptostigma multinervium). In the descriptions below we do not go into detail about inflorescence structure, except for certain genera (e.g. Monanthotaxis, Piptostigma) where inflorescence structure presents a useful taxonomic character.

An important character concerns the position of the inflorescences which are, in the most fundamental sense, either ‘axillary’ that is originating from an axillary meristem, or ‘terminal’ that is originating from a terminal meristem (Fries 1919; Le Thomas 1969b; Chatrou 1998; Maas et al. 2003). In the former case, the inflorescences appear in the axil of the leaves (or leaf scars when fallen), whereas in the latter they are positioned opposite or sub-opposite the leaves (or leaf scars when fallen), and in some cases they can even become extra-axillary (Maas et al. 2003). Thus, in this treatment, we use the terms ‘axillary’ to refer to axillary inflorescences and ‘leaf-opposed’ or ‘extra-axillary’ for terminal inflorescences. Inflorescences can occur on young foliate branches (recent leaf flush of up to 2 years old) or older branches with or without leaves (ramiflory, meaning here flowers on branches young and old). Finally, cauliflory whereby the flowers (and thus the fruits) originate directly from the trunk resulting from retardation of anthesis (Weberling and Hoppe 1996), is also a common character for Annonaceae. Cauliflory is present in 43 species. In some cases cauliflory is pushed to an extreme with the trunk almost completely covered with flowers, for example in Uvariopsis submontanum (Kenfack et al. 2003) or Piptostigma multinervium (Ghogue et al. 2017).

Flowers

Most species of Annonaceae have a clearly pedicellate flower, with pedicels generally shorter than 10 cm, and in most cases between 0.2 and 2 cm long. Uvariopsis congolana has (female) pedicels up to 45 cm long that grow from the base of the trunk and along the forest floor (flagelliflory, see Schatz and Wendt 2004). Other species of the genus Uvariopsis can also have long pedicels, and in some cases the length varies between male and female flowers. Female flowers generally have longer and more robust pedicels than male flowers (e.g. U. pedunculosa). Monodora myristica also has long pedicels reaching up to 27 cm long.

In most genera, the pedicel bears a lower and upper bract conforming to Fries’s type 2, the most common situation across Annonaceae (Fries 1919). The number of basal bracts may vary from 1 to numerous. The upper bract can be inserted at different levels along the pedicel, and we distinguish 3 possible cases: in the lower half, towards the middle or in the upper half of the pedicel. In most cases the bracts are minute (1–3 mm) and soon falling. However, in some species the upper bracts can be large (e.g. in Anonidium, Letestudoxa, Monodora) or leaf-like (e.g. Isolona campanulata), and thus provide important taxonomic information. In several cases we were not able to observe the bracts and so the information is missing.

Annonaceae flowers are generally bisexual, with stamens and carpels within the same flower. However, some genera are androdioecious (male and bisexual flowers on different individuals, although this state needs to be confirmed with more detailed field observations), dioecious (male and female flowers on different individuals) or monoecious (male and female flowers on the same individual). In Monanthotaxis we can find bisexual and monoecious species. Several Monanthotaxis species with unisexual flowers have female flowers on the trunk while the male flowers are located high in the canopy in axils of the leaves, therefore collections often only contain male or female flowers. Monoecy has not been proven for M. cauliflora or M. pynaertii, but there are collections with both female and male flowers in other species such as M. bidaultii, M. diclina, M. letouzeyi. Uvariopsis is also monoecious, while Anonidium (but see under A. brieyi), Greenwayodendron and Polyceratocarpus are androdioecious (Le Thomas 1969b; Couvreur et al. 2015; Lissambou et al. 2018).

The receptacle or torus which bears the stamens on the basal part and/or the carpels towards the central apical part is quite variable within Annonaceae in general (van Heusden 1992). In Cameroon, most species have a generally flat or slightly concave receptacle (e.g. Artabotrys, Monanthotaxis). However, some genera and species are characterized by a strongly conical or extended receptacle such as in Mischogyne, Uvariopsis, Toussaintia or Monodora myristica (Luke and Deroin 2005; Couvreur 2009; Gosline et al. 2018). In most species of Xylopia a ring or cone formed by the stamen filaments persists in the center of the torus.

The general floral pattern in Annonaceae is actinomorphic, cyclic and trimerous with one whorl of three sepals and two whorls of three petals each (van Heusden 1992). The two whorls of petals are referred to as outer and inner petals in the descriptions. From this general pattern several deviations occur which are useful generic-level characters. In Annickia, the outer petal whorl is absent, and thus the flower only has three inner petals which are opposite the three sepals. In Uvariopsis, most species have only two sepals and a single whorl of four petals, though U. congolana has a single whorl of three petals. Monanthotaxis tripetala, Uvariopsis congolana and Dennettia tripetala have three (or sometimes four) petals (Le Thomas 1969b; Kenfack et al. 2003; Hoekstra et al. 2021). Finally, Toussaintia is unique among Cameroonian Annonaceae in having 9 to 10 petals in 2 or 3 whorls (Le Thomas 1969b; Luke and Deroin 2005).

Sepals are mostly free or are basally fused. Sometimes it can be hard to distinguish between these two states. In Letestudoxa and some species of Uvaria, the sepals are completely fused into a tube or a “cup” and tear open (generally into three parts) during anthesis. In Xylopia the fused sepals often form a cup-shaped calyx. Petals are free in most species, but in the genera Hexalobus, Isolona and Monodora they are basally fused. In this case the petals form either in single whorl (Hexalobus, Isolona) or two differentiated whorls (Monodora). In the former case, the petals are identical in shape and size (referred to as “not differentiated” in the descriptions) and the petals are clearly fused basally; we refer to the non-fused part as “lobes” and fused part as the “tube” (Couvreur 2009; Botermans et al. 2011). In the latter case, the inner and outer petals have different shapes and sizes (referred to as “differentiated” in the descriptions), retaining the common Annonaceae pattern (Couvreur 2009), at least in appearance; in this case, we used the same terminology as for species with free petals, that is referring to inner and outer petals. Finally, several species within Uvariopsis also have basally fused petals (e.g. U. congolana).

Petal shape and size are very variable across Cameroonian species ranging from 1–2 mm long in male flowers of Monanthotaxis cauliflora (female flowers are larger) to 50 mm in Anonidium mannii, to 79 mm in Xylopia mildbraedii,or even up to 100 mm in Monodora myristica, and from circular (several species in Monanthotaxis) to linear (Artabotrys, Xylopia). In some species, the inner petals are rounded and concave at the base, and form a pollination chamber (e.g. Artabotrys, Neostenanthera, Xylopia). Pollination chambers are also possible by connivance of the inner petal margins (but not fused together), for example in some species of Monodora or Uvariodendron.

Stamens

Stamen number varies from six in three species of Monanthotaxis (Hoekstra et al. 2021) to more than 5000 in Uvariodendron calophyllum (Meinke 2008). The positioning of stamens on the receptacle has generally been referred to as spiral (e.g. Couvreur 2009), but a study indicated that the situation is not that simple with stamen insertion tending towards a complex whorled type pattern (Endress and Armstrong 2011). In any case, it is possible to distinguish stamen “row” numbers which can be useful for species identification (Couvreur 2009), and when possible we provided an estimate of the number of these rows. Stamens are always free, except in Monanthotaxis couvreurii where the 13 to 15 stamens are basally fused into a single staminal ring (Hoekstra et al. 2016), and in many species of Xylopia, where the filaments are connate at the base to form a cone surrounding the carpels. The stamens are composed of an anther with two thecae containing the pollen joined by a connective. The thecae are septate (i.e. having with many horizontal septa visible with a hand lens; in opposition to aseptate) in Neostenanthera and Xylopia (a usefull generic-level character, Tsou and Johnson 2003) and aseptate in all other genera. The shape of the connective apex is quite variable among genera (van Heusden 1992). In most species, the apical part of the connective completely covers the top of the stamens and is discoid in shape, forming a flat rounded structure, protecting the stamens. However, the connective can also be tongue-shaped (apically prolonged), absent or reduced showing the thecae (e.g. Mischogyne) (Gosline et al. 2018). The genus Monanthotaxis has a wide range of stamen and connective shapes (Hoekstra et al. 2018). The connective apex can be a useful taxonomic character to distinguish certain closely appearing species (e.g. Uvaria angolensis versus U. versicolor). Staminodes (sterile stamens) occur in the flowers of Monanthotaxis and Xylopia.

Carpels

In Annonaceae, the carpels are generally free, that is apocarpous, within the flower (van Heusden 1992). Only the genera Isolona and Monodora have truly congenetically fused carpels or syncarpy (Endress 1982; Deroin 1985; Couvreur et al. 2008b; Couvreur 2009). Although there are always several fused carpels (versus the hypothesis that there is just a single carpel (Couvreur et al. 2008b)) in those two latter genera, we do not provide a number because that would necessitate anatomical observation (Deroin 1985; Couvreur 2009).

Carpel number varies from one in Sirdavidia to over 250 in Uvariopsis dioica. We provide a count for each species based on available material, but these numbers remain estimates in most cases. Most species have fewer than 20 carpels. Genera with pseudosyncarpous fruits (see below, Annona, Anonidium, Duguetia, Letestudoxa) generally have more than 50 carpels and up to 120. Other genera such as Uvariodendron or Uvariopsis, Monanthotaxis, Neostenanthera and Uvaria also have species which can have more than 50 carpels. Carpels are generally topped by a stigma which can be variable in shape from bilobed to globose or filiform (van Heusden 1992). Stigma morphology is particularly variable in Xylopia (Johnson and Murray 2018).

The ovules are either numerous and lateral in one or two rows (van Heusden 1992), or basal and one or rarely two in number (e. g., Annona, Annickia, Duguetia, Neostenanthera; (Chatrou 1998; Versteegh and Sosef 2007; Fero et al. 2014)). In this treatment we do not provide details about the ovule number and disposition.

Fruits

Most genera have aggregated fruits composed of individual units termed “monocarps” each resulting from the fertilization of a single carpel (van Setten 1990). In the genera Isolona and Monodora, the fruit is syncarpous and forms a single unit, the seeds having no apparent internal order (Couvreur 2009). In a few other genera, the carpels are free in the flower but fuse during fructification, resulting in a single fruiting unit termed a pseudosyncarpous fruit (Chatrou 1998). Fusion between carpels can be complete (e.g. Annona senegalensis, Duguetia barteri) or basal (e.g. Duguetia dilabens). In Cameroon, four genera have this type of pseudosyncarpous fruit: Annona, Anonidium, Duguetia and Letestudoxa.

Monocarps are either stipitate or sessile. When present, the stipes can be up to 5 cm long in certain species of Annickia, Neostenanthera or Uvaria, conferring to the characteristic “star shape” look to Annonaceae fruits. In Annickia, Cleistopholis, and Neostenanthera, the stipe is articulated at the apex. In some species, the stipe is short (less than 5 mm) but still present. A number of genera have sessile (no apparent stipe) or short-stipitate (less than 5 mm) monocarps, for example Mischogyne, Uvariodendron or Uvariopsis. Sessile and stipitate monocarps can occur within the same genus, for example in Neostenanthera or Uvaria. Monocarps of most Cameroonian genera are indehiscent, but in Xylopia the monocarps dehisce longitudinally along an abaxial suture.

Seeds

Annonaceae seeds are quite variable in size, ranging from 3 mm to more than 40 mm long. Generally in Annonaceae, the seeds are characterized by a ruminate endosperm, resulting from the invasion of the intertegument into the endosperm (van Setten 1990). Seeds generally do not have an aril, but it is present in some genera such as Duguetia and in particular Xylopia. Indeed, African Xylopia have five different aril types: absent, bilobed, brush-like, cupular and fimbriate (Stull et al. 2017; Johnson and Murray 2018). In Cameroon, four character states are present (absent, bilobed, brush-like and fimbriate). In addition, many Xylopia species in Cameroon have a thin pigmented sarcotesta covering the hard inner seed coat.

Taxonomic treatment

Annonaceae Juss. Gen. Pl.: 283, 1789 (as “Anoneae”), nom. cons.

Description

Trees, scrambling shrubs or lianas, up to 50 m tall, monoecious, dioecious or putatively androdioecious. Indumentum, when present, of simple, fasciculate, stellate, or scale-like hairs. Leaves alternate, simple, distichous, margins entire, stipules absent. Inflorescences terminal or axillary, ramiflorous in leaf axils, on young or old leafless branches or cauliflorous, single to many-flowered, pedunculate or subsessile, bracts often present. Flowers bisexual or unisexual, actinomorphic, generally trimerous. Sepals in a single whorl, (2)3(4), valvate or imbricate in bud, free or basally to fully connate. Petals 3, 4 or 6, in 1 or 2(3) whorls, generally differentiated into an inner and outer whorl alternating with the sepals, valvate or imbricate in bud, free, basally or fully connate. Stamens 3 to numerous, inserted onto a flat or convex receptacle; anthers generally exceeded by the connective apex, which forms a a protective cover at the top of the stamen; connective apex flat, extended (tongue shaped) or absent; filaments short or absent, free or rarely fused; staminodes absent or present. Carpels 1 to numerous, free or more rarely fused (syncarpous) in flower; stigma capitate, oblong or variously folded; ovules 1 to numerous, uni- or biseriate, basal or lateral. Fruit generally apocarpous, each carpel producing a single monocarp, or more rarely pseudosyncarpous (carpels fusing during fructification) or syncarpous (unilocular fruits resulting from syncarpous flowers), indehiscent or sometimes dehiscent; monocarps 1 to numerous, sessile to long-stipitate, cylindrical, globose, ovoid, ellipsoid, club-shaped or moniliform, 3 to over 40 mm in length, usually large; seeds 1 to numerous per monocarp, uni- or biseriate, or unordered in syncarpous species, sometimes with arilor sarcotesta; endosperm ruminate, hard.

Distribution

Pantropical, from the Pacific and northern Australia to South East Asia (including southern China), India, Madagascar, tropical Africa, temperate eastern North America south to Central America and South America. 113 genera, and around 2550 species.

In Cameroon, 28 genera and 163 species reported to date.

Notes

Several Annonaceae species have been introduced and are commonly cultivated across the country. Monoon longifolium (Sonn.) B.Xue & R.M.K.Saunders (=Polyalthia longifolia (Sonn.) Hook.f. & Thomson) is sold and grown as an ornamental, and planted mainly along roads in major towns and gardens. Cananga odorata (Lam.) Hook.f. & Thomson (ylang ylang) is sold and planted as an ornamental, with its large flowers emitting a strong sweet scent especially at night. Several non-native species of Annona are planted in gardens for their large sweet fruits, especially A. muricata L. Annona glabra L. is naturalized in coastal mangrove regions of West Africa including Cameroon. These non-native species are not treated here.

Key to the genera of Annonaceae in Cameroon

1 Midrib of leaf blade clearly raised above 2
Midrib of leaf blade sunken,impressed, or flat above 4
2 Petals fused at base (even just shortly); fruits in a single unit (syncarpous) 3
Petals free; fruits in several independent monocarps (apocarpous) Polyceratocarpus pellegrinii
3 Corolla lobes similar and equal in length, forming a distinct tube at the base, margins generally flat Isolona
Corolla lobes clearly differentiated into inner and outer petals; the outer ones longer than inner ones, margins generally undulate or crisped Monodora
4 Liana or scrambling shrub 5
Tree or shrub 14
5 Hook-shaped structures (modified inflorescence) present on branches even in juvenile plants Artabotrys
Hook-shaped structures absent 6
6 Indumentum of stellate and/or fasciculate hairs Uvaria (pro parte)
Indumentum (if present) of simple hairs 7
7 Anthers septate (few species) 8
Anthers not septate (most species) 9
8 Petals subequal; stipe shorter than seeded section of monocarp; indehiscent; several seeds per monocarp Xylopia thomsonii
Outer petals longer than inner; stipe at least twice as long as seeded section of monocarp; monocarps indehiscent; seed 1 per monocarp Neostenanthera myristicifolia
9 Leaves bicolored; above green, below glaucous to whitish; monocarps moniliform when more than one seed, ovules uniseriate 10
Leaves green on both sides; monocarps not moniliform, globose to conical, ovules biseriate 12
10 Tertiary venation percurrent when viewed from below, or if venation obscure, then stamens < 35 Monanthotaxis
Tertiary venation reticulate and stamens > 40 11
11 Inflorescences terminal (leaf opposed or extra-axillary) Afroguatteria
Inflorescences axillary Sphaerocoryne
12 Receptacle columnar or elongated; petals 6 to 12 in 2 or 3 whorls Toussaintia
Receptacle convex but not columnar; petals 6 in two whorls 13
13 Sepals entirely fused, enclosing flower in bud, tearing as flower enlarges; fruits pseudosyncarpous Letestudoxa
Sepals free or basally fused, not enclosing flower in bud; fruits apocarpous Uvaria (pro parte)
14 Indumentum of scale-like hairs (easily visible with a hand lens) Meiocarpidium
Indumentum (if present) of stellate, fasciculate or simple hairs 15
15 Indumentum of stellate and/or fasciculate hairs and fruits pseudosyncarpous Duguetia
Indumentum of simple hairs, or glabrous; fruits mostly apocarpous (pseudosyncarpous in Annona and Anonidium) 16
16 Sepals 2; petals 4 Uvariopsis
Sepals 3; petals 3 or 6 17
17 Inner bark/slash yellow; petals 3, opposite the 3 sepals Annickia
Inner bark/slash cream to reddish; petals 6, or if 3 then only 2 sepals present 18
18 Petals fused into a clear tube at the base, plicate (transversely folded) in bud Hexalobus
Petals free, petals not plicate (not folded in bud) 19
19 Outer petals reduced, sepal like, smaller than inner petals 20
Outer petals not reduced, subequal to or larger than inner petals 21
20 Secondary veins 11 to 17 pairs; inflorescence compact, generally up to than 10(–15) mm long Brieya
Secondary veins (15–)22 to 66 pairs; inflorescence compact to lax, but always longer than 16 mm Piptostigma
21 Receptacle cylindrical; anther connective reduced to a tuft of hairs Mischogyne
Receptacle convex to flat; connective well developed, discoid to apiculate 22
22 Tertiary venation percurrent 23
Tertiary venation reticulate 25
23 Leaf apex obtuse, rounded or emarginate (in Cameroonian species); fruits (pseudo)syncarpous Annona
Leaf apex acute, acuminate or caudate; fruits apocarpous 24
24 Outer petals much longer than inner petals; inner petals forming a dome over the receptacle; anthers septate; seed 1 per monocarp Neostenanthera
Petals sub equal or outer slightly longer; inner petals not forming a dome over the receptacle; anthers not septate; seeds > 1 per monocarp Polyceratocarpus (pro parte)
25 Sepals reduplicate-valvate, buds ridged Uvariastrum
Sepals not reduplicate-valvate, buds not ridged 26
26 Petals homogenously red to pink, all reflexed at maturity; anthers bright yellow in vivo at maturity; carpel 1; monocarp 1 Sirdavidia
Petals green, yellow, cream, not reflexed or only curved outward; anthers not bright yellow; carpels > 1; monocarps generally more than one 27
28 Anthers septate; monocarps dehiscent Xylopia
Anthers not septate; monocarps not dehiscent 29
29 Individuals androdioecious or dioecious with separate male, female or bisexual flowers 30
Individuals with bisexual flowers 31
30 Flowering peduncles present, > 50 mm long; stamens more than 30; fruits (pseudo)syncarpous Anonidium
Flowering peduncle absent; stamens less than 30; fruits apocarpous Greenwayodendron
31 Flowering pedicels > 15 mm; sepals free; outer petals up to five times longer than inner petals Cleistopholis
Flowering pedicels < 15 mm; sepals basally fused; petals subequal 32
32 Petioles 2–5 mm long, 1–2 mm wide; petals 3(4), less than 10 mm long, basally fused Dennettia
Petioles > 4 mm long, 3–9 mm wide; petals 6, 10 mm or longer, free Uvariodendron

Synoptic key

Genera in parentheses means some but not all species have the indicated trait.

Liana or scrambling to scandent shrub: Afroguatteria; Artabotrys; Uvaria; (Monodora); Monanthotaxis; (Neostenanthera); Sphaerocoryne; Toussaintia; Letestudoxa; (Xylopia).

Tree: Annickia; Annona; Anonidium; Brieya; Cleistopholis; Duguetia; Greenwayodendron; Hexalobus; Isolona; Meiocarpidium; Mischogyne; Monodora; Neostenanthera; Piptostigma; Polyceratocarpus; Uvariastrum; Uvariodendron; Uvariopsis; Xylopia.

Slash of the bark yellow: Annickia.

Stilt roots or buttresses present: (Xylopia).

Indumentum of stellate hairs: Annickia, Duguetia; Uvaria.

Indumentum of lepidote hairs: Meiocarpidium.

Hook-like structures on branches: Artabotrys.

Leaves discolorous, light green to whitish below: Afroguatteria; Cleistopholis, Monanthotaxis; Piptostigma, Sphaerocoryne; (Uvaria), (Xylopia).

Trunk whitish overall: Cleistopholis; Greenwayodendron.

Leaves with many parallel secondary veins (> 25): (Piptostigma), (Uvaria), (Uvariodendron).

Midrib clearly raised above: Isolona; Monodora; (Polyceratocarpus).

Sepals 2; petals 4: Uvariopsis; (Monanthotaxis).

Sepals reduplicate-valvate (margins folded in bud): Uvariastrum, Toussaintia.

Petals fused into a single whorl with a distinct tube: Hexalobus; Isolona.

Petals 3: Annickia; Dennettia; (Monanthotaxis).

Petals 9 to 10 inserted in 2 to 3 whorls: Toussaintia.

Petals plicate in bud, transversely folded when open: Hexalobus.

Inner petals much longer than outer: Brieya; Piptostigma.

Anthers septate: Neostenanthera; Xylopia.

Staminodes present: (Monanthotaxis); Xylopia.

Androdioecious, dioecious or monoecious: Anonidium; Greenwayodendron; (Monanthotaxis); Polyceratocarpus; Uvariopsis.

Pseudosyncarpous fruits (individual monocarps visible): Annona, Anonidium, Duguetia, Letestudoxa.

Fruits syncarpous (individuals monocarps not visible) with numerous unordered seeds: Isolona; Monodora.

Monocarps moniliform: Monanthotaxis; (Xylopia).

Monocarps dehiscent: Xylopia.

Seeds arillate: (Duguetia); (Xylopia).

Seeds with a sarcotesta: (Xylopia).

Afroguatteria Boutique, Bull. Jard. Bot. État Bruxelles 21: 104, 1951

Thomas L.P. Couvreur

Type species

Afroguatteria bequaertii (De Wild.) Boutique.

Description

Same as species.

A genus of lianas with three species from Central Africa, in the Democratic Republic of the Congo, Cameroon and Angola (Cabinda); one species in Cameroon, endemic.

This genus was phylogenetically validated (Guo et al. 2017b).

Taxonomy

no revision has yet been published, but see Boutique (1951b) and Paiva (1966).

Afroguatteria discostigma (Diels) X.Guo & R.M.K.Saunders, Taxon 66 (1): 13, 2017

Fig. 4; Map 1A

≡ Cleistopholis discostigma Diels, Bot. Jahrb. Syst. 39: 474, 1907; Oxymitra discostigma (Diels) Ghesq. ex Pellegr., Bull. Soc. Bot. France, 66, 1949; Richella discostigma (Diels) R.E.Fr., in Engler & Prantl Nat. Pflanzenfam., ed. 2, 17a (2): 139, 1959; Friesodielsia discostigma (Diels) Steenis, Blumea 12: 359, 1964.

Type

Cameroon. South Region; Bipindi, Zenker G.A. 2980, Apr 1904: holotype: B[B10 0153055]; isotypes: BM[BM001125042]; BR [BR000008800398]; [BR000008800398]; G[G00308361]; GOET[GOET005676]; HBG[HBG-502538]; K[K000198949]; L[L.1754813]; M[M-0107910]; P[P00363341]; S[S03-2239]; WAG[WAG0053550].

Description

Liana, height unknown, d.b.h. unknown. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches pubescent with short sericeous hairs. Leaves: petiole 3–4 mm long, 1–2 mm in diameter, sparsely pubescent to glabrous, grooved, blade inserted on the side of the petiole, 7.5–10 cm long, 4–5 cm wide, elliptic, apex acuminate, acumen ca.1 cm long, base obtuse, subcoriaceous, below sparsely pubescent to glabrous when young, glabrous when old, above glabrous when young and old, discolorous, whitish below (both when fresh and dry); midrib flat or sunken, above glabrous when young and old, below sparsely pubescent when young, glabrous when old; secondary veins 8 to 13 pairs, glabrous above; tertiary venation reticulate. Individuals bisexual; inflorescences cauliflorous or ramiflorous on young foliate branches, leaf-opposed or extra-axillary. Flowers with 9 perianth parts in 3 whorls, 1 per inflorescence; pedicel 18–22 mm long, ca. 1 mm in diameter, pubescent; in fruit 20–40 mm long, 2–3 mm in diameter, pubescent; bracts not seen; sepals 3, valvate, free, 1–2 mm long, 1–2 mm wide, triangular, apex acute, base truncate, pubescent outside, glabrous inside, margins flat; petals free, subequal; outer petals 3, valvate, 5–6 mm long, 3–4 mm wide, ovate, apex acute, base narrowed, margins flat, pubescent outside, pubescent inside; inner petals 3, valvate, 3–3.5 mm long, 2–3 mm wide, elliptic, apex obtuse, base truncate, margins flat, pubescent outside, pubescent inside; number of stamens not counted, number of rows not seen, 2–3 mm long, oblong; anthers not septate; connective discoid, pubescence not seen; staminodes absent; carpels not seen but free. Monocarps stipitate, stipes 5–10 mm long, 1–2 mm in diameter; monocarps 3 to 7, 10–15 mm long, 5–8 mm in diameter, ellipsoid, apex apiculate, pubescent, smooth, not ribbed, color unknown; seed 1, 13–15 mm long, 5–7 mm in diameter, ellipsoid; aril absent.

Distribution

endemic to Cameroon; known from the South Region.

Habitat

A rare species, in primary lowland rain forests. Altitude 100–200(?) m a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

NE (Not Evaluated), but probably CR.

Uses in Cameroon

None recorded.

Notes

Afroguatteria discostigma is only known from four collections by Zenker, all collected close to the type locality in Bipindi (South Region). It remains incompletely known and measurements here are incomplete. The species can be distinguished by its almost glabrous vegetative parts (young foliate branches and underside of young leaves can be pubescent with short hairs), its small leaves that are glaucous below (both when fresh and dry) and branches drying black. The flowers are borne on terminal pedicels that appear leaf-opposed or extra-axillary, but can also be cauliflorous (Zenker 3023), the carpels have a single ovule and thus monocarps are single-seeded like in Afroguatteria bequaertii (De Wild.) Boutique) (Boutique 1951a). The altitude range given here is the one around Bipindi, but could be higher given that the mountain range Ngovayang (up to 1000 m) is very close.

A recent molecular phylogenetic study showed that this species (under the name Friesodielsia discostigma) clustered in the genus Afroguatteria being sister to the Congolese species A. bequaertii (Guo et al. 2017b). It is thus quite different genetically from the the African species of Friesodielsia (now Monanthotaxis) in which it was placed before based on morphology (van Steenis 1964).

Figure 4. 

Afroguatteria discostigma A branch B upper and lower side of leaf, notice glaucous lower side and network like secondary veins C detail of upper lower side of leaf and petiole D inner (left) and outer petals (right), inner view E stamens front and side views F carpels side view and view of ovules G infructescence with moniliform monocarps A–C from Zenker 2980 [S03-2239] reproduced from Swedish Museum of Natural History Department of Botany (S) https://plants.jstor.org/ D–G from Zenker 3023. Drawings by Hélène Lamourdedieu, Publications Scientifiques du Muséum national d’Histoire naturelle, Paris.

Map 1. 

A Afroguatteria discostigma B Annickia affinis C Annickia chlorantha D Annickia letestui E Annickia polycarpa F Annona senegalensis G Annona senegalensis subsp. oulotricha H Anonidium brieyi I Anonidium mannii. White borders represent region limits in Cameroon; green patches represent protected areas (see methods and Suppl. material 1: Fig. S1).

Specimens examined

South Region: Bipindi, 3.05°N, 10.25°E, 01 January 1905, Zenker G.A. 2102a (BM,BR,E,G,K,P); Bipindi, 3.05°N, 10.25°E, 01 January 1904, Zenker G.A. 3023 (BM,G,K,L,P,WAG); Bipindi, 3.08°N, 10.41°E, 01 March 1914, Zenker G.A. 576 (MA).

Annickia Setten & Maas, Taxon 39 (4): 676, 1990

Thomas L.P. Couvreur

= Enantia Oliv. nom. illeg.; J. Linn. Soc., Bot. 9: 174–175, 1867.

Type species

Enantia chlorantha Oliv. (≡ Annickia chlorantha (Oliv.) Setten & Maas).

Description

Trees, up to 30 m tall, d.b.h. up to 50 cm; stilt roots or buttresses absent, slash yellow. Indumentum of simple, stellate and/or fasciculate hairs. Leaves: petiole 2–9 mm long, 1–2 mm in diameter; blade 3.5–29.5 cm long, 1.5–10.5 cm wide, elliptic to obovate, apex acuminate to acute, base narrowly cuneate to shortly attenuate to rounded; midrib sunken or flat; secondary veins 8 to 13 pairs; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old or young foliate branches, leaf opposed or extra axillary. Flowers with 6 perianth parts in 2 whorls, 1 per inflorescence; pedicel 4–19 mm long; in fruit 10–27 mm long; bracts 1 to 2, basal and one upper towards the middle or lower half of pedicel, 2–8 mm long; sepals 3, valvate, free, 5–22 mm long, triangular, apex acute, base truncate; petals free; outer petals absent; inner petals 3, valvate, 12–34 mm long, 5–19 mm wide, ovate, margins inversely Y-shaped ridged, apex acute, base broad and concave; stamens 60 to 200, in 5 to 6 rows, 2–4 mm long, linear; connective tongue shaped or flattened, glabrous; staminodes absent; carpels free, 20 to 70, ovary 2–4 mm long, stigma lobed or cylindrical, pubescent. Monocarps stipitate, stipes 6–59 mm long, 5 to 55 monocarps, 18–35 mm long, 4–14 mm in diameter, ellipsoid to obovoid, apex sometimes mucronate, smooth, glossy; seed 1, 20–30 mm long, ca. 10 mm in diameter, ellipsoid; aril absent.

A genus of eight species mostly distributed across west and central Africa, with one endemic species in Tanzania; four species occur in Cameroon, none endemic.

The genus is easily identifiable when sterile by its yellow slash, and when fertile, by its leaf opposed or extra-axillary (terminal) flowers with 3 sepals and 3 petals, and stipitate monocarps with a single seed.

Taxonomy

Versteegh and Sosef (2007).

Key to the species of Annickia in Cameroon

1 Upper side of midrib pilose 2
Upper side of midrib glabrous, or pubescent just at the basal part, never pilose 3
2 Lower leaf surface with simple, bifid and trifid hairs; petals pubescent at base inside; monocarps with stipes < 20 mm A. chlorantha
Lower leaf surface at least with some stellate or fasciculate hairs; petals glabrous at base inside; monocarps with stipes > 20 mm A. polycarpa
3 Pubescence on lower leaf surface simple, bifid, trifid or stellate, pointing in all directions 4
Pubescence on lower leaf surface simple or bifid, all hairs pointing towards leaf apex A. affinis
4 Petiole and young shoots tomentose A. letestui
Petiole and young shoots sparsely pubescent to pubescent A. chlorantha

Annickia affinis (Exell) Versteegh & Sosef, Syst. & Geogr. Pl. 77(1): 95, 2007

Figs 5, 7; Map 1B

Enantia affinis Exell, J. Bot. 64, Suppl.: 9, 1926.

= Enantia chlorantha (Oliv.) Setten & Maas var. soyauxii Engl. & Diels, Monogr. Afrik. Pflanzen.-Fam. 6: 70 1901. Type. Gabon. Estuaire, Munda, Sibange Farm, Soyaux H. 125, 21 Sep 1880: lectotype, designated by Versteegh and Sosef (2007), p. 95: B n.v.; isolectotypes: K[K001208605]; P[P00267979].

Type

Angola. Cabinda, Munze, ring at Buco Zau, Gossweiler J. 6675, 11 Sep 1916: holotype K[not seen]: isotypes: BM[BM000547034]; COI[COI00004913]; LISC[LISC000073, LISC000072, LISC000075, LISC000074].

Description

Tree, 3–30 m tall, d.b.h. 3–50 cm; stilt roots or buttresses absent, slash yellow. Indumentum of simple, bifid and fasciculate hairs; old leafless branches glabrous, young foliate branches sparsely pubescent. Leaves: petiole 2–8 mm long, 1–2 mm in diameter, sparsely pubescent, grooved, blade inserted on the side of the petiole; blade 3.5–26 cm long, 1.5–9.5 cm wide, elliptic to obovate, apex acuminate to acute, acumen 1 cm long, base narrowly cuneate to shortly attenuate, coriaceous to subcoriaceous, below pubescent when young and old with simple or bifid hairs pointing towards the leaf apex, above sparsely pubescent when young and old, concolorous; midrib sunken or flat, above sparsely pubescent to glabrous when young and old, below pubescent when young and old; secondary veins 8 to 13 pairs, sparsely pubescent below; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old or young foliate branches, leaf opposed or extra axillary. Flowers with 6 perianth parts in 2 whorls, 1 per inflorescence; pedicel 7–14 mm long, 1–2 mm in diameter, pubescent; in fruit 27 mm long, 2–3 mm in diameter, pubescent; bracts 1–2, basal and one upper towards the middle of pedicel, ca. 4 mm long, ca. 2 mm wide; sepals 3, valvate, free, 7 mm long, ca. 4 mm wide, triangular, apex acute, base truncate, green, pubescent outside, glabrous inside, margins flat; petals free; outer petals absent; inner petals 3, valvate, 15–33 mm long, 5–15 mm wide, ovate to inversely Y–shaped ridged, apex acute, base broad and concave, greenish yellow, margins flat, pubescent outside, glabrous inside; stamens 110 to 175, in 5 to 6 rows, 2–4 mm long, linear; connective tongue shaped, glabrous, yellow; staminodes absent; carpels free, 35 to 70, ovary 3–4 mm long, stigma lobed, pubescent. Monocarps stipitate, stipes 10–40 mm long, 1–2 mm in diameter; monocarps 3 to 34, 20–35 mm long, 9–14 mm in diameter, ellipsoid to obovoid, apex sometimes mucronate, sparsely pubescent, smooth, glossy, black when ripe; seed 1, ca. 30 mm long, ca. 10 mm in diameter, ellipsoid; aril absent.

Distribution

From Nigeria (one collection) to the Republic of Congo and the extreme west of the Democratic Republic of Congo; in Cameroon known from the East, South, Littoral, Center and South-West regions.

Habitat

A very common species; in lowland rain forests in primary and secondary habitats. Altitude 50–650 m a.s.l.

Local and common names known in Cameroon

Bololo, Bonuke, Bunuku bolobo (dial. Duala); Bululu, Mfo, Pobalo, Ufol, Moabé (dials. Ewondo, Bulu); M’Fo, Mofo, Mpuley (dial. Mab Kwasio, Foury 113, Service Forestier du Cameroun 84, Bates 1959); N’jie (Dials. Duala, Punu); Ogowa (Punguegaloa, De Wilde 8492); Moabi jaune (French); évué (dial. Bibaya, Baka).

IUCN conservation status

Least Concern (LC) (Cosiaux et al. 2019a).

Uses in Cameroon

medicine : bark as a malaria prophylaxis; construction: house building, furniture; dyes and tannins: as a yellow dye (Versteegh and Sosef 2007).

Notes

Annickia affinis is distinguished by having overall glabrous branches and petioles and the lower side of the leaf blades which is sparsely pubescent with simple or bifid hairs pointing in the same direction. Annickia affinis is morphologically close to A. chlorantha from which it is distinguished by having a glabrous upper midrib surface (versus pilose in A. chlorantha). In addition, A. chlorantha has few simple hairs pointing in different directions combined with smaller bifid or trifid hairs.

Annickia affinis is the most common species of Annickia and is generally found as a young plant in secondary forest, or as an adult in older secondary or primary forests. For a long time (and still now) Annickia affinis was confused with A. chlorantha (or even Enantia chlorantha), but the latter name is attributed to a different and rarer species (Versteegh and Sosef 2007). Thus, most literature refers to the old name A. (Enantia) chlorantha when referring to A. affinis (the common and widespread species). Previous reports of A. chlorantha outside Nigeria and Cameroon (e.g. Gabon) refer to A. affinis.

Selected specimens examined

Central Region: near Ebolbom village 3 km est of Ngoumou 2 km north west of Otélé, 3.59°N, 11.28°E, 02 May 2013, Couvreur T.L.P. 426 (WAG,YA); Ottotomo Forest Reserve 3 km after reserve base near small loggers road, 3.66°N, 11.28°E, 02 May 2013, Couvreur T.L.P. 437 (WAG,YA); Mefou Proposed National Park, 3.62°N, 11.57°E, 15 March 2004, Etuge M. 5139 (K,YA); Mbam Minkom, 3.96°N, 11.36°E, 19 September 2013, Kamdem N. 143 (YA); Nguila 1, 4.77°N, 11.75°E, 30 April 2017, Kamdem N. 521 (YA); Colline entre Tcherikoy et Sokelle II (30 km NW Eséka), 3.78°N, 10.96°E, 14 December 1973, Letouzey R. 12361 (P,YA). East Region: 77 km south of Yokadouma 30 km after Ngato 15 km after river ALPICAM ‘base de vie’ then 40 km on forestry road starting 4 km before Maséa village, 3.15°N, 14.72°E, 05 March 2019, Couvreur T.L.P. 1203 (MPU,WAG,YA); Deng Deng, 5.21°N, 13.44°E, 19 April 2016, Kamdem N. 422 (YA); 16 km E de Dimako, 4.38°N, 13.57°E, 15 December 1965, Leeuwenberg A.J.M. 7355 (BR,K,MO,P,PHA,WAG,YA); 15 km E of Dimako, 4.38°N, 13.57°E, 08 February 1966, Leeuwenberg A.J.M. 7787 (BR,C,K,MO,P,WAG,YA); Route Mintom I (70 km E de Djoum)-Alati (100 km SE de Djoum)-PK 63, 2.83°N, 13.35°E, 01 January 1973, Letouzey R. 11751 (P,YA). Littoral Region: Ebo Wildlife Reserve Djuma permanent camp On Djuma-Djuma trail, 4.33°N, 10.24°E, 14 February 2014, Couvreur T.L.P. 621 (WAG,YA); Mambe Massif above Boga village 100 km along road from Yaoundé to Ed 3.90°N, 10.77°E, 20 June 2014, Couvreur T.L.P. 657 (WAG,YA). South Region: Ebolowa, 2.96°N, 11.28°E, 01 January 1925, Bates G.L. 1959 (BM,BR,MO); on road Lolodorf-Bipindi ca half way near Mbiguiligui village (Mbikiliki), 3.16°N, 10.53°E, 26 February 2018, Couvreur T.L.P. 1153 (P,WAG,YA); 22 km east from Lélé village, 3.26°N, 10.10°E, 07 September 2013, Couvreur T.L.P. 469 (WAG,YA); ca 15 km east from Lélé village, 2.26°N, 13.29°E, 09 September 2013, Couvreur T.L.P. 492 (WAG,YA); Campo Ma’an National Park 11 km on trail from Ebinanemeyong village on road 7 km from Nyabessan to Campo town, 2.47°N, 10.33°E, 11 February 2015, Couvreur T.L.P. 671 (WAG,YA); A 6 km à l’ouest de Masea (village situé à 50 km au SSW de Yokadouma), 3.14°N, 14.86°E, 05 July 1963, Letouzey R. 5412 (P,YA); Campo-Ma’an area road Nko-elon-Mvini Akok Beryat rock, 2.36°N, 10.25°E, 30 June 2001, van Andel T.R. 3784 (KRIBI,WAG,YA); Bipindi, 3.08°N, 10.42°E, 01 January 1909, Zenker G.A. 3839 (BM,BR,K,MO,P). South-West Region: Ekundu Kundu, 5.15°N, 8.883°E, 30 April 1996, Cheek M. 8297 (K,WAG,YA); Mungo river forest reserve North of Kumba-Tombel road entered ca 05 km West of Mungo bridge, 4.73°N, 9.55°E, 24 October 1998, Cheek M. 9354 (YA); Foot of Nyale Rock, 4.98°N, 9.616°E, 17 November 1998, Cheek M. 9654 (K,YA); on trail through palm oil plantation 3 km before lava flow and Seme Beach hotel when coming from Limbe, 4.05°N, 9.076°E, 18 October 2013, Couvreur T.L.P. 519 (WAG,YA); Kupe village to Loum State Forest, 4.73°N, 9.716°E, 30 May 1996, Etuge M. 2049 (K,WAG,YA); Nyale forest and rock, 5°N, 9.633°E, 15 February 1998, Etuge M. 4235 (K,YA); Edensueh forest, 5.25°N, 9.576°E, 30 November 2000, Etuge M. 4850 (K); Kumba-Mbonge road 500 m W of Meme River bridge between Bole and Mabonji, 4.55°N, 9.25°E, 07 July 1986, Thomas D.W. 6327 (MO); Baro village, 5.27°N, 9.21°E, 03 March 1988, Thomas D.W. 7494 (K,MO,P,WAG).

Annickia chlorantha (Oliv.) Setten & Maas, Taxon 39(4): 676, 1990

Fig. 7; Map 1C

Enantia chlorantha Oliv., J. Linn. Soc., Bot. 9: 175, 1867.

Type

Nigeria. Cross River State; Old Calabar, Thomson W.C 130, Dec 1863: holotype: K[K000380204].

Description

Tree, 9–25 m tall, d.b.h. to 5 cm; stilt roots or buttresses absent, slash yellow. Indumentum of simple, bifid trifid, and fasciculate hairs; old leafless branches glabrous, young foliate branches sparsely pubescent to pubescent. Leaves: petiole 2–9 mm long, ca. 2 mm in diameter, pubescent, slightly grooved, blade inserted on top of the petiole; blade 7–28 cm long, 2–9.5 cm wide, elliptic to obovate, apex acuminate, acumen ca. 1 cm long, base narrowly cuneate to shortly attenuate, coriaceous to papyraceous, below densely pubescent when young, sparsely pubescent when old, hairs simple, bifid or trifid hairs pointing in all directions, above glabrous when young and old, concolorous; midrib sunken or flat, above densely pubescent (pilose) to pubescent at least towards base when young, densely pubescent to pubescent at least towards base when old (rarely glabrous), below pubescent when young and old; secondary veins 8 to 12 pairs, glabrous below; tertiary venation intermediate. Individuals bisexual; inflorescences ramiflorous on young foliate branches, leaf opposed or extra axillary. Flowers bisexual with 6 perianth parts in 2 whorls, 1 per inflorescence; pedicel 5–11 mm long, ca. 1 mm in diameter, densely pubescent; in fruit 10–15 mm long, ca. 2 mm in diameter, densely pubescent; bracts 1–2, one basal and one upper towards the middle of pedicel, basal bract 4–8 mm long; sepals 3, valvate, free, 8–12 mm long, 4–6 mm wide, triangular, apex acute, base truncate, green, pubescent outside, glabrous inside, margins flat; petals free; outer petals absent; inner petals 3, valvate, 15–29 mm long, 6–14 mm wide, elliptic to inversely Y–shaped ridged, apex acute, base broad and concave, greenish yellow, margins flat, pubescent outside, pubescent in a small triangle at the base inside; stamens 145 to 160, in 5 to 6 rows, 2 mm long, linear; connective flattened, glabrous, yellow; staminodes absent; carpels free, 20 to 35, ovary ca. 2 mm long, stigma cylindrical, pubescent. Monocarps stipitate, stipes 6–20 mm long, ca. 1 mm in diameter; monocarps 3 to 27, 10–16 mm long, 4–9 mm in diameter, ellipsoid to obovoid, apex mucronate, sparsely pubescent, smooth, glossy, green turning red to black when ripe; seed 1, ca. 20 mm long, ca. 10 mm in diameter, ellipsoid; aril absent.

Distribution

Known from Nigeria (one collection); in Cameroon known from the East, South, Center and South-West regions.

Habitat

Locally common when present but rare overall, in lowland and premontane rain forests, mainly in primary habitats. Altitude 150–850 m a.s.l.

Local and common names known in Cameroon

Otou han (dial. bulu, Bos 6894), Otoungué (dial. Ewondo, Chevalier 33132).

IUCN conservation status

Least Concern (LC) (Cosiaux et al. 2019b)

Uses in Cameroon

medicine : bark as an antisepctic, against fever, malaria prophylaxis; construction: house building, furniture; dyes and tannins: as a yellow dye.

Notes

Annickia chlorantha is distinguished by having sparsely pubescent branches and petioles and the lower side of the leaf blades pubescent with simple, bifid, trifid or fasciculate hairs pointing in all directions. The midrib is generally densely pubescent (pilose) at least towards the base, but some specimens are reported to be glabrous (Versteegh and Sosef 2007). See notes under A. affinis for confusions surrounding this name. Annickia chlorantha also closely resembles A. letestui, but differs by its sparsely pubescent young branches versus tomentose in A. letestui.

Specimens examined

Central Region: Nkolbisson shrubby low forest on summit of Mt Akockdoué Yaoundé, 3.88°N, 11.45°E, 23 May 1970, Bos J.J. 6894 (BR,MO,P,WAG); Mont Mbam Minkon on trail 3 km from Nkol Nyada village, 3.96°N, 11.40°E, 21 March 2013, Couvreur T.L.P. 414 (WAG,YA); Colline Akok Ndoue près Nkolbisson 5 km WSW Yaoundé, 3.88°N, 11.45°E, 23 May 1970, Farron C. 7335 (P,YA); Yaoundé, 3.86°N, 11.51°E, Feburary 1895, Zenker G.A. 726 (P). Littoral Region: Forêt de Ye Youme, 3.48°N, 12.3°E, 01 June 1917, Chevalier A.J.B. 33132 (P). South-West Region: Bambuko FR, 4.43°N, 9.116°E, 16 September 1951, Olorunfemi J. 30760 (K); Korup National Park, 5.28°N, 9.083°E, 03 April 1988, Thomas D.W. 7555 (MO).

Annickia letestui (Le Thomas) Setten & Maas, Taxon 39(4): 676, 1990

Fig. 6; Map 1D

Enantia letestui Le Thomas, Adansonia sér. 2, 2: 306, 1962.

Type

Gabon. Ogooué-Lolo, Ikembélé, Le Testu G.M.P.C. 8432, Oct 1930: lectotype, here designated: P[P00267987]; isolectotypes: BM[BM000547036]; BR[BR0000006418700]; P[P00362651, P02005895, P02005896].

Description

Tree, 2–8 m tall, d.b.h. unknown; stilt roots or buttresses absent, slash yellow. Indumentum of simple, bifid, fasciculate or stellate hairs; old leafless branches glabrous, young foliate branches tomentose. Leaves: petiole 3–8 mm long, 1–2 mm in diameter, tomentose to sparsely pubescent, cylindrical, blade inserted on top of the petiole; blade 10–29.5 cm long, 3.5–10.5 cm wide, elliptic to obovate, apex acuminate to mucronate, acumen 1–2 cm long, base cuneate to rounded to acuminate, subcoriaceous, above glabrous when young and old, below pubescent when young and old, hairs simple, bifid and stellate pointing in all directions, concolorous; midrib sunken or flat, above glabrous when young and old, below pubescent when young and old; secondary veins 9 to 13 pairs, glabrous below; tertiary venation intermediate. Individuals bisexual; inflorescences ramiflorous on young foliate branches, leaf opposed or extra axillary. Flowers with 6 perianth parts in 2 whorls, 1 per inflorescence; pedicel 4–14 mm long, ca. 2 mm in diameter, sparsely pubescent; in fruit ca. 10 mm long, ca. 2 mm in diameter, pubescent; bracts 2, one basal and one upper towards the lower half of pedicel, basal bract 2–4 mm long, 2–3 mm wide; sepals 3, valvate, free, 5–9 mm long, 3–4 mm wide, triangular, apex acute, base truncate, pubescent outside, glabrous inside, margins flat; petals free; outer petals absent; inner petals 3, valvate, 12–26 mm long, 7–12 mm wide, ovate to inversely Y–shaped ridged, apex acute, base broad and concave, yellow–green, margins flat, pubescent outside, pubescent towards margins inside; stamens 60 to 125, in 5 to 6 rows, ca. 2 mm long, linear; connective flattened, glabrous; staminodes absent; carpels free, 20 to 35, ovary ca. 3 mm long, stigma lobed, pubescent. Monocarps stipitate, stipes 8–19 mm long, ca. 1 mm in diameter; monocarps 8 to 20, 19–25 mm long, 10–14 mm in diameter, ellipsoid, apex mucronate, glabrous, smooth, glossy, green turning red to black when ripe; seeds ca. 20 mm long, ca. 10 mm in diameter, ellipsoid; aril absent.

Figure 5. 

Annickia affinis A flowering branch B detail of lower side of leaf blade C flower bud D detail of receptacle with petals removed E inner petals, inner view F stamens, note different shape of connective (discoid to apiculate) G carpel, whole and showing the single basal ovule H floral diagram I fruit. Annickia polycarpa: J details of lower side of leaf blade K flower bud L fruiting branch A–C from Le Testu 1783 D–I from Letouzey 5412 J–L from Chevalier 1611. Drawings by Hélène Lamourdedieu, Publications Scientifiques du Muséum national d’Histoire naturelle, Paris; modified from Le Thomas (1969b; pl. 57, p. 311, pro parte).

Distribution

From Cameroon to Gabon, and one collection in northern Republic of Congo; in Cameroon known from the South region.

Habitat

A rare species; in lowland rain forests, mainly in primary habitats. Altitude 300–700 m a.s.l.

Local and common names known in Cameroon

M’Fo, Mofo, Mpuley (dial. Mab Kwasio, van Andel 4216); N’jie (Dials. Duala, Punu, Bos 4962).

IUCN conservation status

Least Concern (LC) (Cosiaux et al. 2019c).

Uses in Cameroon

None recorded.

Notes

Annickia letestui is characterized by having tomentose young foliate branches and petioles, the lower side of the leaf blades are pubescent with appressed or erect hairs that are simple, bifid, fasciculate or stellate, pointing in all directions. Versteegh and Sosef (2007) note that the indumentum is quite variable within this species, even within individuals, varying from short and appressed to erect and longer hairs.

Vernacular names are likely to apply to other species of the genus.

Specimens examined

South Region: 15 km from Kribi Lolodorf road, 3.00°N, 10.02°E, 01 July 1969, Bos J.J. 4962 (MO,WAG); Mendoum, 2.22°N, 11.23°E, 13 February 1965, Raynal J. 13392 (P); Campo-Ma’an area Bifa, 2.67°N, 10.28°E, 13 October 2001, Tchouto Mbatchou G.P. BIFAX_150 (WAG); Campo-Ma’an area 2.73°N, 9.873°E, 16 August 2001, van Andel T.R. 3882 (WAG); Campo-Ma’an area near Boussebeliga creek bridge, 2.37°N, 9.822°E, 26 October 2001, van Andel T.R. 4216 (WAG).

Figure 6. 

Annickia letestui A flowering branch B detail of lower side of leaf blade C detail of stellate hair D flower bud E inner petal, inside view F stamen G carpel, whole and showing the single basal ovule A–G from Le Testu 8432. Drawings by Hélène Lamourdedieu, Publications Scientifiques du Muséum national d’Histoire naturelle, Paris; modified from Le Thomas (1969b; pl. 56, p. 307, pro parte).

Figure 7. 

Annickia affinis A detail of the yellow bark B lower side of leaf, petiole and branch C upper side of leaf, petiole and branch D flower E detail of receptacle F and G fruits. Annickia chlorantha H lower side of leaf, petiole and branch I upper side of leaf, petiole and branch J flowers, side view, one petal removed showing receptacle K flower, top view showing the three sepals in front of the petals A no voucher B–C Couvreur 1123, Gabon D, E Couvreur 469, Lélé, Cameroon F Couvreur 519, Mt Etinde, Cameroon G Couvreur 591, Gabon. Photos Thomas L.P. Couvreur.

Annickia polycarpa (DC.) Setten & Maas ex I.M. Turner, Phytotaxa 32: 52, 2011

Fig. 5; Map 1E

≡ Unona polycarpa DC., Syst. Nat. 1: 499, 1817; Coelocline polycarpa (DC.) A.DC., Mém. Anon.: 33, 1832; Melodorum polycarpum (DC.) Benth., Trans. Linn. Soc. London 23: 477–478, 1862; Xylopia? polycarpa (DC.) Oliv., Fl. Trop. Afr. 1: 32, 1868.

Type

Sierra Leone. no region; no locality, Afzelius A. s.n., no date: holotype: B[B 10 0068937]; isotype: BM[BM000547035].

Description

Tree, 2–20 m tall, d.b.h. unknown; stilt roots or buttresses absent, slash yellow. Indumentum of simple, bifid, fasciculate or star hairs; old leafless branches glabrous, young foliate branches densely pubescent to tomentose. Leaves: petiole 3–8 mm long, 2 mm in diameter, densely pubescent to tomentose, grooved, blade inserted on the side of the petiole; blade 5–27 cm long, 2–8 cm wide, elliptic to obovate, apex acuminate, acumen 1–2 cm long, base cuneate to acuminate, coriaceous, below pubescent when young and old, hairs mainly bifid or stellate but some simple too, pointing in all directions, above pubescent when young and old, concolorous; midrib sunken or flat, above pubescent towards base when young, pubescent towards base when old, below pubescent when young, sparsely pubescent when old; secondary veins 8 to13 pairs, pubescent below; tertiary venation intermediate. Individuals bisexual; inflorescences ramiflorous on old or young foliate branches, leaf opposed or extra axillary. Flowers with 6 perianth parts in 2 whorls, 1 per inflorescence; pedicel 9–19 mm long, ca. 2 mm in diameter, pubescent; in fruit 20 mm long, 4–5 mm in diameter, pubescent; bracts 2, one basal and one upper towards the middle of pedicel, basal bract 8 mm long, 4 mm wide; sepals 3, valvate, free, 9–22 mm long, 4–5 mm wide, triangular, apex acute, base truncate, pubescent outside, glabrous inside, margins flat; petals free; outer petals absent; inner petals 3, valvate, 23–34 mm long, 8–19 mm wide, elliptic to inversely Y–shaped ridged, apex acute, base broad and concave, claw mm long, yellow, margins wavy, densely pubescent outside, glabrous inside; stamens 90 to 200, in 5 to 6 rows, 3–4 mm long, linear; connective flattened, glabrous; staminodes absent; carpels free, ca. 70, ca. ovary 3 mm long, stigma lobed, sparsely pubescent. Monocarps stipitate, stipes 19–59 mm long, 1–2 mm in diameter, monocarps 5 to 55, 18–23 mm long, 8–12 mm in diameter, obovoid, apex mucronate, sparsely pubescent, smooth, glossy, green turning red to black when ripe; seed 1, ca. 20 mm long, ca. 10 mm in diameter, ellipsoid; aril absent.

Distribution

A mainly West African species, from Sierra Leone to Cameroon; in Cameroon known from the South region.

Habitat

A rare species in Cameroon, in lowland and pre-montane rain forests mainly in primary habitats. Altitude 110–1400 m a.s.l.

Local and common names known in Cameroon

Pola (Mvaï, Fang, Annet 174); African yellow wood, yellow wood (english); Moambe jaune (french).

IUCN conservation status

Least Concern (LC) (Cosiaux et al. 2019d).

Uses in Cameroon

medicine : bark as an antisepctic, against fever, malaria; construction: house building, furniture; dyes and tannins: as a yellow dye.

Notes

Annickia polycarpa is distinguished by the densely pubescent to tomentose upper side of the midrib and the petioles, and generally long stipes.

Specimens examined

South Region: Bipindi, 3.26°N, 10.20°E, 09 June 1928, Annet E. 174 (P).

Annona L. , Sp. Pl. 1: 536, 1753

Thomas L.P. Couvreur

= Guanabanus Mill. Gard. Dict. Abr., ed. 4: 2, 1754.

Type species

Annona muricata L.

Description

Trees, 1–10 m tall, d.b.h. 2–10 cm; stilt roots or buttresses absent. Indumentum of simple hairs. Leaves: petiole 7–20 mm long, 1–3 mm in diameter, blade 6–25 cm long, 4–19 cm wide, broadly obovate or obovate to broadly elliptic to elliptic, apex rounded or obtuse or shortly emarginated, base subcordate to rounded, discolorous, whitish below or concolorous; midrib sunken or flat; secondary veins 7 to 16 pairs; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on young and old leafless branches, leaf opposed. Flowers with 9 perianth parts in 3 whorls, 1 to 2 per inflorescence; flowering peduncle sometimes present, short; pedicel 10–25 mm long; in fruit 15–50 mm long; bracts 2, all basal, 1–5 mm long; sepals 3, valvate, free, 3–4 mm long, triangular to ovate, apex acute, base truncate; petals free; outer petals longer than inner; outer petals 3, valvate, 10–15 mm long, 8–10 mm wide, ovate, apex acute, base truncate; inner petals 3, valvate, 8–10 mm long, 3–4 mm wide, narrowly oblong or narrowly elliptic, apex acute to obtuse, base truncate; stamens numerous (not counted), in 2 to 3 rows, 2–3 mm long, linear; connective discoid, shortly pubescent; staminodes absent; carpels free, numerous (not counted), ovary 1–2 mm long, stigma capitate, glabrous or pubescent. Fruit pseudosyncarpous, 20–50 mm long, 20–50 mm in diameter, obovoid to globose; monocarps sessile, completely fused between them, numerous (not counted); seed 1, 8–10 mm long, 4–5 mm in diameter, flattened ellipsoid, irregular in shape; aril absent.

A mainly South American genus, one of the largest in Annonaceae with about 170 accepted species (Rainer 2001). In Africa, there are between three or four native species, with numerous subspecies and varieties and of which the taxonomy remains complicated (Robyns and Ghesquière 1934; Sillans 1952; Le Thomas 1969c). Annona glabra L. is probably of South American origin (Le Thomas 1969b, 1969c) but is naturalized along the coast of West and Central Africa. In Cameroon it is also found in mangrove areas, but is little collected (e.g. van der Burgt 130 (WAG)) We thus include it in the key, but do not provide a description. In addition, this genus contains the non-native edible species Annona squamosa L., A. muricata L. and A. reticulata L. (from South America), all of which can be found in cultivation (not included in the descriptions) in Cameroon.

Taxonomy

no recent revision, but see Le Thomas (1969c), Le Thomas (1969b).

Key to the species and taxa of Annona in Cameroon

1 Leaves glabrous, elliptic in shape with an acuminate apex, petiole inserted on the side of the petiole A. glabra
Young leaves always pubescent, generally obovate (more rarely elliptic), rounded to emarginated at the apex; petiole inserted on the top of the petiole 2
2 Lower side of leaf blade tomentose with short curly hairs covering the whole blade A. senegalensis subsp. oulotricha
Lower side of leaf blade glabrescent to densely pubescent with non-curly hairs A. senegalensis subsp. senegalensis

Annona senegalensis Pers. ssp. oulotricha Le Thomas, Hallé, Fl. Gabon, vol. 16: 322, 1969

Fig. 8; Map 1G

= Annona arenaria Thonn. var. obtusa Robyns & Ghesq., Bull. Soc. Roy. Bot. Belge 67: 22 (1934). Type. Republic of the Congo. Pool, Brazzaville, Chevalier A.J.B. 27304, Jul 1912; holotype: P[P00363246].

= Annona arenaria auct., non Thonn., Robyns & Ghesq., Bull. Soc. Roy. Bot. Belge 67: 22 (1934); Annona senegalensis Pers. var. arenaria (Thonn.) Sillans, Bull. Mus. Natl. Hist. Nat., sér. 2, 24: 581 (1952). Type. Democratic Republic of the Congo. Kongo-Central, Temvo, Vermoesen F.M.C. 1592, 20 Fev 1919: neotype, designated by Robyns and Ghesquière (1934, p. 25), sheet here designated: BR[BR0000013871604]; isoneotype: BR[BR0000013871611].

Type

Republic of the Congo. Pool; Bord de la M’Boté, Bouquet, A. 513, 12 Sep 1964: holotype: P[P00363247].

Description

Tree to shrub, 1–6(8) m tall, d.b.h. unknown; stilt roots or buttresses absent. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches brown tomentose. Leaves: petiole 7–20 mm long, 2–3 mm in diameter, brown tomentose, grooved, blade inserted on top of the petiole; blade 6–20 cm long, 5–12 cm wide, obovate to elliptic, apex rounded or obtuse or shortly emarginate, base rounded to subcordate, papyraceous to coriaceous, below densely pubescent, curly hairs covering the whole leaf blade when young and old, above sparsely pubescent to glabrous when young, glabrous when old, discolorous, whitish below; midrib impressed, above glabrous when young and old, below densely pubescent when young and old; secondary veins 8 to 15 pairs, glabrous above; tertiary venation percurrent but also appearing reticulate. Individuals bisexual; inflorescences ramiflorous on old or young foliate branches, leaf opposed or extra axillary. Flowers with 9 perianth parts in 3 whorls, 1 to 2 per inflorescence; pedicel 10–25 mm long, 1–2 mm in diameter, brown tomentose; in fruit 15–30 mm long, 3–4 mm in diameter, pubescent; bracts 2, all basal, 2–5 mm long, 2–3 mm wide; sepals 3, valvate, free, 3–4 mm long, 3–4 mm wide, triangular to ovate, apex acute, base truncate, green, densely pubescent outside, glabrous inside, margins flat; petals free, inner smaller than outer; outer petals 3, 10–15 mm long, 8–10 mm wide, ovate, apex acute, base truncate, yellow to green, margins flat, tomentose outside, glabrous inside; inner petals 3, valvate, 8–10 mm long, 3–4 mm wide, narrowly oblong or narrowly elliptic, apex acute, base truncate, yellow-green, margins flat, glabrous outside, glabrous inside; stamens numerous, rows not counted, 2–3 mm long, linear; connective discoid, shortly pubescent; staminodes absent; carpels free, numerous, ovary 1–2 mm long, stigma capitate, pubescent. Fruit pseudosyncarpous, 20–50 mm long, 20–50 mm in diameter, obovoid to globose, yellow orange at maturity; individual monocarps 20 to 30, sessile, completely fused between them; apex shortly pyramidal, brown tomentose, smooth, yellow to orange when ripe; seed 1, 8–10 mm long, 4–5 mm in diameter, flattened ellipsoid; aril absent.

Distribution

A west and central African subspecies distributed from Guinea to Ivory Coast and from Cameroon to the Democratic Republic of the Congo and the Central African Republic; in Cameroon known from Adamaoua, Central, East, North, North-West, South-West and West regions.

Habitat

A common species; in lowland savanna regions towards the north, at higher altitudes towards the south, sometimes the dominant tree species in the savanna, reported to naturally invade certain areas (Le Thomas 1969c). Altitude 200–1300 m a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Least Concern (LC) (Botanic Gardens Conservation International and IUCN SSC Global Tree Specialist Group 2019a).

Uses in Cameroon

None recorded, but probably same as for var. senegalensis.

Notes

Subsp. oulotricha is distinguished by the pubescence of the lower surface of leaf blades, which is tomentose with short curly hairs. Besides that, it is very close morphologically to subsp. senegalensis. The species (A. senegalensis) as a whole is very variable morphologically and widespread across the drier parts of sub-Saharan Africa (west to east), also occurring in northern Madagascar (Le Thomas 1969c). Though we have followed the classification of Le Thomas (1969c), the taxonomic limits in this group would need more in-depth studies.

Cheek et al. (2000, p. 114), in the Check list of plants of Mt Oku, reported the presence of A. chrysophylla Bojer (Brunt 234), but this specimen has now been identified as A. senegalensis subsp. oulotricha. Moreover, the former name is now a synonym of A. senegalensis subsp. senegalensis (Le Thomas 1969c).

Robyns and Ghesquière (1934) chose a neotype for the species A. arenaria (now a synonym of A. senegalensis subspecies senegalensis), thinking that no original material seen by Thonning remained (see under that name for details). However, in doing so, they chose a neotype specimen belonging to A. senegalensis subsp. oulotricha (Le Thomas 1969c). When describing this latter species, Le Thomas chose a different type than the one selected by Robyns and Ghesquière (1934) as not to “bring extra confusion to the situation” (Le Thomas 1969c).

Figure 8. 

Annona senegalensis subsp. senegalensis A flowering branch B detail of pubescence on lower side of leaf blade C leaf D detail of pubescence on lower side of leaf blade E longitudinal section of the flower F stamen G carpel, side view and view of the single basal ovule H seed. Annona senegalensis subsp. oulotricha I leaf J detail of pubescence on lower side of leaf blade K fruit branch showing two pseudosyncarpous fruits. Annona glabra L leaf M section of fruit. Drawings by Hélène Lamourdedieu, Publications Scientifiques du Muséum national d’Histoire naturelle, Paris; modified from Le Thomas (1969b; pl. 56, p. 321).

Specimens examined

Adamaoua Region: Meiganga, 6.52°N, 14.3°E, 06 February 1946, Aubréville A. 729 (P); Tignère, 7.37°N, 12.65°E, 01 March 1939, Jacques-Félix H. 3423 (P); Ngaoundéré, 7.32°N, 13.58°E, 01 June 1939, Jacques-Félix H. 4012 (P); 11 km de Ngaoundéré vers Ngakha, 7.32°N, 13.58°E, 06 March 1958, Letouzey R. 606 (P). Central Region: Mont Ngolep massif Ngoro 38 km N de Bafia, 5.09°N, 11.26°E, 21 April 1975, Ngameni B.K. 51 (P); Mont Ngoro à 58 km SW de Linte, 5.09°N, 11.26°E, 17 April 1982, Nkongmeneck B.A. 256 (P). East Region: Bétaré Oya, 5.5°N, 14.1°E, 02 March 1961, Breteler F.J. 1185 (P); Piste Moyenam Rivière Konbo, 4.58°N, 13.68°E, 29 February 1960, Letouzey R. 3187 (P); Piste Moyenam-rivière Koubou, 4.58°N, 13.68°E, 29 February 1960, Letouzey R. 3191 (P). North Region: Garoua, 9.3°N, 13.4°E, 10 February 1946, Aubréville A. 787 (P); Garoua, 9.3°N, 13.4°E, 11 February 1946, Aubréville A. 804 (P); 17 km N of Banyo along road to Mba, 6.91°N, 11.8°E, 29 February 1972, Leeuwenberg A.J.M. 9440 (WAG). West Region: Dschang, 5.45°N, 9.95°E, 13 April 1966, CNAD 317 (P); Nkounden, 5.7°N, 10.67°E, 01 May 1967, CNAD 808 (P); Bangwa ca. 15 km NW of Baganté, 5.2°N, 10.48°E, 30 April 1964, de Wilde W.J.J.O 2359 (P); Between Bangwa and Bangangté ca 8 km NW of Bangangté, 5.16°N, 10.5°E, 12 May 1964, de Wilde W.J.J.O 2589 (P,WAG); Batchingou, 5.13°N, 10.4°E, 01 January 1939, Jacques-Félix H. 3026 (P); Kontchankap, 5.58°N, 10.80°E, 01 February 1939, Jacques-Félix H. 3033 (P); Foumban, 5.72°N, 10.92°E, 01 February 1939, Jacques-Félix H. 3136 (P).

Annona senegalensis Pers. ssp. senegalensis , Syn. Pl. 2: 95, 1807

Fig. 8; Map 1F

= Annona arenaria Thonn., Beskr. Guin. Pl. 257, 1827. non Robyns & Ghesq., Bull. Soc. Roy. Bot. Belge 67: 22, 1934. Type. Ghana. Thonning s.n.: holotype: P [Herb. Jussieu, number: 10799].

= Annona chrysophylla Bojer, Ann. Sci. Nat., Bot. sér. 2, 20: 53, 1943; Annona senegalensis var. chrysophylla (Boj.) Sillans, Bull. Mus. Natl. Hist. Nat., sér. 2, 24: 581 (1952). Type. Comores. Anjouan [Ndzuwani, Nzwani], Bojer W. s.n., s.d.: holotype: We were not able to locate the type specimen. Verdcourt (1971a) suggests it is possibly in P, but it isn’t amongst the scanned specimens, so likely not in P. No specimens were found in W either.

= Annona senegalensis var. latifolia Oliv., Fl. Trop. Africa: 17, 1868. Type. Uganda. Northern region, Madi, Speke & Grant s.n., s.d.: holotype: We were not able to locate the type specimen, which should be in Kew (Oliver 1868, p. 17, Robyns and Ghesquière 1934).

Annona porpetac Boiv. ex Baill.; Bull. Mens. Soc. Linn. Paris 1. 341, 1882; Annona senegalensis var. porpetac (Boiv. Ex Baill.) Diels, Notizbl. Konigl. Bot. Gart. Berlin 9: 356, 1934. Type. Madagascar. Antsiranana Province, Nossi Be, Bovin M. 2115, 1846: holotype: P[P030360].

Type

Senegal: Roussillon 69, 1798: holotype: P[P00363244].

Description

Tree to shrub, 1–10 m tall, d.b.h. 2–10 cm; stilt roots or buttresses absent. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches brown tomentose. Leaves: petiole 10–20 mm long, 1–2 mm in diameter, brown tomentose, grooved, blade inserted on top of the petiole; blade 7–25 cm long, 4–19 cm wide, broadly obovate to broadly elliptic, apex rounded, base subcordate, subcoriaceous to coriaceous, below densely pubescent with straight hairs to glabrescent when young and old, above sparsely pubescent to glabrous when young, glabrous when old, discolorous, whitish below; midrib impressed, above glabrous when young and old, below densely pubescent when young and old; secondary veins 7 to 16 pairs, glabrous above; tertiary venation percurrent but also appearing reticulate, dense. Individuals bisexual; inflorescences ramiflorous on old or young foliate branches, leaf opposed. Flowers with 9 perianth parts in 3 whorls, 1 to 2 per inflorescence; pedicel 10–20 mm long, 1–2 mm in diameter, brown tomentose; in fruit 25–50 mm long, 3–4 mm in diameter, pubescent; bracts 2, all basal, 1–4 mm long, 2–3 mm wide; sepals 3, valvate, free, 3–4 mm long, 3–4 mm wide, broadly triangular to circular, apex acute, base truncate, green, densely pubescent outside, glabrous inside, margins flat; petals free, outer longer than inner; outer petals 3, 10–15 mm long, 8–9 mm wide, ovate, apex acute, base truncate, yellow to green, margins flat, tomentose outside, glabrous inside; inner petals 3, valvate, 8–10 mm long, 3–4 mm wide, narrowly oblong or narrowly elliptic, apex acute, base truncate, yellow-green, margins flat, glabrous outside, glabrous inside; stamens numerous (not counted), 2–3 mm long, linear; connective discoid, shortly pubescent; staminodes absent; carpels free, numerous (not counted), ovary 1–2 mm long, stigma capitate, glabrous. Fruit pseudosyncarpous; 20–50 mm long, 20–30 mm in diameter, obovoid to globose, yellow orange at maturity, monocarps sessile, numerous, apex flat, glabrous, smooth, yellow to orange when ripe; seed 1, 8–10 mm long, 4–5 mm in diameter, flattened ellipsoid; aril absent.

Distribution

A west, central and east African and northern Malagasy subspecies from Senegal to Mozambique; in Cameroon known from the Adamaoua, Central, East, Far North, North, North-West, South-West and West regions.

Habitat

A common species; in lowland savanna regions towards the north, at higher altitudes towards the southern region, may, sometimes be the dominant tree species across the savanna. Altitude 100–1400 m a.s.l.

Local and common names known in Cameroon

Falŏ (dial. Bamileke (Burkill 1985)); pomme-cannelle du Sénégal (French); African custard-apple; wild custard apple, wild soursop (English).

Uses in Cameroon

food : fruit is eaten, flower for sauces, condiments, spices, flavourings; medicine: root as pain-killer, against diarrh dysentery, cholera, venereal diseases, bark used as vermifuges, diuretics, genital stimulants/depressants, lactation stimulants; construction: house building, furniture; dyes and tannins: astringents, insecticides, arachnicides; products: wood fire; fuel and lighting; social: religion, superstitions, magic.

Notes

Annona senegalensis subsp. senegalensis is distinguished by the pubescence of the lower side of the leaf blade which ranges from densely pubescent (but not tomentose) with short but straight hairs (not curly as in subsp. oulotricha) to glabrescent. See notes under subsp. oulotricha and Le Thomas (1969c) for more details. The fruits are edible.

Le Thomas (1969c p. 2) suggested that there exists a specimen of Thonning sent to Jussieu by Vahl in 1804 and present in P (under catalogue number 10779 from Herb. Jussieu) and that this would be the lectotype. However, we were not able to locate this specimen using the online scanned material.

Specimens examined

Adamaoua Region: Dodéo, 7.48°N, 12.07°E, 01 March 1939, Jacques-Félix H. 3388 (P); Bountoun Mboun mountains ca 40 km N of Ngaoundere, 7.9°N, 13.48°E, 12 April 1977, Nordal I. 929 (P). Central Region: Bibbanga, 3.72°N, 10.3°E, 09 March 1927, Hédin L. 409 (P). East Region: Bertoua-Batouri, 4.58°N, 13.68°E, 01 January 1962, Vroumsia T. 116 (P). Far-North Region: Douzeye (c Bongor), 10.1°N, 15.28°E, 08 January 1968, Achoundong G. 1385 (P); Plaine de Maroua à 5 km au NO de Maroua, 10.6°N, 14.28°E, 18 August 1964, Biholong M. 28 (P); ca 5 km W of Maroua, 10.6°N, 14.28°E, 02 September 1964, de Wilde W.J.J.O 2966 (MO); Bogo (Maroua), 10.7°N, 14.61°E, 01 May 1939, Jacques-Félix H. 3737 (P); Reserve forestière du Mayo Louti (10 km W de Mokolo), 10.7°N, 13.8°E, 10 September 1964, Letouzey R. 6779 (P); Mora, 11.0°N, 14.14°E, 01 January 1945, Vaillant A. 15 (P). North Region: Pitoa, 9.38°N, 13.50°E, 25 March 1974, Achoundong G. 3419 (P); Garoua, 9.3°N, 13.4°E, 04 August 1955, de Wit H.C.D 7182 (WAG); Ecole de faune de Garoua, 9.3°N, 13.4°E, 09 August 2000, Dong E. 391 (P). North-West Region: Piste Munka (=Munkep) 45 km NNW Wum, 6.8°N, 9.97°E, 09 July 1975, Letouzey R. 13988 (MO). South-West Region: Ndop Plain Hillside above Courtar Ndop Amp ref No 28, 6.02°N, 10.49°E, 01 March 1962, Brunt M.A. 51 (K). West Region: Bangwa, 5.2°N, 10.48°E, 12 May 1964, de Wilde W.J.J.O 2389 (P,WAG).

Anonidium Engl. & Diels, Notizbl. Königl. Bot. Gart. Berlin 3: 56, 1900

Thomas L.P. Couvreur

Type species

Anonidium mannii Engl. & Diels.

Description

Trees, 4–30 m tall, d.b.h. up to 80 cm; stilt roots or buttresses absent. Indumentum of simple hairs. Leaves: petiole 3–10 mm long, 2–5 mm in diameter, blade 20–50 cm long, 7–18 cm wide, oblong to obovate, apex rounded or abruptly acuminate, base subcordate forming two small lobes on top of the petiole, concolorous; midrib sunken or flat; secondary veins 10 to 20 pairs; tertiary venation reticulate. Individuals androdioecious or dioecious; inflorescences cauliflorous or ramiflorous on old leafless branches, axillary. Flowers with 9 perianth parts in 3 whorls. 5 to 20 or more per inflorescence; flowering peduncle long, up to 2–4 m, woody, hanging or semi erect; pedicel 10–70 mm long; in fruit 25–100 mm long; bracts 2–4, basal or inserted along the pedicel, 1–5 mm long; sepals 3, valvate, free, 3–4 mm long, triangular to ovate, apex acute, base truncate; petals free; outer petals longer than inner; outer petals 3, valvate, 10–15 mm long, 8–10 mm wide, ovate, apex acute, base truncate; inner petals 3, valvate, 8–10 mm long, 3–4 mm wide, narrowly oblong or narrowly elliptic, apex acute to obtuse, base truncate; stamens 65 to 700, in 2 to 3 rows, 2–3 mm long, linear; connective discoid, shortly pubescent; staminodes absent; carpels free, 180 to 260, ovary 1–2 mm long, stigma capitate, glabrous or pubescent. Fruit pseudosyncarpous, 20–50 mm long, 20–50 mm in diameter, obovoid to globose; monocarps sessile, completely fused, 250 to 500; seed 1, 8–10 mm long, 4–5 mm in diameter, flattened ellipsoid; aril absent.

A genus of trees with four species distributed in Central Africa, one widespread and common across its range (A. mannii) and three others mainly in Gabon (two endemic); in Cameroon two species, none endemic.

Anonidium usambarense R.E.Fr, endemic to Tanzania, is in fact a Polyceratocarpus species (probably Polyceratocarpus scheffleri Engl. & Diels, Couvreur, pers. obs.). Finally, one study (Focho et al. 2010) reports the presence of Anonidium floribundum Pellegr. in the Mount Cameroon area. However, no herbarium collection is available to confirm this and we do not consider it present in Cameroon for now.

Taxonomy

No recent revision has yet been published, but see Le Thomas (1969b) were most species are treated for Gabon.

Key to the species of Anonidium in Cameroon

1 Leaves obovate to oblong-elliptic, 20–45 cm, upper bract inserted at middle of flowering pedicel; individuals male or hermaphrodite (androdioecious); sepals basally fused; outer petals 25–50 mm long, 20–40 mm wide, elliptic to obovate A. mannii
Leaves distinctly oblong, 37–50 cm long; upper bract inserted directly under the calyx, orbicular; individuals female or male (dioecious), sepals free, outer petals 35–60 mm long, 10–18 mm wide; narrowly elliptic to narrowly oblong A. brieyi

Anonidium brieyi De Wild., Repert. Spec. Nov. Regni Veg. 13: 383, 1914

Figs 9, 10; Map 1H

Anonidium mannii var. brieyi (De Wild.) R.E.Fr., Acta Hort. Berg. 10: 80, 1930.

= Anonidium friesianum Exell, J. Bot. 70, Suppl. Polypet.: 211, 1932. Type. Angola. Mayombe, Buco Zau, Gossweiler J. 6690, 16 Sep 1916: lectotype, designated here: LISC[LISC000056]; isolectotypes: COI[COI00004880]; BM[BM000546826, BM000546827]; LISC[LISC000054, LISC000055, LISC000057, LISC000058, LISC000059, LISC000060, LISC000061, LISC000062, LISC000063].

Type

Democratic Republic of the Congo. Bas-Congo; Ganda-Sundi, de Briey J. 86, 1911: lectotype, here designated: BR[BR8822635]; isolectotype: BR[BR8822642].

Description

Tree, 15–25 m tall, d.b.h. up to 35 cm; stilt roots or buttresses absent. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches sparsely pubescent to glabrous. Leaves: petiole 3–10 mm long, 2–5 mm in diameter, sparsely pubescent, soon becoming glabrous, slightly grooved, blade inserted on top of the petiole; blade 37–50 cm long, 10–16 cm wide, oblong, apex rounded to abruptly acuminate, acumen 2–3.5 cm long, base rounded, subcordate, subcoriaceous to coriaceous, below sparsely pubescent when young, glabrous when old, above glabrous when young and old, concolorous; midrib impressed, above glabrous when young and old, below sparsely pubescent when young, glabrous when old; secondary veins 14 to 16 pairs, glabrous above; tertiary venation reticulate. Individuals dioecious; inflorescences cauliflorous or on leafless branches, axillary; peduncle 50–115 mm long, 3–10 mm in diameter, woody, hanging or semi erect from the trunk, glabrous. Flowers with 9 perianth parts in 3 whorls, 1 to 10 per inflorescence, male and female inflorescences similar; pedicel 10–35 mm long, 2–4 mm in diameter, glabrous; bracts, 1 to 2 basal and one upper towards the upper of pedicel, basal bracts 5–10 mm long, 5–10 mm wide; upper bract directly under the calyx, amplexicaul, 12–21 mm long, 10–20 mm wide; sepals 3, valvate, free, 20–40 mm long, 14–18 mm wide, triangular, apex long acuminate, gradually tapering into an acute apex, base truncate, green, densely pubescent outside, glabrous inside, margins flat; petals free, sub equal; outer petals 3, 35–60 mm long, 10–18 mm wide, narrowly elliptic to obovate, apex acute to attenuate, base attenuate, green turning yellow, margins flat, pubescent outside, pubescent inside; inner petals 3, valvate, 30–50 mm long, 9–16 mm wide, narrowly elliptic, apex acute, base truncate, green turning yellow, margins flat, pubescent outside, pubescent inside; stamens in male flowers: 500 to 700 inserted on a conical receptacle, in 14 to 17 rows, 3.5–5 mm long, oblong, connective truncate, sparsely pubescent, green to cream-yellow; carpels in female flower (see notes) 220 to 260, ovary 2–3 mm long, stigma capitate, glabrous; staminodes absent. Whole fruits not seen, label information: ca. 20 cm long, ca. 10 cm in diameter [taken from descriptions on specimens Hallé & Villiers 4505, P02032580], white [taken from Cheek 10240 P00956188]; seed 1, 40–48 mm long, 17–23 mm wide, ellipsoid; aril absent.

Distribution

A central African species, known from Cameroon, Gabon, Republic of the Congo and Angola (Cabinda); in Cameroon known from the Littoral and South-West regions.

Habitat

An uncommon species, in lowland primary or old secondary rain forests. Altitude 100–350 m a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Not evaluated.

Uses in Cameroon

None recorded.

Notes

Anonidium brieyi differs from A. mannii by its usually larger leaves and the narrower inner (10–18 mm wide versus 15–25 mm in A. mannii), and the upper bract inserted just under the calyx (versus near the middle of the pedicel in A. mannii). Three collections seen have strictly female flowers (Couvreur 1132, WAG; Hallé & Villiers 4505, [P02032580]; Sita 712 [MPU411091). The first author’s field observations failed to see any stamens in the thus apparently female flowers (Fig. 10J). A note by Le Testu (Le Testu 1641 [P02032574]) also indicates that the species is dioecious. This suggests that A. brieyi is a strictly dioecious species (male and female flowers on different individuals) rather than androdioecious as in the other species of Anonidium (Le Thomas 1969b). This is the first time this is suggested to occur in this species as only male flowers were described to date. Anonidium letestui Pellegr. (endemic to Gabon) has functionally female flowers, but has a small row of sterile stamens at the base (Le Thomas 1969b), something not observed in the two female specimens examined in A. brieyi (Fig. 10J). Variation of sexual systems within genera (e.g. androdioecious and dioecious species) has been reported in African Annonaceae such as Monanthotaxis (Hoekstra et al. 2021) or Uvariopsis (Couvreur and Luke 2010).

Figure 9. 

Anonidium mannii A leaf B male inflorescence, note upper bract inserted towards lower part of pedicel C receptacle of male flower, all petals removed D stamen E receptacle of bisexual flower, note small row of stamens at base of carpels F longitudinal section of bisexual flower G stamen of bisexual flower, front view H two free carpels, showing basal ovules I fruit, note syncarpous nature, referred to as pseudosycarpous J seed, side view. Anonidium brieyi K flower, note narrow petals A from Le Testu 9169 B–D from Le Testu 9509 E–H from Le Testu 7269 I from Nigerian tree photo J from Le Testu s.n. K from Le Testu 1641. Drawings by Hélène Lamourdedieu, Publications Scientifiques du Muséum national d’Histoire naturelle, Paris; modified from Le Thomas (1969b; pl. 60, p. 331).

Figure 10. 

Anonidium manni A habit, A. manni is the species with white trunk in the center B base of leaf blade, upper side C pseudosyncarpous fruit, note hand for size D Narcisse Kamdem holding an inflorescence E detail of flower, side view F detail of receptacle of bisexual flower, note 2 to 3 rows of stamens at base. Anonidium brieyi G trunk with semi erect inflorescences H leaf, upper side I flower, side view, note narrow petals J detail of receptacle in female flower, note absence of stamens at base of carpels K flower, top view showing insertion of upper bract just belong the calyx A no voucher, Gabon B, C Couvreur 449, Otottomo, Cameroon D, F Couvreur 696, Campo, Cameroon E Couvreur 1207, Maséa, Cameroon G–K Couvreur 1132, Gabon. Photos Thomas L.P. Couvreur.

Le Thomas (1969b) recognized this species as a variety of A. mannii (A. mannii var. brieyi (De Wild.) Fries), however, the morphological differences in addition to its dioecious nature described above warrant it to be retained at the species level for now. Nevertheless, a phylogeographic study of A. mannii based on hundreds of nuclear markers inferred a nested position of A. brieyi (population collected around reference number Couvreur 1132, here identified as A. brieyi) within A. mannii (Helmstetter et al. 2020). This sheds further doubt on the delimitation between these two species and needs further study.

Narrowly elliptic petals are also found in the Gabonese species A. floribundum Pellegr. (not recorded for Cameroon to date). However, this latter species is a small tree up to 4 or 5 m tall, the inflorescences are shorter with fewer flowers, and it is androdioecious (Le Thomas 1969b).

Two herbarium specimens (Cheek 10240, Cameroon; Hallé & Villiers 4505, Gabon) indicate that the collection had fruits, but we were unable to locate them. Cheek 10240 states the fruits are white. Collection Cheek 12040 was identified as A. mannii in the check list of the plants of Mt Kupe (Cheek et al. 2004, p. 236). Four of the type sheets of the name A. friesianum have seeds (Gossweiler 6690, LISC000055, LISC000058, LISC000060, LISC000063). On sheets LISC000055 and LISC000061 there are large narrow structures (18 cm by 3.5 cm) which we cannot identify, either being a dried fruit or part of the bark (?).

The sheet Cheek 10240 from P (P00956188) is a mixed collection. The leaves belong to a species of Uvariopsis (probably connivens), and not A. brieyi. The flowers however are from A. brieyi. The other sheets we have seen appear to have the correct leaves (K, WAG [WAG.1378838])

Finally, for the type of Anonidium friesianum, among the 10 sheets of Gossweiler 6690 available at we did not designate one sheet as lectotype because every sheet has important information (leaves, seeds, leaves) and should be considered as a single collection. Among the 10 sheets of Gossweiler 6690 available at LISC for the type of Anonidium friesianum, we selected a single sheet as the lectotype (LISC000056). Indeed, according to the ICBN, different sheets are considered as a single specimen only if they are cross-referenced (e.g. “Sheet I”, “Sheet II”) which is not the case here. The selected sheet (LISC000056) was the only one that had a leaf and a flower (but broken) thus being the most complete. The other sheets only had either just leaves, or inflorescences or flowers or seeds.

Specimens examined

Littoral Region: Loum Forest Reserve, 4.73°N, 9.731°E, 16 April 2005, Onana J.M. 3101 (K). South-West Region: Banga, 4.55°N, 9.416°E, 01 March 1956, Binuyo A. 35606 (FHO); Southern Bakundu FR, 4.48°N, 9.350°E, 13 March 1948, Brenan J.P.M. 9410 (K,P); Just west of Loum, 4.73°N, 9.729°E, 03 December 1999, Cheek M. 10240 (K,MO,P,WAG,YA); S Bakundu FR, 4.49°N, 9.374°E, 09 April 1951, Olorunfemi J. 30508 (K); 5 km S of Kumba on Buea/Douala Road, 4.65°N, 9.39°E, 21 June 1983, Thomas D.W. 2188 (MO,P,WAG).

Anonidium mannii Engl. & Diels, Notizbl. Königl. Bot. Gart. Berlin 3: 56, 1900

Figs 9, 10; Map 1I

Annona mannii Oliv., Hooker’s Icon. Pl. vol. 11: 7–8, 1867.

= Uvaria crassipetala Engl., Notizbl. Königl. Bot. Gart. Berlin 2: 292, 1899. Type. Cameroon. South-West Region, Station Johann-Albrechtshohe, Staudt A. 813, no date: holotype B destroyed, lectotype, here designated: PH[PH28648].

Type

Nigeria. Cross River State; Old Calabar, Mann G. 2231, 1863: lectotype, sheet here designated: K[K000198881]; isotypes: B[B100153003]; K[K000198882]; P[P00363249].

Description

Tree, 8–30 m tall, d.b.h. 30–80 cm; stilt roots or buttresses absent. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches sparsely pubescent to glabrous. Leaves: petiole 3–7 mm long, 2–3 mm in diameter, sparsely pubescent to glabrous, slightly grooved, blade inserted on top of the petiole; blade 20–45 cm long, 7–18 cm wide, obovate to oblong-elliptic, apex rounded to abruptly acuminate, acumen 2–3 cm long, base rounded to shortly attenuate generally covering part of the petiole, subcoriaceous to coriaceous, below sparsely pubescent when young, glabrous when old, above glabrous when young and old, concolorous; midrib impressed, above glabrous when young and old, below sparsely pubescent when young, glabrous when old; secondary veins 10 to 20 pairs, glabrous above; tertiary venation reticulate, indistinct. Individuals androdioecious; inflorescences cauliflorous or on old leafless branches, axillary; peduncle 0.3–4 m long, up to 2–3 cm in diameter towards the base, woody, hanging, sparsely pubescent to glabrous. Flowers with 9 perianth parts in 3 whorls, 10 to 20 per inflorescence, male and female inflorescences similar; pedicel 10–85 mm long, 2–4 mm in diameter, glabrous; in fruit 25–100 mm long, 10–20 mm in diameter, woody, glabrous; bracts 2–4, several basal and one upper towards the middle of pedicel, basal bracts 7–12 mm long, 7–12 mm wide; upper bract 10–12 mm long, 12–25 mm wide, clasping the pedicel; sepals 3, valvate, basally fused, 15–22 mm long, 17–20 mm wide, triangular to ovate, apex acute, base truncate, green, tomentose outside, glabrous inside, margins flat; petals free, sub equal; outer petals 3, 25–50 mm long, 20–40 mm wide, elliptic to obovate, apex acute or rounded, base truncate, yellow to green, margins flat, pubescent outside, pubescent inside; inner petals 3, valvate, 12–35 mm long, 15–25 mm wide, elliptic, apex rounded, base attenuate to truncate, yellow-green, margins flat, pubescent outside, pubescent inside; stamens in male flowers: numerous on a conical receptacle, 4–4.5 mm long, oblong, connective truncate, sparsely pubescent, green to cream–yellow; stamens in hermaphrodite flowers: 65 to 100, in 3–4 rows, 2–2.5 mm long, oblong; connective truncate, sparsely pubescent, green to cream - yellow; staminodes absent; carpels free, 180–210, ovary 3–4 mm long, stigma capitate, glabrous. Fruit pseudosyncarpous, 250–500 mm long, 100–300 mm in diameter; individual monocarps 150 to 180, sessile, completely fused between them; apex shortly pyramidal, glabrous, smooth, glossy, yellow at maturity with white pulp; seed 1, 30–50 mm long, 17–30 mm in diameter, flattened to oblong; aril absent.

Distribution

A central African species, from southeastern Nigeria to the Republic of Congo, and in the Democratic Republic of the Congo; in Cameroon known from the East, South, Central, Littoral, South-West and West regions.

Habitat

A widespread and very common species across its range; in evergreen or semi-deciduous primary, old or young secondary, lowland or premontane rain forests. Altitude: 0–1600 m a.s.l.

Local and common names known in Cameroon

mbé, nbwé, ombé (dial. Bagali, Baka), ébom, ében, ébon ntangan (dial. Ewondo, Hochuli 4).

IUCN conservation status

Least Concern (LC) (Harvey-Brown 2019a).

Uses in Cameroon

Food : fruit is eaten; medicine: bark used against arthritis, rheumatism, stomach troubles, diarrho dysentery, menstrual cycle, antidotes, paralysis, epilepsy, convulsions, spasms; social: religion, superstitions, magic.

Notes

Anonidium mannii is easily recognizable by its characteristic large leaf blades with a slightly cordate base covering part of the petiole, its long and woody inflorescences hanging from the trunk or old leafless branches and its syncarpous fruits up to 50 cm long and 30 cm large. It is morphologically close to A. brieyi but differs mainly by the wider inner and outer petals, and slightly smaller leaf blades and individuals being androdioecious (see notes under A. brieyi).

Selected specimens examined

Central Region: Eastern sector of M’fou Nat Park Footpath running E of bridge SE of Ndanan 1, 3.61°N, 11.58°E, 22 October 2002, Cheek M. 11248 (K,YA); near Otele, 3.43°N, 11.14°E, 25 February 2007, Couvreur T.L.P. 106 (WAG,YA); Mont Mbam Minkon on trail 3 km from Nkol Nyada village, 3.96°N, 11.40°E, 21 March 2013, Couvreur T.L.P. 415 (WAG,YA); Ottotomo Forest Reserve on top of small hill in front of reserve house, 3.65°N, 11.29°E, 25 June 2013, Couvreur T.L.P. 452 (WAG,YA); on trail to Oveng Lodge hotel near parking just behind the village of Oveng 30 km on road from Mbalmayo to Sangmeli 3.41°N, 11.70°E, 09 February 2014, Couvreur T.L.P. 609 (WAG,YA); Ottotomo Forest reserve 7 km north-west from Ngoumou 30 km south west from Yaoundé, 3.65°N, 11.28°E, 24 February 2016, Couvreur T.L.P. 987 (WAG,YA); SSW of M’Balmayo, 3.52°N, 11.5°E, 27 February 1964, de Wilde W.J.J.O 1968 (B,B,BR,K,MO,P,WAG,YA); Mbam-Minkom Village de Nkolniada, 3.96°N, 11.40°E, 26 July 2012, Droissart V. 1416 (MO); Nanga Eboko, 4.68°N, 12.36°E, 17 February 1927, Hédin L. 36 (P); Mbam Minkom, 3.96°N, 11.36°E, 19 September 2013, Kamdem N. 142 (YA); Nkila, 4.68°N, 12.37°E, 12 March 1959, Letouzey R. 1547 (P,YA); Ekom, 3.85°N, 11.7°E, 16 February 1947, Letouzey R. 194 (P). East Region: Toungrélo, 4.33°N, 13.53°E, 09 January 1962, Breteler F.J. 2454 (K,P,WAG); 81 km south of Yokadouma 30 km after Ngato 15 km after river ALPICAM ‘base de vie’ then 40 km on forestry road starting 4 km before Maséa village, 3.17°N, 14.69°E, 05 March 2019, Couvreur T.L.P. 1207 (MPU,WAG,YA); Somalomo, 3.32°N, 12.71°E, 18 March 2016, Kamdem N. 415 (YA); Lomié, 3.11°N, 13.58°E, 01 December 2016, Kamdem N. 454 (YA). Littoral Region: Nkam, 4.35°N, 10.67°E, 13 June 1927, Hédin L. 1337 (P). South Region: Campo Ma’an National Park 11 km on trail from Ebinanemeyong village on road 7 km from Nyabessan to Campo town, 2.48°N, 10.33°E, 13 February 2015, Couvreur T.L.P. 696 (WAG,YA); 17 km On the newly reconstructed road from Ebolowa to Minkok, 2.75°N, 11.25°E, 29 January 1975, de Wilde J.J.F.E 7930 (BR,K,MO,P,U,WAG,YA); Massif de Ngovayang village de Atog Boga, 3.25°N, 10.49°E, 05 September 2015, Droissart V. 2158 (BRLU); Essam, 4.68°N, 12.37°E, 13 February 1959, Letouzey R. 1276 (P); Essam (Nanga Eboko), 4.68°N, 12.37°E, 14 February 1959, Letouzey R. 1385 (P); Campo-Ma’an area Nsengou, 2.18°N, 10.58°E, 05 February 2001, Tchouto Mbatchou G.P. 3129 (KRIBI,WAG). South-West Region: Colline de Bokwa 42 km SE Mamfe, 5.71°N, 9.643°E, 07 December 1986, Achoundong G. 1325 (YA); Nyasoso, 4.86°N, 9.7°E, 03 June 1996, Cable S. 2801 (K,YA); Nature trail, 4.81°N, 9.683°E, 15 January 1995, Cheek M. 6009 (K,WAG); Kupe Mount, 4.82°N, 9.683°E, 20 November 1995, Cheek M. 7896 (K,WAG,YA); Nyasoso village at base of My Kupe forest reserve along nature trail, 4.82°N, 9.686°E, 04 April 2016, Couvreur T.L.P. 1053b (WAG,YA); Cameroon Mountain, 4.08°N, 9.1°E, 29 December 1983, Thomas D.W. 2850 (MO,WAG). West Region: Près Bandounga à 40 km au NW de Ndikinimeki, 4.98°N, 10.55°E, 12 February 1972, Letouzey R. 11202 (P,YA).

Artabotrys R.Br., Bot. Reg. 5: 423, 1820

Thomas L.P. Couvreur

= Ropalopetalum Griff. Not. Pl. Asiat. 4: 716, 1854.

Description

Lianas, up to 30 m tall, d.b.h. up to 20 cm; stilt roots or buttresses absent. Indumentum of simple hairs or absent. Leaves: petiole 1–15 mm long, 1–2 mm in diameter; blade 7–26 cm long, 2.5–14 cm wide, elliptic to ovate to obovate to oblong, apex acuminate to acute, base decurrent to subcordate, concolorous; midrib sunken or flat; secondary veins 7 to 16 pairs; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old or young foliate branches, leaf opposed or extra axillary. Flowers with 9 perianth parts in 3 whorls, 1 to 90 per inflorescence; pedicel 2–25 mm long; in fruit 2–25 mm long; bracts 2, all basal, minute, soon falling; sepals 3, valvate, free, 1–15 mm long, triangular, apex acute, base truncate; petals free, sub equal; outer petals 3, valvate, 5–35 mm long, 1–14 mm wide, ovate to elliptic to linear to tubular, apex acute to rounded, base broad and concave; inner petals 3, valvate, 5–30 mm long, 1–9 mm wide, ovate to elliptic to linear to tubular, apex acute to rounded, base broad and concave, forming a pollination chamber over the receptacle; stamens 15 to 70, in 2 to 5 rows, 2–3 mm long, linear or cuneiform; connective discoid, glabrous or pubescent; staminodes absent; carpels free, 3 to 32, ovary 1–4 mm long, stigma bilobed or cylindrical, pubescent or glabrous. Monocarps sessile or substipitate, stipe, when present 1–25 mm long, 1 to 20 monocarps, 6–60 mm long, 5–25 mm in diameter, ellipsoid to obovoid, apex rounded to apiculate, smooth or verrucose; seed 1 to 2, 5–25 mm long, 5–15 mm in diameter, ellipsoid or flattened ellipsoid; aril absent.

Type species

Artabotrys odoratissimus R.Br., nom. illegit. (≡ Annona hexapetala L.f., ≡ Artabotrys hexapetalus (L.f.) Bhandari).

A genus of lianas with around 105 species distributed across the paleotropics in South East Asia, Australia, Madagascar and Africa (Chen et al. 2019); eight species occur in Cameroon, one endemic.

Genus easily identifiable by its lianescent habit with the presence of characteristic inflorescences in form of a hook (the peduncle) and flowers that have a broad and concave base.

Taxonomy

To date there are no taxonomic revisions for Artabotrys in Africa, but see Le Thomas (1969b), Boutique (1951b) and Paiva (1966).

Key to the species of Artabotrys in Cameroon

1 Upper side of midrib glabrous, or pubescent just at the basal part, never densely pubescent 2
Upper side of midrib densely pubescent A. thomsonii
2 Young foliate branches and petioles glabrous or sparsely pubescent 3
Young foliate branches and petioles densely pubescent to tomentose 7
3 Petioles 10–15 mm long A. congolensis
Petioles less than 8 mm long 4
4 Leaves 10–20 cm m; sepals 10–15 mm long and 5–8 mm wide, apex of monocarps clearly apiculate, apicule curved A. insignis var. insignis
Leaves smaller than 13 cm; sepals < 5 mm long and < 3 mm wide, apex of monocarps rounded 5
5 Flowering pedicels 10–25 mm long; sepals minute, ca. 1 mm long and ca. 1 mm wide, petals linear, 1–2 mm wide above the broad base, pubescent; monocarps 20–40 mm 10–20 mm in diameter, warty to verrucose, faintly ribbed A. jacquesfelicis
Flowering pedicels 7–10 mm, sepals 3–5 mm long 2–3 mm wide, petals elliptic to ovate, 4–9 mm wide above the broad base, tomentose; monocarps 15–20 mm 7–13 mm in diameter, smooth, not ribbed 6
6 Inflorescence pauciflorous, 1 to 4 flowers A. aurantiacus var. aurantiacus
Inflorescence multiflorous, 6 to 15 flowers A. aurantiacus var. multiflorus
7 Young foliate branches and petioles hirsute with long erect hairs A. rufus
Young foliate branches densely pubescent with appressed or shortly erect hairs 8
8 Lower side of leaf blade densely pubescent brown, base of leaves subcordate with the leaf base inserted on top of petiole, secondary veins 13 to16 pairs, inflorescences multiflorous, > 15 flowers, generally on leafless branches A. dielsiana
Lower side of leaf blade sparsely pubescent to glabrous, base of leaves decurrent to acute with the leaf base inserted on the side of petiole, secondary veins 8 to 12 pairs, inflorescences pauciflorous, < 10 flowers, generally on leafy branches 9
9 Leaves 10–20 cm, leaf base acute, sepals 10–15 mm long and 5–8 m wide, petals 30–35 mm long, 7–12 mm wide, elliptic, not tubular A. insignis var. batesii
Leaves 8–12 cm, leaf base usually decurrent (but can also be acute), sepals 2–3 mm long and 2–3 m wide, petals 5–15 mm long, 1–2 mm wide, linear, tubular in shape A. velutinus

Artabotrys aurantiacus Engl. & Diels, Notizbl. Königl. Bot. Gart. Berlin 2: 300, 1899

Fig. 11; Map 2A

= Artabotrys pynaertii De Wild., Ann. Mus. Congo Belge, Bot. sér. 5, 3(1): 78, 1909. Type. Democratic Republic of the Congo. Equateur, Eala, Pynaert L.A. 606, 15 Oct 1906: lectotype, sheet here designated: BR[BR0000008809971]; isotypes: BR[BR0000008809964, BR0000008809988]; S[S07-13416].

= Artabotrys claessensii De Wild., Bull. Jard. Bot. État Brux. 3: 262, 1911. Type. Democratic Republic of the Congo, Orientale, Yangambi, Claessen, J. 725, Jul 1910: lectotype, sheet here designated: BR[BR0000008809995]; isotype: BR[BR0000008809988].

Type

Cameroon. Central Region; Yaoundé, Zenker G.A. 690, 1896: holotype: B[B 10 0153007]; isotypes: BM[BM000546848]; COI[COI00004927]; P[P00363375, P00363376]; K[K000198859, K000198860].

Description

Liana, height unknown, d.b.h. unknown. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches sparsely pubescent with short appressed hairs. Leaves: petiole 3–5 mm long, 1–2 mm in diameter, pubescent with short appressed hairs to glabrous, grooved, blade inserted on the side of the petiole; blade 7.5–10 cm long, 2.5–6 cm wide, oblong to elliptic, apex acuminate, acumen 0.5–1 cm long, base cuneate to rounded, coriaceous to subcoriaceous, below sparsely pubescent with short appressed hairs to glabrous when young, glabrous when old, above glabrous when young and old, concolorous; midrib sunken or flat, above glabrous when young and old, below pubescent with short appressed hairs when young and old; secondary veins 10 to 12 pairs, glabrous above; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old leafless branches, leaf opposed. Flowers with 9 perianth parts in 3 whorls, 1 to 4 per inflorescence; hook-shaped peduncle 15–20 mm long, sparsely pubescent; pedicel 7–10 mm long, 1–2 mm in diameter, sparsely pubescent; in fruit 7–13 mm long, 2–3 mm in diameter, glabrous; bracts all basal, minute; sepals 3, valvate, free, 3–5 mm long, 2–3 mm wide, triangular, apex acute, base truncate, green, pubescent outside, glabrous inside, margins flat; petals free, sub equal, green turning red-orange; outer petals 3, 15–30 mm long, 4–9 mm wide, narrowly elliptic to narrowly ovate, apex attenuate, base broad and concave, white to light green, margins flat, tomentose outside, tomentose with a glabrous base inside; inner petals 3, valvate, 15–30 mm long, 3–6 mm wide, linear to narrowly elliptic, apex acute, base broad and concave, white to light green, margins flat, tomentose outside, tomentose with a glabrous base inside; stamens 15 to 20, in 2 to 3 rows, 2–3 mm long, cuneiform; connective discoid, glabrous; staminodes absent; carpels free, 8 to 10, ovary ca. 2 mm long, stigma cylindrical, glabrous. Monocarps sessile, 4 to 6, 15–20 mm long, 7–13 mm in diameter, ellipsoid to oblong, apex rounded, glabrous, smooth, red when ripe, not ribbed; seeds 1 to 2 per monocarp, 10–13 mm long, 5–8 mm in diameter, flattened ellipsoid; aril absent.

Distribution

A central African species, from Cameroon to the Republic of Congo and the Democratic Republic of the Congo; in Cameroon known from the Central, East, Littoral, South, South-West and West regions.

Habitat

A common species across its range; in sub montane (sometimes lowland) secondary or primary rain forests. Altitude (100)500–1600 m a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Not evaluated.

Uses in Cameroon

None recorded.

Notes

Artabotrys aurantiacus is distinguished by its sparsely pubescent to glabrous branches and leaf blades (upper and lower sides), with leaves that are relatively small but wide (less than 10 cm and up to 6 cm wide) and oblong to elliptic in shape with a cuneate to rounded base. The flowers have narrowly elliptic petals and the monocarps are smooth, ellipsoid with a rounded apex.

Specimens examined

Central Region: Badjob, 3.68°N, 10.68°E, 21 December 1963, de Wilde W.J.J.O 1602 (BR,MO,P,WAG,YA); Bank Nyong River near the new bridge ca 65 km SSW of Eséka, 3.46°N, 10.5°E, 17 June 1964, de Wilde W.J.J.O 2720 (WAG); Yaoundé, 3.87°N, 11.52°E, 1896, Zenker G.A. 690 (B,K,P). East Region: Ebaka (Bertoua), 4.93°N, 13.32°E, 24 May 1961, Breteler F.J. 1429 (BR,K,M,P,WAG,YA); Ndo Riv (Bertoua), 4.58°N, 13.68°E, 12 December 1961, Breteler F.J. 2210 (BR,K,P,WAG,YA); Doumé Riv (Batouri), 4.23°N, 13.45°E, 15 April 1962, Breteler F.J. 2799 (K,P,WAG); Goyoum, 5.22°N, 13.38°E, 29 January 1961, Breteler F.J. 968 (A,BR,K,M,P,WAG); Nguélémendouka, 4.38°N, 12.92°E, 04 April 1962, de Bruijn J. s.n. (WAG[WAG0175010]); Rives du Dja près Ndongo à 40 km WNW de Moloundou, 2.15°N, 14.86°E, 18 March 1973, Letouzey R. 12141 (P,WAG,YA); Berge arbustive et broussailleuse du fleuve Sanaga au Nord de Goyoum, 5.24°N, 13.36°E, 29 January 1961, Letouzey R. 3309 (P,YA); Rives du Dja entre les rivières Meu et Edjune, 3.41°N, 13.33°E, 12 April 1961, Letouzey R. 3772 (P,YA); Rives de la Kadei entre Mindourou et Dongongo (40 km SSE de Batouri), 4.13°N, 14.60°E, 25 April 1962, Letouzey R. 4859 (P,YA); Betare Oya, 5.59°N, 14.08°E, Tisserant C. 3651 (P). Littoral Region: Manengouba mount base 4 km WNW Of Nkongsamba, 4.96°N, 9.883°E, 09 September 1971, Leeuwenberg A.J.M. 8319 (B,BR,MO,P,U,WAG,YA). South Region: Ebom, 3.1°N, 10.73°E, 13 August 1996, Elad M. 510 (WAG); Nyabesan, 2.4°N, 10.4°E, 05 March 1963, Raynal J. 10240 (P,YA). South-West Region: Likombe, 4.11°N, 9.183°E, 19 February 1995, Cable S. 1309 (K,MO,WAG,YA); Likombe, 4.11°N, 9.183°E, 19 February 1995, Cable S. 1310 (K,WAG,YA); Road to NLO Mt from Kodmin, 5°N, 9.683°E, 23 January 1998, Cheek M. 9063 (K,YA); Nyasoso, 4.81°N, 9.683°E, 08 February 1995, Elad M. 132 (K,YA); Mt Cameroon south slope Transect 8, 4.07°N, 9.015°E, 16 November 1985, Gentry A.H. 52942 (MO,P); Nzee Mbeng trail from Ngomin to Nzee Mbeng, 5.83°N, 9.716°E, 10 February 1998, Gosline W.G. 99 (K,YA); Ndum, 4.83°N, 9.7°E, 31 January 1995, Groves M. 21 (K,MO,WAG,YA); Nyasoso, 4.81°N, 9.683°E, 08 February 1995, Groves M. 77 (K,YA); South slope of mount north of Mt Etinde Forest, 4.08°N, 9.133°E, 20 March 1988, Nemba J. 953 (MO,P). West Region: Bali Ngemba grassland and forest patches northeast of Mantum, 5.82°N, 10.08°E, 12 April 2004, Etuge M. 5373 (K,MO,P,WAG,YA); Dschang, 5.45°N, 9.95°E, 01 May 1960, Jacques-Félix H. 5211 (K,P,WAG); Ngwenfon 35 km NW de Foumban, 5.72°N, 10.92°E, 11 December 1974, Letouzey R. 13495 (P,YA).

Figure 11. 

Artabotrys aurantiacus var. aurantiacus A flowering branch B outer petal, inner view C inner petal, outer and inner views D flowering receptacle with petals removed E stamen F carpel, side view and detail of basal ovules G fruiting branch. Var. multiflorus H flowering branch, note the numerous flowers. Artabotrys insignis var. insignis I flowering branch J outer petal, inner view K inner petal, inner view L flower, whole M stamen N carpel, side view, and detail of ovules O fruiting branch, note long apiculate apex of monocarps A–F from Le Testu 8499 G from Le Testu 4430 H from Le Testu 7116 I–N from Le Testu 8674; 15 from Berteler 2959. Drawings by Hélène Lamourdedieu, Publications Scientifiques du Muséum national d’Histoire naturelle, Paris; modified from Le Thomas (1969b; pl. 26, p. 143).

Artabotrys aurantiacus Engl. & Diels var. multiflorus Pellegr. ex Le Thomas, Adansonia, ser. 2, 5: 447, 1965

Fig. 11; Map 2B

Type

Gabon. Ogooué-Lolo; Lastoursville, Le Testu G.M.P.C. 7116, Mar 1929: lectotype, sheet here designated: P[P02034091]; isotypes: BR[BR0000008820792, BR0000008809940, BR0000008809933]; IFAN[IFAN01625]; LISC[LISC000367]; P[P02034088]; K[K000198858].

Description

Differs from the type variety by the presence of numerous densely packed flowers (6–15 versus 1–4).

Distribution

A central African species, from Cameroon to the Republic of Congo and the Democratic Republic of the Congo, the multiflorus variety is known from Cameroon and Gabon; in Cameroon known from the Central, East, Littoral, South-West and West regions.

Habitat

A rare variety; in sub montane (sometimes lowland) secondary or primary rain forests. Altitude 700–1600 m a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Not evaluated.

Uses in Cameroon

None recorded.

Map 2. 

A Artabotrys aurantiacus B Artabotrys aurantiacus var. multiflorus C Artabotrys congolensis D Artabotrys dielsianus E Artabotrys insignis F Artabotrys insignis var. batesii G Artabotrys jacques-félicis H Artabotrys rufus I Artabotrys thomsonii. White borders represent region limits in Cameroon; green patches represent protected areas (see methods and Suppl. material 1: Fig. S1).

Notes

The variety status is doubtful, but without further investigation, we shall follow Le Thomas (1969b). The main difference between the two varieties is the number of flowers per inflorescence (see above). Le Thomas (1969b) also mentions that var. multiflorus has smaller flowers (smaller than 13 mm) and pedicels of 1 cm long. However, our measurements were not able to confirm these two latter differences.

Specimens examined

Central Region: Près Yaoundé, 3.86°N, 11.45°E, 11 March 1981, Meijer D. 15033 (MO,WAG). West Region: Bali- Ngemba FR, 5.81°N, 10.08°E, 13 April 2002, Onana J.M. 2027 (K,WAG,YA).

Artabotrys congolensis De Wild. & T. Durand, Ann. Mus. Congo Belge, Bot. Sér. 2, 1(1): 2, 1899

Fig. 12; Map 2C

= Artabotrys rhopalocarpus Le Thomas, Adansonia sér. 2, 6: 591, 1966. Type. Central African Republic: Lobaye, Boukoko, Tisserant C. 2242, 25 Sep 1951: lectotype, sheet here designated: P[P00364752]; isotypes: BM[BM000546867]; BR[BR0000008820822]; LISC[LISC000373]; P[P00363392, P00363390]; WAG[WAG0392422].

Type

Democratic Republic of the Congo. Equateur; Lukolela, Dewèvre A.P. 819, 31 Mar 1896: holotype: BR[BR0000008820808]; isotype: B[B 10 0153012].

Description

Liana, height unknown, d.b.h. ca. 8 cm. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches glabrous. Leaves: petiole 10–15 mm long, ca. 2 mm in diameter, glabrous, grooved, blade inserted on the side of the petiole; blade 8–26 cm long, 4–11 cm wide, elliptic to obovate, apex acute to acuminate, acumen 0.5–1 cm long, base acute to decurrent, coriaceous, below glabrous when young and old, above glabrous when young and old, concolorous; midrib impressed, above glabrous when young and old, below glabrous when young and old; secondary veins 8 to 13 pairs, glabrous above; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old leafless branches, leaf opposed. Flowers with 9 perianth parts in 3 whorls, 1 to 3 per inflorescence, hook-shaped peduncle 10–15 mm long; pedicel 10–25 mm long, 2–3 mm in diameter, glabrous; in fruit 12–20 mm long, 2–3 mm in diameter, glabrous; bracts 1 to 2, all basal, basal bracts 2–3 mm long, 1–2 mm wide; sepals 3, valvate, free, 5–8 mm long, 3–7 mm wide, triangular, apex acute, base truncate, pubescent outside, glabrous inside, margins flat; petals free, inner shorter than outer, green turning yellow; outer petals 3, 15–25 mm long, 8–14 mm wide, ovate, apex acute, base broad and concave, margins flat, tomentose outside, tomentose with a glabrous base inside; inner petals 3, valvate, 8–17 mm long, 5–8 mm wide, elliptic to rhombic, apex acute, base broad and concave forming a chamber over the receptacle, margins flat, tomentose outside, tomentose with a glabrous base inside; stamens numerous, number of rows unknown, 2–3 mm long, oblong; connective discoid, glabrous; staminodes absent; carpels free, 15 to 20, ovary 3–4 mm long, stigma tubular, sparsely pubescent. Monocarps stipitate, stipes 1–2 mm long, 1–3 mm in diameter, but gradually widening into seed-bearing part; monocarps 15 to 20, to 60 mm long, ca. 25 mm in diameter, obovoid, apex acute to rounded, glabrous, smooth, glossy, green when ripe; seeds 1 to 2 per monocarp, 19–22 mm long, 10–15 mm in diameter, ellipsoid, laterally flattened; aril absent.

Figure 12. 

Artabotrys congolensis A flowering branch B sepals outer and inner views C outer petals, outer and inner views D side view of outer and inner petals showing the pollination chamber formed by the inner petals E inner petals, outer and inner views F stamen G fruit, notice the stipes gradually widening into the seed bearing part of the monocarps H longitudinal section of a monocarp showing 2 seeds A–F from Tisserant 2242 G, H from Hallé 3451. Drawings by Hélène Lamourdedieu, Publications Scientifiques du Muséum national d’Histoire naturelle, Paris; modified from Le Thomas (1967c).

Distribution

A central African species, from Cameroon to the Republic of Congo and in the Democratic Republic of the Congo; in Cameroon known from the Central, East, Littoral, South and South-West regions.

Habitat

A common species; in lowland or premontane secondary or primary rain forests. Altitude 400–1000 m a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Not evaluated.

Uses in Cameroon

None recorded.

Notes

Artabotrys congolensis is distinguished by its completely glabrous branches, petioles and leaf blades, its outer petals that are broad and the inner petals much narrower and its sessile fruits with a stipes gradually widening into the seed-bearing part of the monocarp.

Le Thomas described Artabotrys rhopalocarpus (Le Thomas 1967c) which was later synonymized with A. congolensis (Bamps and Le Thomas 1989).

Specimens examined

Central Region: near Ebolbom village 4 km est of Ngoumou 3 km north west of Otélé, 3.60°N, 11.28°E, 02 May 2013, Couvreur T.L.P. 431 (MPU,WAG,YA). East Region: Sur axe Lomié-Ngoila-Souanké à 15 km au SSW de Ngola, 2.51°N, 13.86°E, 22 February 1973, Letouzey R. 12016 (P,YA). Littoral Region: Tissongo, 3.57°N, 9.869°E, 09 July 1976, McKey D.B. 111 (K). South Region: Ebolowa-Yaoundé, 3.00°N, 10.92°E, 12 January 1914, Mildbraed G.W.J. 7727 (B). South-West Region: Nyasoso, 4.86°N, 9.7°E, 04 June 1996, Cable S. 2851 (K,YA); Along path from village Mt Etinde summit, 4.05°N, 9.15°E, 02 December 1993, Cable S. 332 (K); Kupe Rock saddle, 4.78°N, 9.716°E, 11 July 1996, Cable S. 3804 (K,YA); Kupe village, 4.78°N, 9.716°E, 17 July 1996, Cable S. 3894 (K,YA); Upper Boando, 4.05°N, 9.153°E, 08 December 1993, Cable S. 475 (K,YA); Mabeta Moliwe reserve 3–5 km east of Limbe, 4.00°N, 9.256°E, 03 July 1992, Cheek M. 3470 (P); Kupe village, 4.77°N, 9.688°E, 29 November 1999, Gosline W.G. 241 (K); Pente E Mont 6 km E Bomana 35 km NW Limbé Alt 950 m, 4.27°N, 9.112°E, 11 December 1984, Villiers J.-F. 2441 (P,YA); Saddle between Mt Etinde and Cameroon, 4.08°N, 9.116°E, 28 October 1992, Wheatley J.I. 644 (K,YA).

Artabotrys dielsianus Le Thomas, Adansonia sér. 2, 9: 442, 1969

Figs 13, 14; Map 2D

Type

Cameroon. South Region; Bipindi, Zenker G.A. 510, 1 Jan 1914: lectotype, sheet here designated: P[P00363381]; isotypes: B[B 10 0153019]; BR[BR0000008820693]; P[P00363377]; U[U 0000237]; WAG[WAG0000084,WAG0000085].

Figure 13. 

Artabotrys dielsiana A branch B detail of the pubescence on the lower side of leaf blade C Inflorescence D flower E sepal, outside side F outer petals inner and outside view G inner petals inner and lateral side views H receptacle with stamens and carpels (stigmas showing) A–H from Zenker 510. Drawings D. Godor de Mauroy, Publications Scientifiques du Muséum national d’Histoire naturelle, Paris; modified from Le Thomas (1969a, pl. 1, p. 441).

Description

Liana, height unknown, d.b.h. unknown. Indumentum of simple hairs; old leafless branches pubescent, young foliate branches tomentose to densely pubescent with long, up to 2 mm, ferruginous hairs. Leaves: petiole 2–3 mm long, 1–2 mm in diameter, densely pubescent, grooved, blade inserted on top of the petiole; blade 15–24 cm long, 6–7 cm wide, elliptic, apex acuminate to acute, acumen 0.5–1 cm long, base subcordate, coriaceous, below densely pubescent when young and old, above sparsely pubescent when young, glabrous when old, concolorous; midrib impressed, above glabrous or sparsely pubescent when young, glabrous when old, below densely pubescent when young and old; secondary veins 13 to 16 pairs, glabrous above; tertiary venation reticulate. Individuals bisexual; inflorescences, ramiflorous on old leafless branches, generally without leaves, leaf opposed. Flowers with 9 perianth parts in 3 whorls, 10 to 15 per inflorescence, hook-shaped peduncle 12–17 mm long; pedicel 3–4 mm long, ca. 1 mm in diameter, densely pubescent; bracts ca. 2, all basal, basal bracts 5 mm long, 4 mm wide; sepals 3, valvate, free, 5–12 mm long, 3–7 mm wide, triangular, apex acute, base truncate, densely pubescent outside, glabrous inside, margins flat; petals free, sub equal; outer petals 3, 20–35 mm long, 6–10 mm wide, elliptic, apex acute, base broad and concave, margins flat, densely pubescent outside, glabrous inside; inner petals 3, valvate, 15–25 mm long, 6–9 mm wide, elliptic, apex acute, base broad and concave, margins flat, densely pubescent outside, pubescent inside; stamens 50 to 70, in 3 to 4 rows, 1–2 mm long, cuneiform; connective discoid, pubescent; staminodes absent; carpels free, 25 to 32, ovary 1–2 mm long, stigma cylindrical, glabrous. Fruits unknown.

Distribution

endemic to Cameroon; known from the South region.

Habitat

Rare species; in primary lowland rain forest. Altitude 0–200 m a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Not evaluated.

Uses in Cameroon

None recorded.

Notes

Artabotrys dielsiana is characterized by its densely pubescent young foliate branches with longish ferruginous hairs, leaf blades with a subcordate leaf base and pubescent below but glabrous above (including the midrib), and tightly packed flowers mainly borne on leafless branches (Le Thomas 1969a). This species has only been collected four times.

Specimens examined

South Region: Lélé, 2.29°N, 13.34°E, 06 September 2013, Couvreur T.L.P. 453 (WAG,YA); Campo-Ma’an area 2.28°N, 9.866°E, 03 October 2001, van Andel T.R. 4128 (KRIBI,U,WAG); Bipindi, 3.08°N, 10.41°E, 01 January 1914, Zenker G.A. 2087 (WAG); Bipindi, 3.08°N, 10.42°E, 01 January 1914, Zenker G.A. 510 (B,P,U,WAG).

Artabotrys insignis Engl. & Diels, Bot. Jahrb. Syst. 34: 483, 1907

Fig. 11; Map 2E

= Artabotrys malchairi De Wild., Etudes Fl. Bangala & Ubangi: 312, 1911. Type. Democratic Republic of the Congo. Equateur, Environ de Likimi, Malchair L. 282, 20 Apr 1910: lectotype, sheet here designated: BR[BR0000014480478]; isotype: BR[BR0000014480461].

= Artabotrys insignis var. latifolius Pellegr., Bull. Soc. Bot. France 94: 256, 1947. Type. Gabon. Ogooué-Lolo, région de Lastoursville, Moughimba, Le Testu G.M.P.C. 8474; 27 Oct 1930: lectotype, here designated: P[P01954179]; isolectotype: BM[BM000546856].

= Artabotrys lucidus A. Chev.; Expl. Bot. Afr. Occ. Franc., 1: 9, 1920, nom. nud.

Type

Cameroon. South Region; Bipindi, Zenker G.A. 2801, 1904: lectotype, sheet here designated: B[B 10 0153021]; isotypes: B[B 10 0153022]; COI[COI00004928]; GOET[GOET005674]; HBG[HBG502547]; K[K000198855]; MO[MO-216862]; P[P00363364]; S[S-G-7465]; WAG[WAG0053175]; WU[WU0025886].

Description

Liana, up to 10 m tall, d.b.h. unknown. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches pubescent with short appressed hairs. Leaves: petiole 2–3 mm long, 1–2 mm in diameter, sparsely pubescent to glabrous, grooved, blade inserted on the side of the petiole; blade 10–20 cm long, 3.5–6 cm wide, ovate to elliptic, apex acuminate to acute, acumen 0.5–1 cm long, base acute, subcoriaceous, below sparsely pubescent when young, glabrous when old, above glabrous when young and old, concolorous; midrib impressed, above sparsely pubescent to glabrous when young, glabrous when old, below sparsely pubescent to pubescent when young, sparsely pubescent when old; secondary veins 9 to 12 pairs, glabrous above; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old leafless branches. Flowers with 9 perianth parts in 3 whorls, leaf opposed, 1 to 3 per inflorescence, hook-shaped peduncle 16–25 mm long; pedicel 2–5 mm long, 1–2 mm in diameter, sparsely pubescent with short appressed hairs; in fruit 2–3 mm long, ca. 2 mm in diameter, glabrous; bracts 2(?), all basal, basal bracts not seen; sepals 3, valvate, free, 10–15 mm long, 5–8 mm wide, triangular, apex acute, base truncate, green turning light reddish, pubescent outside, glabrous inside, margins flat; petals free, sub equal; outer petals 3, 30–35 mm long, 7–12 mm wide, elliptic, apex acute, base attenuate (rounded), green, margins flat but recurved outwards in vivo, pubescent to densely pubescent outside, pubescent to sparsely pubescent inside; inner petals 3, valvate, 15–25 mm long, 2–6 mm wide, elliptic to oblong, apex acute, base broad and concave, margins flat, but recurved outwards in vivo, densely pubescent to pubescent outside, pubescent to sparsely pubescent inside; stamens numerous, number of rows not seen, 2 mm long, cuneiform; connective discoid, glabrous; staminodes absent; carpels free, 12 to 17, ovary 3–4 mm long, stigma cylindrical, pubescent. Monocarps sessile, 7 to 9, 20–25 mm long, 10–12 mm in diameter, ellipsoid, apex long apiculate and slightly curved, glabrous, smooth, not ribbed; red when ripe, seeds 2 per monocarp, 8–11 mm long, 4–6 mm in diameter, flattened ellipsoid; aril absent.

Distribution

A west and central African species, from Sierra Leone to Benin and from Cameroon to the Democratic Republic of the Congo; in Cameroon known from Central, East, South and South-West regions.

Habitat

A fairly common species in Cameroon, in secondary rain forests a long fringes of forests, in swampy regions too. Altitude 100–800 m a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Not evaluated.

Uses in Cameroon

None recorded.

Notes

Artabotrys insignis var. insignis is distinguished by its overall relatively glabrous branches and petioles, long (> 10 cm) elliptic leaves with an acute leaf base (more rarely rounded), long (10–15 mm) triangular sepals, long and wide petals, and glabrous smooth fruits with a distinctive long curved apicule.

Specimens examined

Central Region: Route Ndanan I-Ndangan I, 3.62°N, 11.58°E, 10 March 2004, Cheek M. 11641 (K,YA); Yangafok II 25 km ENE de Bafia, 4.93°N, 11.37°E, 26 November 1969, Letouzey R. 9607 (P,YA). East Region: 82 km south of Yokadouma 30 km after Ngato 15 km after river ALPICAM ‘base de vie’ then 40 km on forestry road starting 4 km before Maséa village, 3.15°N, 14.73°E, 06 March 2019, Couvreur T.L.P. 1214 (MPU,WAG,YA). South Region: Campo Ma’an National Park 11 km on trail from Ebinanemeyong village on road 7 km from Nyabessan to Campo town, 2.46°N, 10.35°E, 14 February 2015, Couvreur T.L.P. 710 (WAG,YA); Ebom, 3.1°N, 10.73°E, 25 February 1997, Elad M. 580 (KRIBI,WAG); Ebom, 3.1°N, 10.71°E, 26 February 1997, Parren M.P.E. 4 (KRIBI,WAG); Bipindi, 3.08°N, 10.41°E, 01 January 1904, Zenker G.A. 2801 (B,BR,K,L,P,WAG); Bipindi, 3.08°N, 10.42°E, 01 January 1907, Zenker G.A. 3320 (P). South-West Region: Mount Cameroon National Park on the Bomona trail behind Bomona village 10 km NW from Idenau, 4.29°N, 9.096°E, 03 April 2016, Couvreur T.L.P. 1044 (MPU,WAG,YA); Korup National Park, 5.28°N, 9.083°E, 03 April 1988, Thomas D.W. 7578 (MO,P).

Artabotrys insignis var. batesii Le Thomas Adansonia, ser. 2, 5: 448, 1965

Fig. 14; Map 2F

Type

Cameroon. East Region; Bitya, near Dja river, Bates G.L. 1792, Sep 1922: holotype: P[00363370].

Description

Differs from the type variety by its densely brown tomentose and shortly hirsute branches and petioles, pubescent lower side of leaf blades and tomentose petals.

Distribution

A west and central African species, from Sierra Leone to Benin and from Cameroon to the Democratic Republic of the Congo; in Cameroon known from Central, East, South and South-West regions.

Habitat

A fairly common species in Cameroon, in secondary rain forests a long fringes of forests, in swampy regions too. Altitude 100–800 m a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Not evaluated.

Uses in Cameroon

None recorded.

Notes

Differences between var. insignis and var. batesii are quite small, and are mainly related to the pubescence of the branches, lower side of the leaves and petals (Le Thomas 1965a). There is one more recognized variety within insignis: var. concolor (Pellegr.) Le Thomas which differs by having shiny leaves on both sides and longer sepals. We have not seen this variety in Cameroon, but it is present in Gabon (Le Thomas 1965a, 1969b).

Figure 14. 

Artabotrys dielsiana A branch B base of leaf blade; upper side C base of leaf blade; lower side D detail of hooked shaped inflorescence (sterile). Artabotrys insignis var. batesii E branch F base of leaf blade; lower side, note tomentose branches G base of leaf blade; upper side, note tomentose branches H flower, side view I flower, top view J flower, bottom view A–D Couvreur 453, Lélé, Cameroon E–J Couvreur 1044, Mt Cameroon, Cameroon. Photos Thomas L.P. Couvreur.

Specimens examined

East Region: Village Djang 40 km west of Bertoua, 4.58°N, 13.35°E, 15 May 1962, Breteler F.J. 2956 (P,WAG). South Region: Bitye near R Ja, 3.02°N, 12.37°E, 01 September 1922, Bates G.L. 1792 (P); Rive du Ntem à Ebianemeyong 60 km east de Campo, 2.42°N, 10.33°E, 12 April 1970, Letouzey R. 10370 (P,WAG,YA).

Artabotrys jacquesfelicis Pellegr., Bull. Soc. Bot. Fr. 97: 15, 1950

Fig. 15; Map 2G

= Artabotrys robustus Louis ex Boutique Bull. Jard. Bot. Etat Brux. 21: 107, 1950. Type. Democratic Republic of the Congo. Orientale, Yangambi, Louis J.L.P. 6077, 16 Sep 1937: lectotype, sheet here designated: BR[BR0000008820686]; isotypes: BR[BR000000882072]; K[K000795930]; NY[NY00025831]; P[P00363357].

Type

Cameroon. Central Region; Nkidi forest, Jacques-Félix H. 2490, Nov 1938: lectotype, sheet here designated: P[P00363361]; isotypes: K; P[P00363359, P00363362].

Description

Liana, height unknown, d.b.h. unknown. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches glabrous. Leaves: petiole 4–7 mm long, ca. 1 mm in diameter, glabrous, grooved, blade inserted on the side of the petiole; blade 8–13 cm long, 3–14 cm wide, oblong to elliptic, apex acute, acumen ca. 0.5 cm long, base decurrent to acute, coriaceous, below glabrous when young and old, above glabrous when young and old, shiny when dried, concolorous; midrib impressed, above glabrous when young and old, below glabrous when young and old; secondary veins 9 to 12 pairs, glabrous above; tertiary venation reticulate. Flowers bisexual with 9 perianth parts in 3 whorls. Individuals bisexual; inflorescences ramiflorous on old leafless branches, leaf opposed. Flowers with 9 perianth parts in 3 whorls, 3 to 6 per inflorescence, hook-shaped peduncle 15–20 mm long; pedicel 10–25 mm long, ca. 1 mm in diameter, glabrous; in fruit 20–30 mm long, 1–2 mm in diameter, glabrous; bracts 1 to 2, all basal, basal bracts ca. 1 mm long, ca. 1 mm wide; sepals 3, valvate, free, 1–2 mm long, ca. 1 mm wide, triangular, apex acute, base truncate, glabrous outside, glabrous inside, margins flat; petals free, sub equal; outer petals 3, 20–35 mm long, 1–2 mm wide, linear to narrowly ovate, apex rounded, base broad and concave, margins flat, pubescent outside, glabrous inside; inner petals 3, valvate, 15–25 mm long, 1–3 mm wide, linear, apex rounded, base broad and concave, margins flat, densely pubescent outside, glabrous inside; stamens 50 to 70, in 3 to 4 rows, 2–3 mm long, oblong; connective discoid, pubescent; staminodes absent; carpels free, 3 to 4, ovary 3–4 mm long, stigma cylindrical, glabrous. Monocarps stipitate, stipes 5–10 mm, ca. 6 mm in diameter, 1 to 4 monocarps, 20–40 mm long, 10–20 mm in diameter, ellipsoid, apex rounded, glabrous, warty to verrucose, faintly ribbed, color when ripe unknown; seeds 1 to 2 per monocarp, 20–25 mm long, 10–15 mm in diameter, flattened ellipsoid; aril absent.

Distribution

A central African species, only known from Cameroon and the Democratic Republic of the Congo; in Cameroon known from the Central and South regions.

Figure 15. 

Artabotrys jacquesfelicis A flowering branch B outer petal, inner view C inter petal, inner view D floral receptacle, petals removed E stamens, front and back view F carpel with detail on ovules G fruiting branch H seed, section latitudinal section I seed, longitudinal section. Artabotrys velutinus J flowering branch K flower receptacle, outer petals removed L outer petal, inner view M inner petal, inner view N flowering receptical, petals removed O stamen P carpel, side view, detail of ovules A–F from Jacques Felix 2490 G–I from Tisserant 2405 J–P from Zenker 1222. Drawings by Hélène Lamourdedieu, Publications Scientifiques du Muséum national d’Histoire naturelle, Paris.

Habitat

A rare species across its range, in primary lowland rain forests. Altitude 500–600 m a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Not evaluated.

Uses in Cameroon

None recorded.

Notes

Artabotrys jacquesfelicis is distinguished by its entirely glabrous branches, petioles and leaves that are shiny above in herbarium material, narrowly ellipsoid flower buds, petals with a large concave base abruptly narrowing into an upper linear section, and ellipsoid monocarps with a warty to verrucose surface. In Cameroon, this species is only known from three old collections.

Specimens examined

South Region: River Ja Bitya, 3.02°N, 12.37°E, 01 January 1922, Bates G.L. 1699 (K); Bipindi, 3.08°N, 10.42°E, 01 January 1909, Zenker G.A. 3834 (L,P).

Artabotrys rufus De Wild., Bull. Jard. Bot. État Bruxelles 4: 386, 1914

Figs 16, 17; Map 2H

= Artabotrys boonei De Wild., Repert. Spec. Nov. Regni Veg. 13: 383, 1914. Syn. nov. Type. Democratic Republic of the Congo. Orientale, Nala, Boone A. 80, 1911: lectotype, sheet here designated: BR[BR0000008820365]; isotype: BR[BR0000008820372].

= Artabotrys dahomensis Engl. & Diels, Notizbl. Königl. Bot. Gart. Berlin 2: 299, 1899. Syn. nov. Type. Benin: Dahome, Newton s.n., 1886: holotype: B[B 10 0153018].

= Artabotrys setulosus Mildbr. & Diels, Bot. Jahrb. Syst. 53. 447, 1915. Type. Cameroon. East Region, Mulundou, Mildbraed G.W.J. 4999, 26 Jan 1911: lectotype, here designated: HBG[HBG502545].

Type

Democratic Republic of the Congo. Equateur; Likimi, Malchair L. 274, 20 Avr 1910: holotype: BR[BR0000008820297]

Description

Liana, to 20 m tall, d.b.h. 3–5 cm. Indumentum of simple hairs; old leafless branches sparsely pubescent, young foliate branches hirsute, with erect hairs. Leaves: petiole 2–4 mm long, 1–2 mm in diameter, hirsute, slightly grooved, blade inserted on top of the petiole; blade 8–14 cm long, 3.5–5.5 cm wide, oblong to obovate, apex acuminate, acumen 0.5–1 cm long, base rounded to subcordate or obtuse, papyraceous, below pubescent when young and old with long appressed hairs, above glabrous when young and old, concolorous; midrib impressed, above glabrous when young and old, below pubescent when young and old; secondary veins 9 to 12 pairs, glabrous above; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old leafless branches, leaf opposed. Flowers with 9 perianth parts in 3 whorls, 1 to 3 per inflorescence, hook-shaped peduncle 4–7 mm long; pedicel 3–5 mm long, ca. 1 mm in diameter, pubescent to sparsely hirsute; in fruit 3–15 mm long, ca. 2 mm in diameter, pubescent; bracts caduceus, not seen; sepals 3, valvate, free, 5–7 mm long, 2–4 mm wide, triangular, apex acute, base truncate, green, hirsute outside, glabrous inside, margins flat; petals free, sub equal, green turning yellow; outer petals 3, 10–20 mm long, 3–4 mm wide, very narrowly elliptic to linear, apex acute, base rounded to broad and concave, green turning bright yellow, margins flat, recurved inwards in vivo, densely appressed-pubescent outside, appressed-pubescent to glabrous inside; inner petals 3, valvate, 12–20 mm long, 2–3 mm wide, very narrowly elliptic to linear, apex acuminate to acute, base broad and concave, green turning bright yellow, margins flat, recurved inwards in vivo, appressed-pubescent outside, appressed-pubescent inside; stamens 60 to 70, in ca. 5 rows, ca. 1 mm long, broad; connective discoid, glabrous, green; staminodes absent; carpels free, 8 to 10, ovary ca. 1 mm long, stigma capitate, glabrous. Monocarps sessile, 5 to 11, 12–15 mm long, 5–6 mm in diameter, ellipsoid to fusiform, apex apiculate, glabrous, smooth, not ribbed, red when ripe; seeds 1 to 2 per monocarp, 10–12 mm long, 5 mm in diameter, ellipsoid to oblong; aril absent.

Figure 16. 

Artabotrys rufus A leaf, upper side B base of leaf blade, upper side C base of leaf bade, lower side D branch, note erect hairs E flowering branch F flower, side view G detail of receptacle, 4 petals removed H flower, top view A–H Couvreur 854, Gabon. Photos Thomas L.P. Couvreur.

Distribution

A mainly central African species, from Benin to Nigeria and Cameroon to the Republic of the Congo and in the Democratic Republic of the Congo; in Cameroon known from the Central and East regions.

Habitat

A fairly common species, in secondary lowland or premontane rain forests. Altitude 400–900 m a.s.l.

Local and common names known in Cameroon

nginda (pygmée–bibaya) (Letouzey 1964).

IUCN conservation status

Not evaluated.

Uses in Cameroon

None recorded.

Notes

Artabotrys rufus is distinguished by the hirsute pubescence of the young foliate branches, petioles, peduncles and flowering pedicels, its leaves that are elliptic, apiculate and less than 14 cm long, with long (1–2 mm) appressed hairs on the lower side of the leaf blade and a rounded to subcordate or obtuse base, a short peduncle (generally less than 7 mm long), petals with long dense brown hairs and smooth apiculate monocarps. The tertiary venation is also clearly visible forming clear loops towards the margins of the leaves.

Artabotrys rufus resembles A. velutinus being pubescent, but the pubescence of A. velutinus is not hirsute, with shorter hairs and more tomentose on the young foliate branches and petioles. The petals are also very similar being curved inwards, giving them the appearance of a tube. It is possible that both names are synonymous. Artabotrys rufus is also very close morphologically to the west African species A. hispidus Sprague & Hutch. by its hirsute pubescence and the shape of the leaves and flowers. It is also very possible that these names are synonymous. Several specimens from Cameroon where identified as A. hispidus, but upon closer look we have identified them as belonging to A. rufus. Several authors (Boutique 1951b; Le Thomas 1969b) have suggested that the name A. rufus might be synonym with the east African A. rupestris Diels, although Verdcourt didn’t recognize this synonymy (Verdcourt 1971a) suggesting differences in the leaves.

We here synonymize the names A. boonei and A. dahomensis with A. rufus. The former name was considered a synonym of A. velutinus (Lebrun and Stork 1991), but the type clearly suggests it is a synonym of A. rufus (if the latter is really distinct from A. velutinus).

Figure 17. 

Artabotrys thomsonii A flowering branch B outer petal, inner view C inner petal, inner view D flowering receptacle, petals removed E stamens, front and side views F carpel, side and detail of ovules G fruiting peduncle. Artabotrys rufus H flowering branch I flowering receptacle with one outer petal removed J outer petals, outer view and inner views K inner petals, inner and outer views L flowering receptacle, petals removed M stamen N carpel, side view and detail of ovule O fruiting peduncle A–G from Le Testu 9249 H–N from Hall 3193; 15 from Hall 3528. Drawings by Hélène Lamourdedieu, Publications Scientifiques du Muséum national d’Histoire naturelle, Paris; modified from Le Thomas (1969b, pl. 23, p. 441 (A. rufus)).

More detailed studies across the range of these species (A. hispidus, A. rufus, A. rupestris and A. velutinus) are needed to determine if there is one single widespread species from west to east Africa (possibly with different infraspecific taxa), or if there are several different species possibly grouped into a species complex (Hawthorne and Jongkind 2006).

Specimens examined

Central Region: Fébé Mount, 3.91°N, 11.48°E, 30 March 1962, Breteler F.J. 2717 (A,BR,K,P,WAG,YA); Mont Mbam Minkon on trail 5 km from Nkol Nyada village On top of small hill, 3.97°N, 11.40°E, 21 March 2013, Couvreur T.L.P. 418 (MPU,WAG,YA); Nachtigal, 4.35°N, 11.63°E, 01 July 1964, de Wilde W.J.J.O 2779 (P,WAG,YA); Nkolbison, 3.88°N, 11.45°E, 02 November 1964, de Wilde W.J.J.O 3715 (BR,K,P,WAG); Left bank Sanaga river near Ferry Nachtigal ca 20 km N of Obala, 4.34°N, 11.64°E, 29 April 1965, Leeuwenberg A.J.M. 6011 (B,BR,C,K, MO,P,WAG,YA). East Region: Dimako, 4.38°N, 13.57°E, 02 August 1961, Breteler F.J. 1752 (P,YA); Bertoua 15 km along road to Deng Deng, 4.66°N, 13.63°E, 31 August 1961, Breteler F.J. 1825 (WAG); Bamékok (Batouri), 4.2°N, 14.15°E, 16 April 1962, Breteler F.J. 2825 (P,WAG); 60 km south of Yokadouma 5 km south of Maséa village, 3.10°N, 14.84°E, 06 March 2019, Couvreur T.L.P. 1211 (MPU,WAG,YA); A 25 km au NE de Bangé km 75 route Yokadouma-Moloundou, 3.02°N, 15.12°E, 25 May 1963, Letouzey R. 5147 (P,YA); Mbatika-Malen 20 km de Moloundou route Yokadouma 2.03°N, 15.22°E, 22 April 1971, Mezili P. 193 (P,YA); Moloundou near Lokomo Bumba and Bange, 2.08°N, 15.25°E, 26 January 1911, Mildbraed G.W.J. 4350 (B,HBG); Forêt inhabitée entre Yokaduma et Assobam, 3.52°N, 15.05°E, 24 April 1911, Mildbraed G.W.J. 4999 (B,HBG).

Artabotrys thomsonii Oliv., Fl. Trop. Afr. 1: 28, 1868

Figs 17, 18; Map 2I

Type

Nigeria. Cross River State; Old Calabar, Thomson W.C 25, Feb 1863: holotype: K[K000198871].

Description

Liana, 30 m tall, d.b.h. 10–20 cm. Indumentum of simple hairs; old leafless branches sparsely pubescent to glabrous, young foliate branches sparsely pubescent. Leaves: petiole 1–10 mm long, ca. 2 mm in diameter, pubescent to glabrous, slightly grooved, blade inserted on top of the petiole; blade 7–20 cm long, 5–10 cm wide, elliptic to oblong, apex acute to abruptly acuminate, acumen 0.5–1 cm long, base rounded to obtuse, coriaceous, below sparsely pubescent to glabrous when young, sparsely pubescent to glabrous when old, above glabrous when young and old, concolorous; midrib impressed, above densely pubescent to pubescent when young and old, below sparsely pubescent to glabrous when young and old; secondary veins 7 to 14 pairs, glabrous above; tertiary venation intermediate. Individuals bisexual; inflorescences ramiflorous on old leafless branches, leaf opposed. Flowers with 9 perianth parts in 3 whorls, 30 to 90 per inflorescence, hook-shaped peduncle 20–35 mm long; pedicel 10–20 mm long, ca. 1 mm in diameter, pubescent; in fruit 10–25 mm long, ca. 2 mm in diameter, pubescent; bracts several, basal with one towards the lower half of pedicel, soon falling, basal bracts ca. 1 mm long, ca. 1 mm wide; upper bract ca. 2 mm long, ca. 2 mm wide; sepals 3, valvate, free, 2–3 mm long, 2–3 mm wide, triangular, apex acute, base truncate, pubescent outside, glabrous inside, margins flat; petals free, sub equal; outer petals 3, 10–20 mm long, 2–3 mm wide, elliptic to narrowly elliptic, apex rounded to obtuse, base broad and concave, margins flat, not folded inwards, pubescent outside, pubescent with a glabrous base inside; inner petals 3, valvate, 12–16 mm long, 2–3 mm wide, narrowly elliptic, apex acute, base broad and concave, margins flat, not folded inwards, pubescent outside, pubescent inside; stamens 30 to 35, in 2 to 3 rows, ca. 1 mm long, cuneiform; connective discoid, glabrous; staminodes absent; carpels free, 4 to 10, ovary ca. 1 mm long, stigma coiled, sparsely pubescent. Monocarps stipitate, stipes 10–25 mm long, 2–3 mm in diameter; monocarps 1 to 7, 15–25 mm long, 12–15 mm in diameter, ellipsoid to obovoid, apex rounded, glabrous, smooth, not ribbed, green when ripe; seeds 1 (to 2) per monocarp, 10–15 mm long, 8–9 mm in diameter, ellipsoid; aril absent.

Distribution

A central African species; from Nigeria to Angola (Cabinda) and in the Democratic Republic of the Congo; in Cameroon known from the Central, East, Littoral, South, South-West and West regions.

Habitat

A common species, in lowland and premontane secondary or primary rain forests, along forests margins and in logging areas. Altitude 100–1000 m a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Not evaluated.

Uses in Cameroon

food : water drinken from stem; medicine: water/sap used for liver, genital stimulant/depressants, pregnancy, antiaborifacients.

Notes

Artabotrys thomsonii is easily distinguished by the densely pubescent upper midrib which is not found in any other Cameroonian species of Artabotrys.

There seems to be confusion around the type specimen of the name Artabotrys thomsonii. In the protologue, Oliver (1868, p. 28) indicates “Thomson !, Old Calabar” as the type. In the Flore du Gabon, Le Thomas (1969b) indicates that the type is Thomson s.n., and notes that the sheet deposited in Kew is a mixed collection: pro parte with the fruits and associated leaves belonging to a different species (see below). This corresponds to specimen K000198872, labeled as Thomson 2310. However, this collection belongs to Mann 2310 (interestingly Le Thomas didn’t mention the number when it is clearly indicated) and not Thomson 2310 as indicated. The Kew specimen is confusing because it clearly says “collected by Rev W. C. Thomson” followed by the number 2310 with no mention of Mann. However, the duplicate in B [B 10 0154054] says “Old Calabar River, G. Mann 1863” followed by the mention “same as [hard to read, personal interpretation] Rev. W. Thomson”. The specimen in P [P00363393] has an identical handwriting and text as the one in B, but also has the mention “from Rev. W. Thomson”. However, the handwriting (same as in other true Mann collections) and high number (+2000) suggest this is a Mann collection and thus not the type (Thomson W.C. collections are below 150 from what we can see in K).

The collection Thomson 25 is without doubt a Thomson collection with a printed label indicating “Collected at Old Calabar, by the Rev. W.C. Thomson” followed by “Presented by Professor Balfour, Dec; 1963”. Indeed, some specimens of Thomson were forwarded by Balfour to Kew (Oliver 1865, p. 156).

Figure 18. 

Artabotrys thomsonii A branch B base of leaf blade, upper side, note densely pubescent midrib and glabrous blade C base of leaf blade, lower side A–C Couvreur 751, Mindourou, Cameroon. Photos Thomas L.P. Couvreur.

For what it is worth, the fruit and leaves on Mann 2310 (K [K000198872] and P [P00363393]) appear to belong to Neostenanthera myristicifolia (Oliv.) Exell also present in Nigeria.

Specimens examined

Central Region: Yaoundé, 3.87°N, 11.52°E, 1896, Zenker G.A. 697 (P). East Region: Near Dimako 28 km SW of Bertoua, 4.38°N, 13.57°E, 01 August 1961, Breteler F.J. 1725 (BR,K,P,U,WAG,YA); Bertoua 6 km along road to Batouri and Betaré-Oya, 4.58°N, 13.68°E, 30 August 1961, Breteler F.J. 1797 (U,WAG,YA); 67 km south of Yokadouma 30 km after Ngato 15 km after river ALPICAM ‘base de vie’ then 40 km on forestry road starting 4 km before Maséa village, 3.08°N, 14.67°E, 08 March 2019, Couvreur T.L.P. 1230 (MPU,WAG,YA); Palisco forest consession 15 km along main road into consession, 3.52°N, 13.54°E, 27 March 2015, Couvreur T.L.P. 751 (WAG,YA); 20 km environ à l’ENE de Mikel village situé à 85 km au N de Moloundou sur la route de Yokadouma 2.81°N, 15.24°E, 23 February 1971, Letouzey R. 10413 (K,P,YA); Ndongo (Dja-Molundou), 2.58°N, 15.29°E, 18 March 1973, Letouzey R. 12240 (K,P,YA); Djouo (Somalomo), 3.32°N, 12.93°E, 26 February 1962, Letouzey R. 4435 (K,P,YA); A 8 km au SSW de Koso (village situé à 60 km au SSW de Batouri), 3.93°N, 14.17°E, 29 July 1963, Letouzey R. 5533 (P,YA); Entre Badekok et Mpan (50 km ENE de Lomié), 3.22°N, 15.02°E, 05 August 1963, Letouzey R. 5548 (P,YA). Littoral Region: 8 km W of Massok, 4.13°N, 10.47°E, 27 March 1965, Leeuwenberg A.J.M. 5201 (B,BR,C,GC,K,MO,P,UC,WAG,YA). South Region: Bitya near R Ja, 3.02°N, 12.37°E, 01 November 1922, Bates G.L. 1763 (P); Djoum North East Nkout Base of ridge, 2.55°N, 12.80°E, 05 December 2014, Cheek M. 17781 (K,WAG); Elephant Mont, 2.8°N, 10.01°E, 24 May 2001, van Andel T.R. 3459 (KRIBI,WAG,YA); Campo-Ma’an area 2.73°N, 9.873°E, 16 August 2001, van Andel T.R. 3872 (KRIBI,U,WAG); Nkuambe, 3.26°N, 10.46°E, 01 December 1914, Zenker G.A. 489 (P,WAG). South-West Region: Bayang Mbo Wildlife Sanctuary after Mbu river, 5.35°N, 9.497°E, 27 March 2016, Couvreur T.L.P. 1020 (WAG,YA); Ekombe, 4.48°N, 10.87°E, 16 January 1987, Etuge M. 485 (MO,P,WAG). West Region: Près Bandounga à 40 km au NW de Ndikinimeki, 4.98°N, 10.55°E, 12 February 1972, Letouzey R. 11200 (P,YA).

Artabotrys velutinus Scott Elliot, J. Linn. Soc., Bot. 30: 71, 1894

Fig. 15; Map 3A

= Artabotrys nigericus Hutch., Bull. Misc. Inform. Kew 10: 356, 1921. Type. Nigeria. Jos North, Naraguta, Lely H.V. 541, 17 Aug 1921: holotype: K[K000198866].

= Artabotrys stenopetalus Engl. Notizbl. Königl. Bot. Gart. Berlin 2: 300, 1899. Syn. nov. Type. Cameroon. South Region, Bipindi, Zenker G.A. 1222, 1896: holotype: B[B10 0154052]; isotypes: GOET[GOET005675]; HBG[HBG502541]; K[K000198862]; M[M0107912]; MO[MO-216860]; NY[NY00025832]; P[P00363384, P00363385]; S[S07-13456]; WAG[WAG0053235]; WU[WU0025887, WU0025888].

? Artabotrys stenopetalus var. parviflorus Pellegr., Mém. Soc. Linn. Normandie 26: 7, 1924. Type. Gabon. Nyanga, Tchibanga, Le Testu G.M.P.C. 1964, 6 Jan 1915: lectotype, sheet here designated: P[P00363379]; isotypes: EA[EA000002453, EA000002452]; K[K000198861]; LISC[LISC000375]; P[P00363378, P00363380].

= Artabotrys nitidus auct. Exell Jour. of Bot. 73 Supp. Polypet. Add.: 5, 1935 (non Diels) (specimens Gossweiler 5978 [COI00070298] and 7361 [COI00070297]).

Type

Sierre Leone: Northern Region; Falaba, Scott Elliot G.F. 5137, 5 Mar 1892: holotype: K[K000198865]; isotype: B[B 10 0154055].

Description

Liana, up to 10 m tall, d.b.h. up to 20 cm. Indumentum of simple hairs; old leafless branches sparsely pubescent, young foliate branches pubescent. Leaves: petiole 3–4 mm long, ca. 1 mm in diameter, pubescent to glabrous, grooved, blade inserted on the side of the petiole; blade 8–13 cm long, 4–5 cm wide, ovate to elliptic, apex acuminate to acute, acumen 1–1.5 cm long, base decurrent to acute, papyraceous, below pubescent to sparsely pubescent when young, glabrous when old, above pubescent when young, sparsely pubescent to glabrous when old, concolorous; midrib impressed, above glabrous when young and old, below densely pubescent to pubescent when young, glabrous to pubescent when old; secondary veins 8 to 12 pairs, glabrous above; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old leafless branches, leaf opposed. Flowers with 9 perianth parts in 3 whorls, 5 to 15 per inflorescence, hook-shaped peduncle 10–16 mm long; pedicel 2–10 mm long, ca. 1 mm in diameter, pubescent with appressed hairs; in fruit 10–20 mm long, ca. 1 mm in diameter, pubescent with appressed hairs; bracts 2, all basal, ca. 1 mm long, ca. 1 mm wide; sepals 3, valvate, free, 2–3 mm long, 2–3 mm wide, triangular, apex acute, base truncate, densely pubescent outside, glabrous inside, yellow and red at the base, margins flat; petals free, sub equal; outer petals 3, 5–15 mm long, 1–2 mm wide, linear, apex rounded, base broad and concave, margins flat but strongly recurved inwards forming a tube, densely pubescent outside, densely pubescent inside; inner petals 3, valvate, 5–15 mm long, 1–2 mm wide, linear, apex acute, base broad and concave, yellow and red at the base, margins flat but strongly recurved inwards forming a tube, tomentose outside, tomentose with a glabrous at base inside; stamens 15 to 22, in 2 rows, 1–2 mm long, oblong; connective discoid, glabrous; staminodes absent; carpels free, 7 to 12, ovary 1–2 mm long, stigma cylindrical, glabrous. Monocarps sessile, 4 to 9, 10–20 mm long, 10 mm in diameter, ellipsoid to obovoid, apex rounded, glabrous, smooth, faintly ribbed, color when ripe not seen; seeds 1 to 2 per monocarp, 5–7 mm long, 5 mm in diameter, flattened ellipsoid; aril absent.

Distribution

A west and central African species, from Sierra Leone to Nigeria and Cameroon to the Republic of the Congo and in the Democratic Republic of the Congo; in Cameroon known from the Adamaoua, Central, East, North, South, South-West, and West regions.

Habitat

A fairly common and widespread species; in secondary lowland premontane and montane rain forests, and in gallery forests occurring in the drier regions of the country, it is one of the few Annonaceae species (e.g. Monanthotaxis vulcanica; Xylopia africana) occurring above 2000 m in Cameroon. Altitude 400–2200 m a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Not evaluated.

Uses in Cameroon

medicine : water/sap/leaves used for liver, genital stimulant/depressants, pregnancy, antiaborifacients (as A. stenopetalus in Burkill 1985).

Map 3. 

A Artabotrys velutinus B Brieya fasciculata C Cleistopholis glauca D Cleistopholis myristiciflora E Cleistopholis patens F Cleistopholis staudtii G Dennettia tripetala H Duguetia barteri I Duguetia confinis. White borders represent region limits in Cameroon; green patches represent protected areas (see methods and Suppl. material 1: Fig. S1).

Notes

Artabotrys velutinus is characterized by having leaf bases that are decurrent or acute, pubescent branches and petioles with appressed hairs and densely pubescent petals that are tightly recurved forming a tube. This latter character is also found in A. rufus, but in this species the pubescence is hirsute rather than appressed and the base of the leaves is rounded. Nevertheless, both species are very close morphologically.

Artabotrys velutinus belongs to a large species complex of pubescent species with petals that are tightly recurved forming a tube. We synonymize here the name A. stenopetalus. Another species name that could also be synonym is the east African species A. monteiroae Oliv. (which would be the older name). More studies are needed across the range of these species to better define the limits of these taxa.

The variety A. stenopetalus var. parviflorus is interesting. The type specimen (Le Testu 1964) appears to have a raised and grooved midrib on the upper side of the leaf blades (only seen as a scan on jstor), which is quite uncommon for African Annonaceae (Couvreur 2009), and the leaves are narrowly elliptic (versus elliptic for the type variety). The flowers however have the characteristic tubular petals. Pellegrin (1924, p. 7) only cites some minor differences such as smaller flowers, an acute leaf base (but this is also the case for the type variety) and petals that are adnate between them. We leave this name as a synonym of A. velutinus but further studies should be done to properly interpret the status of this variety name.

Specimens examined

Adamaoua Region: Mbibol 40 km W de Ngaoundéré, 7.32°N, 13.58°E, 12 June 1977, Fotius G. 2660 (P,YA); Près Tekel (60 km NNO de Bagodo), 6.78°N, 13.17°E, 21 July 1966, Letouzey R. 7481 (P,YA); Boko 14 km Sud-Ouest de Ngaoundéré, 7.25°N, 13.5°E, 06 August 1981, van der Zon A.P.M. 1122 (WAG,YA). Central Region: Pentes orientales du mont Yangba (1473 m) près Nyafianga (42 km NNE de Bafia), 5.13°N, 11.35°E, 09 September 1966, Letouzey R. 7826 (K,P,YA). East Region: 27 km ENE de Mopwo (village situé au km 22 route Yokadouma-Batouri), 3.67°N, 15.08°E, 06 June 1963, Letouzey R. 5248 (K,P,YA). North Region: Mango, 8.42°N, 13.25°E, 21 July 1974, Fotius G. 2144 (YA). South Region: Rives du Ntem près du confluent de la Kye 16 km ESE d’Ambam, 2.25°N, 11.34°E, 01 February 1970, Letouzey R. 10040 (P); Bipindi, 3.08°N, 10.42°E, 3 April 1897, Zenker G.A. 1222 (B,P,WAG); Bipindi, 3.08°N, 10.42°E, 01 January 1913, Zenker G.A. 231 (P,U,WAG). South-West Region: Edip village to lake edip 2–3 km, 4.96°N, 9.65°E, 11 February 1998, Cheek M. 9143 (K,WAG,YA); Kodmin, 5°N, 9.7°E, 16 November 1998, Gosline W.G. 149 (K,YA); Bank of river Chide, 4.95°N, 9.72°E, 04 February 1998, Onana J.M. 523 (K,P,WAG,YA). West Region: Massif du Nkogam (2263 m) 25 km W de Foumban, 5.73°N, 10.67°E, 12 December 1974, Letouzey R. 13501 (P,YA).

Brieya De Wild., Repert. Spec. Nov. Regni Veg. 13: 383, 1914

Thomas L.P. Couvreur & Jean-Paul Ghogue

Type species

Brieya fasciculata De Wild.

Description

Same as species.

A genus with two species, one widespread and one restricted to northern Angola. One species in Cameroun, not endemic.

A genus easily confused with Piptostigma because of the characteristic inner petals being much longer than the outer ones in both genera, a unique feature among Cameroonian Annonaceae (Ghogue et al. 2017). However, sterile, Brieya is mainly distinguished by the lower number of secondary veins (less than 20 versus generally more than 20 in Pipostigma) and discolorous leaves being whitish below (versus concolourous in Piptostigma).

Taxonomy

Ghogue et al. (2017).

Brieya fasciculata De Wild., Repert. Spec. Nov. Regni Veg. 13: 384, 1914

Figs 19, 20; Map 3B

Piptostigma fasciculatum (De Wild.) Boutique ex Fries, In Engler A., Prantl K. (eds) Die Natürlichen Pflanzenfamilien 17aII: 115–116, 1959.

= Piptostigma aubrevillei Ghesq. ex. Aubrév.; Fl. For. Cote d’Ivoire 1: 98, 1936. Type. Ivory Coast. Mudjika, Aubréville A. 2115, 1932: lectotype, designated by Ghogue et al. (2017), p. 211: P[P02032149].

Type

Democratic Republic of the Congo. Bas-Congo; Kingamu, Ganda sumi, de Briey J. 66, 14–16 Oct 1911: lectotype, sheet here designated: BR[BR-S.P.880319]; isotypes: BR[BR0000008803252, BR0000008803245, BR0000008803191].

Description

Tree, 10–25 m tall, d.b.h. 16–50 cm; stilt roots or buttresses absent. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches pubescent. Leaves: petiole 2–5 mm long, ca. 2 mm in diameter, pubescent, grooved, blade inserted on top of the petiole; blade 12–24 cm long, 6–8 cm wide, obovate to oblanceolate, apex acuminate to obtuse, acumen 0.5–0.8 cm long, base cordate to obtuse, papyraceous, below glabrous to pubescent when young, glabrous to pubescent when old, above glabrous when young and old, discolorous, whitish below; midrib impressed, above pubescent when young and old, below pubescent when young and old; secondary veins 11 to 17 pairs, glabrous below; tertiary venation percurrent. Individuals bisexual; inflorescences ramiflorous on old leafless branches, axillary occurring on short peduncle-like bases 0–2 mm long. Flowers with 9 perianth parts in 3 whorls, 1 to 4 per inflorescence; pedicel 1–2 mm long, ca. 5 mm in diameter, pubescent; in fruit 15–25 mm long, 4–5 mm in diameter, glabrous; bracts 2, one basal and one upper towards the lower half of pedicel, basal bract 2–3 mm long, ca. 2 mm wide; upper bract ca. 1 mm long, ca. 2 mm wide; sepals 3, valvate, free, ca. 2 mm long, ca. 2 mm wide, ovate, apex acute, base truncate, brown, pubescent outside, glabrous inside, margins flat; petals free, outer petals shorter than inner; outer petals 3, sepal like, 1.5–2 mm long, 1.5 mm wide, ovate, apex acuminate, base truncate, light green, margins flat, pubescent outside, glabrous inside; inner petals 3, valvate, 38–108 mm long, 3–7 mm wide, linear, apex acute, base truncate, green, margins flat, pubescent inside, pubescent outside; stamens 30 to 40, in 4 to 5 rows, ca. 1 mm long, broad; connective discoid, glabrous, green; staminodes absent; carpels free, ca. 4, ovary ca. 2 mm long, stigma minute, densely pubescent. Monocarps sessile, 1 to 3, 42–46 mm long, 25–40 mm in diameter, ellipsoid, apex rounded, glabrous, smooth, fleshy, green when ripe; seeds 18 to 20 per monocarp, ca. 10 mm long, ca. 4 mm in diameter, ellipsoid; aril absent.

Distribution

From Côte d’Ivoire to Democratic Republic of the Congo and Angola; in Cameroon known from East, South, Centre, Littoral and South-West regions.

Habitat

A common species when present, in lowland to submontane rain forests in primary or secondary habitats. Altitude 250–810 m a.s.l.

Local and common names known in Cameroon

baouéfou à grandes feuilles (french) (Burkill 1985).

IUCN conservation status

Least Concern (LC) (Cosiaux et al. 2019e).

Uses in Cameroon

None recorded.

Notes

Brieya fasciculata is distinguished by its discolorous leaves, glaucous white below with a percurrent tertiary venation, its flowers occurring on reduced inflorescences with a short peduncle, the inner petals much longer than the outer ones, with the minute sepals and outer petals identical is shape and size, and its long green linear inner petals.

Specimens examined

Central Region: Près Ngong (25 km NE d’Edéa), 3.75°N, 10.98°E, 12 December 1973, Letouzey R. 12345 (P,YA). East Region: 68 km south of Yokadouma 30 km after Ngato 15 km after river ALPICAM ‘base de vie’ then 40 km on forestry road starting 4 km before Maséa village, 3.08°N, 14.66°E, 08 March 2019, Couvreur T.L.P. 1231 (MPU,WAG,YA); Batéka Malen 20 km NE de Moloundou, 2.15°N, 15.35°E, 23 April 1971, Letouzey R. 10718 (P,YA); Entre Asip et Mang (60 km ENE de Lomié), 3.4°N, 14.17°E, 13 August 1963, Letouzey R. 5605 (P,YA). North-West Region: Kagwene, 6.10°N, 9.744°E, 13 June 2009, Ashworth J. 310 (K,YA). South Region: Campo Ma’an National Park 11 km on trail from Ebinanemeyong village on road 7 km from Nyabessan to Campo town, 2.48°N, 10.34°E, 11 February 2015, Couvreur T.L.P. 677 (WAG,YA); Abords de la Lobé à 50 km au SSE de Kribi et à 30 km à l’ENE de Campo, 2.51°N, 9.82°E, 23 March 1968, Letouzey R. 9132 (YA). South-West Region: Mudjika (Wudjika?), 4.29°N, 9.41°E, 01 January 1933, Aubréville A. 2115 (P); on trail from Ekongo village located 5 km before the entrance to Limbe 7 km on secondary road On flank of Mt Etinde 100 m in Mont Cameroon National Park, 4.07°N, 9.132°E, 16 October 2013, Couvreur T.L.P. 510 (WAG,YA); on trail from Ekongo village located 5 km before the entrance to Limbe 7 km on secondary road On flank of Mt Etinde 100 m in Mont Cameroon National Park, 4.07°N, 9.131°E, 16 October 2013, Couvreur T.L.P. 511 (WAG,YA); Rumpi mountains forest trail ca 5 km after Dikome Balue village ca 40 km north of Kumba, 4.93°N, 9.240°E, 10 January 2016, Couvreur T.L.P. 957 (WAG,YA); Kupe village Muanezum trail = Daniel Ajang’s Earthwatch rented area Mt 4.76°N, 9.666°E, 28 March 1996, Etuge M. 1844 (K); Kupe village, 4.77°N, 9.688°E, 28 November 1999, Gosline W.G. 234 (K); Njonji, 4.11°N, 9.016°E, 21 April 1997, Nning J. 385 (K,YA); Cameroon Mountain, 4.12°N, 9.028°E, 20 June 2001, van Andel T.R. 3732 (U,WAG).

Figure 19. 

Brieya fasciculata A flowering branch B flower, bottom view C flower, top view D detail of receptacle, all petals removed E longitudinal section of receptacle F stamen G carpel, side view and detail of ovules A from Aubréville 1500 B–G from Hallé 3166; 8 from Germain 2396. Drawings by Hélène Lamourdedieu, Publications Scientifiques du Muséum national d’Histoire naturelle, Paris; modified from Le Thomas (1969b, pl. 22, p. 127).

Figure 20. 

Brieya fasciculata A habit B leaf, upper side C leaf base, upper side D detail of leaf blade and venation; lower side E flower F detail of minute sepals and outer petal, in contrast to long inner petals G detail of receptacle H fruit with a single monocarp (others have fallen) A, H Couvreur 645, Mambe, Cameroon B, C no voucher, Rumpi Mountains, Cameroon D–G Couvreur 510, Mt Etinde, Cameroon. Photos Thomas L.P. Couvreur.

Cleistopholis Pierre ex Engl., Nat. Pflanzenfam. Nachtr. I: 160, 1897

Thomas L.P. Couvreur

Type species

Cleistopholis glauca Pierre ex Engl. & Diels.

Description

Trees, 15–35 m tall, d.b.h. 30–80 cm; stilt roots or buttresses absent, trunk white or brown. Indumentum of simple hairs when present, but species generally glabrous. Leaves: petiole 3–20 mm long, 1–3 mm in diameter, blade 4.5–31 cm long, 2–6.5 cm wide, elliptic to obovate to oblong, apex acuminate, base acute to rounded, discolorous, whitish below or concolorous; midrib sunken or flat; secondary veins 8 to 24 pairs; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old or young foliate branches, axillary, occurring or not on a short peduncle. Flowers with 9 perianth parts in 3 whorls, 2 to 9 per inflorescence; pedicel 10–25 mm long; in fruit 15–35 mm long; bracts 2 to 3, all basal, 1–2 mm long; sepals 3, valvate, free, 2–3 mm long, triangular to ovate, apex acute, sometimes rounded, base truncate; petals free; outer petals longer than inner; outer petals 3, valvate, 7–20 mm long, 2–7 mm wide, oblong to elliptic to obovate to linear, apex acute to rounded to obtuse, base truncate; inner petals 3, imbricate, 2–4 mm long, 2–4 mm wide, ovate to suborbicular, apex acute to obtuse, base truncate; stamens 20 to 40, in 3 to 4 rows, ca. 1 mm long, broad; connective discoid, glabrous; staminodes absent; carpels free, 10 to 24, ca. 1 mm long, stigma flat to capitate, glabrous. Monocarps stipitate, stipes 1–50 mm long, 3 to 18 monocarps, 15–30 mm long, 10–25 mm in diameter, globose to ellipsoid to obovoid, apex rounded, smooth, bumpy or constricted around the seeds, glabrous; seeds 1 to 2, 12–25 mm long, 8–12 mm in diameter, ellipsoid; aril absent.

A genus with four accepted species, two widespread, one known only from Cameroon and Gabon and one from Equatorial Guinea and possibly Cameroon. Three (four?) species in Cameroun, none endemic.

Taxonomy

None to date, but partial treated in this present work and Le Thomas (1969b).

Key to the species of Cleistopholis in Cameroon (vegetative characters of C. myristiciflora are taken from label information)

1 Trunk brown, petioles ca. 3 mm long; monocarps with stipes 49–50 mm long, thing, ca. 1 mm in diameter C. myristiciflora
Turk white, petioles generally 10–20 mm long (in C. patens can be as short as 3 mm too); monocarps with stipes 1–30 mm long, thick, 2–3 mm in diameter 2
2 Inflorescences with a distinct peduncule; monocarps ellipsoid to obovoid, drying smooth; lower leaf side glaucous, at least when fresh C. glauca
Inflorescences fasciculate, without a peduncule; monocarps globose to bilobed; lower leaf side not glaucous 3
3 Outer petals linear, 15–20 mm long; monocarps drying smooth, not bumpy; petiole 10–15 mm long C. staudtii
Outer petals oblong, elliptic or obovate, 7–12 mm long; monocarps bumpy, constricted around the seeds; petiole 3–12 mm long C. patens

Cleistopholis glauca Pierre ex Engl. & Diels, Monogr. Afrik. Pflanzen.-Fam. 6: 35, 1901

Figs 21, 23; Map 3C

= Cleistopholis grandiflora De Wild., Ann. Mus. Congo Belge, Bot. sér. 5, 1(1): 39, 1903. Type. Democratic Republic of the Congo. Kinshasa, Région de Kimuenza, Gérard P. s.n., Oct 1900: lectotype, sheet here designated: BR[BR0000008820327]; isotype: BR[BR0000008820655].

= Cleistopholis bequaertii De Wild., Pl. Bequaert. i.; 464, 1922. Type. Democratic Republic of the Congo. Nord-Kivu, Walikale - Lubutu, Bequaert J.C.C. 6624, 15 Jan 1915: lectotype, sheet here designated: BR[BR0000008820402]; isotype: BR[BR0000008820396].

Type

Gabon. Estuaire; Libreville, Klaine T.-J. 376, Apr 1896: holotype: B[B 10 0154073]; isotypes: K[K000198885, K000198884]; P[P00362650, P00362649, P00362652]; MPU[MPU011662].

Description

Tree, 10–35 m tall, d.b.h. 80 cm; stilt roots or buttresses absent. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches glabrous. Leaves: petiole 10–20 mm long, 1–2 mm in diameter, glabrous, grooved, blade inserted on the side of the petiole; blade 5–15 cm long, 2–5 cm wide, oblong to elliptic, apex acuminate, acumen 0.5–1.5 cm long, base decurrent to cuneate, subcoriaceous, below glabrous when young and old, above glabrous when young and old, discolorous, whitish below; midrib impressed, above glabrous when young and old, below glabrous when young and old; secondary veins 8 to 15 pairs, glabrous below; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on young and old leafless branches, axillary, peduncule distinct 2–10 mm long. Flowers with 9 perianth parts in 3 whorls, 2 to 8 per inflorescence; pedicel 10–18 mm long, ca. 1 mm in diameter, sparsely pubescent; in fruit 15–35 mm long, 2–3 mm in diameter, glabrous; bracts 1 to 3, all basal, basal bracts 1–2 mm long, 2 mm wide; sepals 3, valvate, free, ca. 2 mm long, ca. 2 mm wide, triangular to ovate, apex acute, base truncate, green, glabrous outside, glabrous inside, margins flat; petals free; outer petals 3, 10–15 mm long, 5–7 mm wide, oblong to elliptic, apex rounded, base truncate, green, margins flat, glabrous outside, glabrous inside; inner petals 3, imbricate, 2–4 mm long, 2–4 mm wide, ovate to orbicular, apex rounded, base truncate, green, margins flat, glabrous outside, glabrous inside; stamens 20 to 30, in 3 to 4 rows, ca. 1 mm long, broad; connective discoid, glabrous, green; staminodes absent; carpels free, 12 to 24, ovary ca. 1 mm long, stigma flat, glabrous. Monocarps stipitate, stipe 18–30 mm long, 3–4 mm in diameter; monocarps 3 to 8, 18–30 mm long, 10–15 mm in diameter, obovoid, apex rounded, glabrous, finely warty, not bumpy, green when ripe; seed (1 to) 2 per monocarp, 15–25 mm long, 10–12 mm in diameter, ellipsoid; aril absent.

Distribution

Central Africa; from Cameroon to Democratic Republic of the Congo; in Cameroon known from South, Central, Littoral, South-West and East regions, with one collection from Adamaoua region.

Figure 21. 

Cleistopholis glauca A flowering branch, note long petioles B detail of inflorescence C flower, top view, note imbricate inner petals D internal petal, inner view E detail of receptacle, top view F stamen, front and side views G carpel, side view and view of ovules H fruit, note smooth monocarps I longitudinal section of seed A–G from Le Testu 8786; 8 from Klaine 41. Drawings by Hélène Lamourdedieu, Publications Scientifiques du Muséum national d’Histoire naturelle, Paris; modified from Le Thomas (1969b, pl. 15, p. 89).

Habitat

A very common species, mainly growing as a pioneer species in disturbed areas and along forest margins. Altitude 100–1200 m a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Least Concern (LC) (Cosiaux et al. 2019f).

Uses in Cameroon

None recorded.

Notes

Closely resembles C. patens, see below for differences.

Specimens examined

Adamaoua Region: A 80 km au SO de Banyo-Plaine Tikar, 6.75°N, 11.82°E, 27 June 1969, Biholong M. 219 (P,YA). Central Region: Feup (Yaoundé), 3.87°N, 11.52°E, 01 July 1917, Chevalier A.J.B. 33473 (P,WAG); near Ebolbom village 3 km est of Ngoumou 2 km north west of Otélé, 3.59°N, 11.28°E, 02 May 2013, Couvreur T.L.P. 430 (MPU,WAG,YA); Avom, 3.87°N, 11.52°E, 01 January 1935, Foury P. 57 (P). East Region: Bertoua, 4.58°N, 13.68°E, 17 February 1960, Letouzey R. 3036 (P,YA); Région de Moloundou, 2.05°N, 15.17°E, 01 August 1949, SRFK 1372 (P,YA). Littoral Region: 18 km SEof Douala along road to Ndonga (=old to Edea), 4.05°N, 9.71°E, 20 August 1965, Leeuwenberg A.J.M. 6467 (B,BR,C,GC,K,L,LUAI,MO,P,UC,WAG,YA). South Region: 20 km from Kribi Lolodorf road, 3.05°N, 10.05°E, 09 June 1969, Bos J.J. 4784 (B,BR,K,LD,LM,MO,P,POZG,WAG,YA); on road between Campo and Kribi, 2.62°N, 9.847°E, 16 February 2012, Couvreur T.L.P. 389 (WAG,YA); Rocher du Loup km 36 road Kribi-Campo, 2.61°N, 9.85°E, 06 January 1983, de Kruif A.P.M. 1046 (MO,WAG,YA); Campo-Ma’an area 2.73°N, 9.873°E, 13 August 2001, van Andel T.R. 3846 (KRIBI,WAG,YA). South-West Region: Mungo River F.R., 4.78°N, 9.566°E, 02 December 1999, Cheek M. 10229 (K,MO,P,WAG,YA); Ntali, 5.25°N, 9.576°E, 01 December 2000, Etuge M. 4873 (K); Nyandong-forest above village, 4.98°N, 9.585°E, 20 March 2003, Etuge M. 4917 (K); Forest and forest relictss near Mundemba, 4.96°N, 8.916°E, 16 January 1985, Thomas D.W. 4200 (P); Near Mundemba town, 4.96°N, 8.916°E, 12 May 1986, Thomas D.W. 6121 (MO,P,WAG,YA).

Cleistopholis myristiciflora Diels & Mildbr., Bot. Jahrb. Syst. 53(3–5): 439 (1915)

Map 3D

Type

Cameroon. South Region(?) or Equatorial Guinea. Río Muni; Campo-Gebiet; Bebao[i?], Weg nach Olonga [Manga?], Tessmann, G. 767, 6 Jan. 1909: holotype: B[B 10 0154074].

Description

Tree, to 19 m tall, d.b.h. to 16 cm; stilt roots or buttresses absent, trunk brown. Indumentum of simple hairs (?); old leafless branches glabrous, young foliate branches pubescent (?). Leaves: petiole ca. 3 mm long, ca. 1 mm in diameter, pubescent (?), grooved, blade inserted on the side of the petiole; blade 8–12 cm long, ca. 4 cm wide, elliptic to oblong, apex acuminate, acumen ca. 1.5 cm long, base cuneate, papyraceous, below pubescent when young (?), glabrous when old, above glabrous when young and old, concolorous; midrib impressed, above glabrous when young and old, below pubescent when young (?), glabrous when old; secondary veins 10 to 13 pairs, glabrous below; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on young and old leafless branches, axillary, peduncule generally absent. Flowers with 9 perianth parts in 3 whorls, 4 to 9 per inflorescence, pedicel 15–27 mm long, ca. 1 mm in diameter, sparsely pubescent (?); in fruit ca. 20 mm long, 2–3 mm in diameter, glabrous (?); bracts not seen (soon falling ?); sepals 3, valvate, free, 1.5–2 mm long, ca. 1.5 mm wide, circular, apex rounded, base rounded, color unknown, pubescence not observed, margins flat; petals free; outer petals 3, valvate, 5–7 mm long, 2–3 mm wide, broadly elliptic to oblong, apex rounded, base truncate, color unknown, margins flat or wavy when dry, pubescence not observed; inner petals 3, imbricate (?), dimensions and shape not observed; stamens number not counted, row number not counted, ca. 1 mm long, broad; connective discoid, pubescence not observed, color unknown; staminodes absent (?); carpels free, 10 to 15 (?, possibly more based on the number of monocarps counted), ovary ca. 1.5 mm long, stigma flat, glabrous. Monocarps stipitate, stipes 49–50 mm long, ca. 1 mm in diameter; monocarps 17 to 18, 10–15 mm long, 10–15 mm in diameter, globose, apex rounded, glabrous (?), bumpy; seeds not seen.

Distribution

Equatorial Guinea and Cameroon (?); if present in Cameroon then from South region.

Habitat

A rare species, in primary submontane tierra firme forest. Altitude 750–850 m a.s.l. (altitude in Equatorial Guinea).

Local and common names known in Cameroon

Akom (Equatorial Guinea) (Guinea López 1946).

IUCN conservation status

No assessed, but probably CR.

Uses in Cameroon

None recorded.

Notes

Cleistopholis myristiciflora (initially known only from the type; Tessmann 767 (B, but see below)) was originally described as being from Cameroon (Diels 1915) with the type locality written as “Kamerun: Campo-Gebiet; Bebao[i?], Weg nach Olonga [Manga?]”. This locality information, however, is also found on several other of Günther Tessmann (1884–1969) specimens (e.g. 779, 800), collected between end 1908 and early 1909 but are suggested to be from Equatorial Guinea rather than Cameroon. Tessmann is suggested to have collected around 700 specimens in Equatorial Guinea between the island of Bioko and mainland Río Muni (Fero 2013). Le Thomas (1969b) also suggested this species is from Equatorial Guinea and is cited in the check list of plants in “Ensayo geobotánico de la Guinea continental Española” (Guinea López 1946). It was however not cited in the “Les arbres de la Guinée Équatoriale” (Wilks et al. 2000). Fero indicates that they did not locate any specimens of this species in Equatorial Guinea in the herbaria of BATA, LISU, MA and WAG, but suggest it should be present (Fero 2013). In Tessmann’s book about the Pangwe culture (Tessmann 1913), the name “Bébai” is found several times and is suggested to be at the border between Equatorial Guinea and Cameroon (page XXI). There is a map in the book (page 1) showing a village named Bébai, almost exactly on the border between Equatorial Guinea and Cameroon. Thus, evidence for its presence in Cameroon is still doubtful with no recent collections in Cameroon but two recent ones from Equatorial Guinea (see below). We include it in our taxonomic treatment as tentatively occurring in Cameroon and provide a tentative coordinate for Bebai in the map of this species.

The taxonomic affinities of this species were unclear for some time but suggested to be conspecific with either C. patens or C. staudtii. Le Thomas (1969b) notes that it has morphological characters of both C. patens (shape of the petals and number of carpels) and C. staudtii (leaf shape and venation), the later also suggested by Diels and Mildbrand (1915).

Recently, we located two specimens collected from Monte Alén in Guinea Equatorial (Senterre & Obiang 2939, 3699, BRLU) which appear to belong to C. myristicifolia (identified as such by B. Senterre). The leaves match the description and the type specimen, especially the shape and the length of the petiole being shorter (ca. 3 mm) than in the other species (> 3 mm). One specimen (Senterre & Obiang 2939), is in fruit. This single fruit is morphologically quite different than those of the other species in Cleistopholis. It is partially described here for the first time. The main difference is the length and diameter of the stipes being much longer and thinner than those from the other three species (49–50 mm long and ca. 1 mm in diameter versus 1–30 mm and 2–3 m in diameter). The number of monocarps appears to be higher with 17 to 18 counted in Senterre & Obiang 2939, versus 3 to 8 in the other species. These observations strongly support the hypothesis that C. myristiciflora is indeed a distinct and valid species. In terms of its ecology, observations from Senterre & Obiang suggest it to occur in primary submontane rain forests, occurring on gentle slopes or top of small mountains.

One specimen collected from southern coastal Gabon (Bergen 217 [WAG.1379499, WAG.1379500]) at 10 m a.s.l. was identified as C. myristiciflora by M. Fero. It is true that the inflorescences and flowers could potentially match, but the size of the tree (8 m) and leaves are different having a long petiole (> 3 mm). The ecology is also different than described above occurring along the coast on laterite soil. For now we do not consider this specimen as part of C. myristiciflora and Bergen 217 could potentially represent an undescribed Gabonese coastal species, as has been done recently in other Annonaceae genera such as Greenwayodendron littorale Lissambou, Dauby & Couvreur (Lissambou et al. 2018).

Cleistopholis patens (Benth.) Engl. & Diels, Monogr. Afrik. Pflanzen.-Fam. 6: 35, 1901

Figs 22, 23; Map 3E

Oxymitra patens Benth., Trans. Linn. Soc. London 23(3): 472, 1862.

= Cleistopholis brevipetala Exell, J. Bot. 70 (Suppl. 1): 208, 1932. Type. Angola. Cabinda, Gossweiler J. 6082, 31 Dec 1915: holotype: BM[BM000546899]; isotypes: COI[COI00004874]; LISC[LISC000068, LISC000071, LISC000069, LISC000070].

= Cleistopholis klaineana Pierre ex Engl. & Diels, Monogr. Afrik. Pflanzen.-Fam. 6: 35, 1901, Cleistopholis patens var. klaineana Pellegr., Bull. Soc. Bot. France: 57, 1949.. Type. Gabon. Estuaire, Libreville, Klaine T.J. 345, 1896: holotype: B[B 10 0154075]; isotypes: P[P00362660, P00362656].

= Cleistopholis lucens De Wild., Pl. Bequaert. i. 465, 1922. Type. Democratic Republic of the Congo. Nord-Kivu, entre Walikale et Lubutu, Bequaert J. 2774, 22 Fev 1922: holotype: BR[BR0000008820426].

= Cleistopholis pynaertii De Wild., Bull. Jard. Bot. État Bruxelles 4: 387, 1914. Type. Democratic Republic of the Congo. Equateur, Eala, Pynaert L.A. 1083, 1 Fev 1907: lectotype, sheet here designated: BR[BR0000008820419]; isotypes: BR[BR0000008820761, BR0000008820754].

= Cleistopholis verschuereni De Wild., Bull. Jard. Bot. État Brux. 4: 387, 1914. Type. Democratic Republic of the Congo. Manie Malela, Verschueren R. 358, Fev 1913: lectotype, sheet here designated: BR[BR0000008820389]; isotype: BR[BR0000008820433].

Type

Sierra Leone. Northern Region; Bagroo River, Mann G. 828, Apr 1861: lectotype, sheet here designed: K[K000880416]; isotypes: K[K000880417]; P[P00362653].

Description

Tree, up to 30 m tall, d.b.h. up to 60 cm; stilt roots or buttresses absent. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches glabrous. Leaves: petiole (3–)10–20 mm long, ca. 2 mm in diameter, glabrous, grooved, blade inserted on the side of the petiole; blade 4.5–31 cm long, 2.5–6 cm wide, oblong to narrowly oblong or oblanceolate to narrowly oblanceolate, apex acute to acuminate, acumen 1–1.5 cm long, base cuneate to rounded, coriaceous, above glabrous when young and old, shiny when dry, below glabrous when young and old, green, concolorous; midrib impressed, above glabrous when young and old, below glabrous when young and old; secondary veins 10 to 24 pairs, glabrous below; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on young or old leafless branches, axillary, peduncle absent. Flowers with 9 perianth parts in 3 whorls, 2 to 9 per inflorescence; pedicel 10–25 mm long, ca. 1 mm in diameter, glabrous; in fruit 15–30 mm long, 2–3 mm in diameter, glabrous; bracts 1 to 3, all basal, 1–2 mm long, ca. 2 mm wide; sepals 3, valvate, free, 2–3 mm long, ca. 2 mm wide, triangular to ovate, apex acute, base truncate, green, glabrous outside, glabrous inside, margins flat; petals free; outer petals longer than inner; outer petals 3, 7–12 mm long, 2–4 mm wide, obovate to oblong, apex obtuse, base truncate, green, margins flat, glabrous outside, glabrous inside; inner petals 3, imbricate, 3–4 mm long, 2–3 mm wide, ovate to suborbicular, apex rounded, base truncate, green, margins flat, glabrous outside, glabrous inside; stamens 25 to 30, in 3 to 4 rows, ca. 1 mm long, broad; connective discoid, pubescent, green; staminodes absent; carpels free, ca. 10, ovary ca. 1 mm long, stigma capitate, glabrous. Monocarps stipitate (sometimes shortly so), stipes 3–12 mm long, 3–4 mm in diameter; monocarps 3 to 6, 15–23 mm long, 11–25 mm in diameter, ellipsoid to globose, apex rounded, glabrous, finely warty, constricted around seeds, bumpy; seeds 1 to 2 per monocarp, ca. 12 mm long, 8–9 mm in diameter, ellipsoid; aril absent.

Distribution

In West Africa, Senegal, Sierra Leone to Nigeria, and Central Africa from Cameroon to Uganda; in Cameroon known from South, Central, Littoral, South-West and East regions.

Figure 22. 

Cleistopholis staudtii A flowering branch B flower, side view, note linear outer petals C stamen, side view D carpel, side view and detail of ovules. Cleistopholis patens E flowering branch F flower, side view G stamen, side view H carpel, side view and detail of ovules I fruit; note bumpy monocarps A–D from Letouzey 4149 E–J from Chevalier 22379. Drawings by Hélène Lamourdedieu, Publications Scientifiques du Muséum national d’Histoire naturelle, Paris; modified from Le Thomas (1969b, pl. 16, p. 93).

Habitat

A very common species, mainly growing as a pioneer species in disturbed areas and along rain forest margins. Altitude 0–600 m a.s.l.

Local and common names known in Cameroon

avom, sobu (pygmée Bibaya) (Letouzey 1964).

IUCN conservation status

Least Concern (LC) (Cosiaux et al. 2019g).

Uses in Cameroon

medicine : bark used as pain-killers, against pulmonary troubles; leaves as vermifuges, fabrifuges; construction: building materials, furniture; dyes and tannins: astringents, insecticides, arachnicides; products: fiber, pulp, wood fire, exudations-gums, resins, farming, forestry, hunting and fishing apparatus, household, domestic and personal items, pastimes-carving, musical instruments; social: religion, superstitions, sayings, aphorisms.

Notes

Cleistopholis patens closely resembles C. glauca by the shape and aspect of the flowers and the overall vegetative characters. However, both species differ by their inflorescences being pedunculate in C. glauca versus sessile, the leaves green below versus glaucous in C. glauca and the monocarps being bumpy and constricted around the seeds when dry versus to smooth and not bumpy when dry in C. glauca.

Specimens examined

Central Region: Avome, 3.87°N, 11.52°E, 13 August 1945, Aubréville A. 41 (P). East Region: 76 km south of Yokadouma 30 km after Ngato 15 km after river ALPICAM ‘base de vie’ then 40 km on forestry road starting 4 km before Maséa village, 3.15°N, 14.72°E, 05 March 2019, Couvreur T.L.P. 1202 (MPU,WAG,YA); Dja Reserve, 3.17°N, 13.18°E, 07 October 1994, Fogiel M.K. 947 (P); Deng Deng, 5.2°N, 13.51°E, 01 July 1939, Jacques-Félix H. 4630 (P,WAG); Rives de la Boumba à 14 km à l’WSW de Kinsassa village situé à 65 km au NNE de Moloundou sur route de Yokadouma 2.58°N, 15.26°E, 07 March 1971, Letouzey R. 10523 (P,YA). Littoral Region: km 19 Loum-Yabassi 3 km N of Solé, 4.61°N, 9.8°E, 30 December 1971, Leeuwenberg A.J.M. 9032 (YA,WAG). South-West Region: Southern Bakundu Forest Reserve, 4.55°N, 9.433°E, 15 June 1960, Adebusuyi J.K. 44049 (WAG); S Bakundu Forest 3 km from Kindongi Camp (8 km from road), 4.49°N, 9.374°E, 02 May 1972, Leeuwenberg A.J.M. 9785 (B,BR,C,K,M,MO,P,WAG,YA); 2 km W of km 21 Kumba-Victoria road, 4.46°N, 9.483°E, 04 May 1972, Leeuwenberg A.J.M. 9828 (B,BR,C,K,LD,M,MO,P,WAG,YA); Bibundi, 4.21°N, 8.988°E, 08 November 1928, Mildbraed G.W.J. 10640 (K); Korup National Park, 4.88°N, 8.783°E, 22 July 1983, Thomas D.W. 2329 (MO,P,WAG,YA); Limbe (Victoria), 4.01°N, 9.133°E, 25 October 1997, van der Burgt X.M. 219 (KRIBI,WAG).

Cleistopholis staudtii (Engl. & Diels) Engl. & Diels, Monogr. Afrik. Pflanzen.-Fam. 6: 35, 1901

Figs 22, 23; Map 3F

Oxymitra staudtii Engl. & Diels, Notizbl. Königl. Bot. Gart. Berlin 2: 297, 1899.

= Polyalthia (?) crassipes Engl. Bot. Jahrb. Syst. 34: 477, 1907. Type. Cameroon. South Region, Bipindi, Zenker G.A. 2454a, 1902: holotype B destroyed, lectotype here designated: P[01988941]; isolectotypes: MO[MO-2500050]; P[P01988940, P01988942].

Type

Cameroon. South-West Region; Johann-Albrechtshöhe [Kumba], Staudt A. 957, 1896: holotype: B[B 10 0154076]; isotypes: BM[BM000546890]; K[K000105343]; LE[LE00012452]

Description

Tree, 15–30 m tall, d.b.h. up to 30 cm; stilt roots or buttresses absent. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches glabrous. Leaves: petiole 10–20 mm long, ca. 3 mm in diameter, glabrous, grooved, blade inserted on the side of the petiole; blade 9–17 cm long, 3–6.5 cm wide, obovate, oblong to elliptic, apex acuminate, acumen ca. 1 cm long, base rounded to acute, coriaceous, below glabrous when young and old, above glabrous when young and old, discolorous, whitish below, midrib impressed, above glabrous when young and old, below glabrous when young and old; secondary veins 10 to 12 pairs, glabrous below; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on young and old leafless branches, axillary, peduncle absent. Flowers with 9 perianth parts in 3 whorls, 2 to 3 per inflorescence; pedicel 12–20 mm long, ca. 1 mm in diameter, glabrous; in fruit 15–35 mm long, ca. 3 mm in diameter, glabrous; bracts 1 to 3, all basal, 1–2 mm long, 2 mm wide; sepals 3, valvate, free, ca. 2 mm long, ca. 2 mm wide, triangular to ovate, apex acute to rounded, base truncate, green, glabrous outside, glabrous inside, margins flat; petals free, outer petals longer than inner; outer petals 3, 15–20 mm long, 2–3 mm wide, linear, apex acute, base truncate, green, margins flat, glabrous outside, glabrous inside; inner petals 3, imbricate, 2–2.5 mm long, 3–3.5 mm wide, ovate, apex acute, base truncate, claw mm long, green, margins flat, glabrous outside, glabrous inside; stamens 30 to 40, in 3 to 4 rows, ca. 1 mm long, broad; connective discoid, pubescent, green; staminodes absent; carpels free, 15 to 22, ca. 1 mm long, stigma capitate, glabrous. Monocarps stipitate to sessile, stipes when present to 10 mm long, 3–4 mm in diameter, 3 to 8 monocarps, 15–20 mm long, 12–15 mm in diameter, globose, apex rounded, glabrous, striate, bumpy, constricted around seeds; seeds 1 to 3 per monocarp, 10–15 mm long, 7–10 mm in diameter, ellipsoid; aril absent.

Distribution

From Cameroon to Gabon; in Cameroon known from South, Central, Littoral and South-West regions.

Habitat

A common species when present, in lowland rain forests in primary or secondary habitats. Altitude 50–1000 m a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Least Concern (LC) (Cosiaux et al. 2019h).

Uses in Cameroon

construction : bark for building materials (Tessmann 1913).

Notes

Easily distinguished from C. glauca and C. patens by its linear and acute outer petals, in contrast to short and rounded outer petals in the latter two. It is quite hard to distinguish these species based on sterile material alone.

Figure 23. 

Cleistopholis glauca A habit, note long drooping branches B flowers, top view, inner petals imbricate, not opened yet C fruit, note smooth monocarps D flowering branch, inner petals open revealing receptacle. Cleistopholis patens E trunk F base of leaf blades, upper view. Cleistopholis staudtii G leaf, top view, note long petioles H leaf, lower view I flowering branch, note long linear outer petals A–C Sosef 2036, Gabon D Couvreur 389, Ebodjé, Cameroon E, F Couvreur 1202, Maséa, Cameroon G–I Couvreur 570, Gabon. Photos Thomas L.P. Couvreur.

Specimens examined

Central Region: Ca 50 km NW of Eséka W of Yaoundé, 3.65°N, 10.78°E, 25 November 1963, de Wilde W.J.J.O 1342 (B,BR,C,DES,L,LD,MO,P,U,WAG,YA); Ottotomo Forest Reserve, 3.65°N, 11.31°E, Service Forestier du Cameroun 32 (P). South Region: ca 15 km from Kribi 1 km S of Ebolowa road, 2.85°N, 10.01°E, 20 February 1970, Bos J.J. 6383 (P,WAG); Station de cacaoyer de N’koemvone 14 km On the road from Ebolowa to Ambam, 2.81°N, 11.13°E, 02 February 1975, de Wilde J.J.F.E 7947 (B,BR,K,MO,P,U,WAG,YA); Près de Bella (45 km NE de Kribi), 3.25°N, 10.2°E, 25 January 1962, Letouzey R. 4149 (P,YA); Bipindi, 3.08°N, 10.41°E, 01 January 1900, Zenker G.A. 2264 (L,P,WAG); Bipindi, 3.08°N, 10.41°E, 01 January 1902, Zenker G.A. 2454 (L,P,WAG); Bipindi, 3.08°N, 10.41°E, 01 January 1902, Zenker G.A. 2495 (L,P,WAG); Bipindi, 3.08°N, 10.41°E, 01 January 1913, Zenker G.A. 4669 (L,P); Bipindi, 3.08°N, 10.41°E, 01 January 1913, Zenker G.A. 4880 (L,P). South-West Region: Ekundu Kundu, 5.16°N, 8.874°E, 11 April 1996, Cable S. 1825 (K,YA); Kupe Mount Path to Kupe Rock, 4.75°N, 9.686°E, 24 November 1995, Cheek M. 7915 (K,P,WAG); Muanezum trail from Kupe village towards Daniel Ajang’s area 4.77°N, 9.708°E, 18 July 1996, Etuge M. 2884 (K,MO,P,WAG); Just outside Kupe village going north, 4.77°N, 9.688°E, 29 November 1999, Gosline W.G. 240 (K,MO,P,WAG,YA); Korup National Park, 5.06°N, 8.855°E, 05 December 1997, Kenfack D. 984 (MO,P,WAG); Environs of Kumba farmed land and scrub with scattered trees, 4.63°N, 9.433°E, 01 March 1984, Thomas D.W. 3271 (MO,WAG,YA).

Dennettia Baker f., Cat. pl. Oban 5, t. 2. 1913

Léo-Paul M.J. Dagallier & Thomas L.P. Couvreur

Type species

Dennettia tripetala Baker f.

Description

Same as species.

A genus with a single widespread species from West Africa (Sierra Leone to Nigeria) and in Cameroon. One species in Cameroon, not endemic.

Dennettia was first described by Baker (1913) based on the bisexual flowers and inflorescences occurring on foliate branches. However, Kenfack et al. (2003) recombined the name Dennettia into Uvariopsis as Uvariopsis tripetala (Baker f.) G.E. Schatz based on a number of morphological characters. A molecular phylogenomic analysis of tribe Monodoreae (where this genus bellows) confirmed that Dennettia tripetala did not cluster with other species of Uvariopsis and should be regarded as a genus of its own (Dagallier et al. in prep).

Dennettia tripetala Baker f., Cat. Pl. Oban: 5, 1913

Fig. 24; Map 3G

Uvariopsis tripetala (Baker f.) G.E.Schatz, Novon 13(4): 447, 2003.

Type

Nigeria. Edo State; Benin City, Dennett R.E. 44, 1 Jan 1907: lectotype, designated by Kenfack et al. (2003), p. 447; sheet here designated: K[K000040959]; isolectotypes: K[K000040961]; S[S-G-9774].

Description

Shrub to small tree, 2–5 m tall, d.b.h. unknown; stilt roots or buttresses absent. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches glabrous to sparsely pubescent. Leaves: petiole 2–5 mm long, 1–2 mm in diameter, glabrous, slightly grooved, blade inserted on top of the petiole; blade 7.2–15.5 cm long, 3–6.8 cm wide, elliptic, apex attenuate to acuminate, acumen 0.6–1.3 cm long, base acute to decurrent, subcoriaceous, below glabrous when young and old, above glabrous when young and old; midrib sunken or flat, above glabrous when young and old, below glabrous when young and old; secondary veins 5 to 10 pairs per side, glabrous above; tertiary venation reticulate. Individuals bisexual, inflorescences ramiflorous on old leafless branches, axillary. Flowers with 6 perianth parts in 2 whorls, 1 to 4 per inflorescence; pedicel 4–9 mm long, 1–2 mm in diameter, pubescent; in fruit 5–15 mm long, 2–3 mm in diameter, glabrous to pubescent; bracts 1 to 3, all basal 0.5–2 mm long, 1.5–2 mm wide; sepals 3 (rarely 2), valvate, basally fused, 1–3 mm long, 1.5–4 mm wide, triangular, apex acute, base truncate, brown, pubescent outside, glabrous inside, margins flat; petals 3 (rarely 4, see notes), free, 7–14 mm long, 6–10 mm wide, broadly ovate, apex obtuse, base truncate, margins flat, pubescent outside, glabrous inside; stamens ca. 150, in 10 to 20 rows, 0.5–1 mm long, oblong; connective reduced or absent, glabrous; staminodes absent; carpels free, 8 to 30, ovary ca. 2–4.5 mm long, stigma globose, pubescent. Monocarps stipitate, stipes 1–3 mm long, ca. 1 mm in diameter; monocarps 1 to 8, 11–32 mm long, 5–15 mm in diameter, ovoid to oblong, apex rounded, glabrous to sparsely pubescent, verrucose, wrinkled; seeds 4 to 12 per monocarp, 4–10 mm long, 11–14 mm in diameter, ellipsoid; aril absent.

Figure 24. 

Dennetia tripetala A flowering branch B flower, petals remove, 1 sepal removed, showing receptacle C receptacle with stamens and stigmas D stamen, front view E carpel, front view F carpel, longitudinal section showing ovules. Material of drawings unknown. Author of drawings unknown, taken from Baker (1913; plate 2).

Distribution

Mainly a West African species from Sierra Leone to Cameroon; in Cameroon known from the South-West region.

Habitat

an uncommon species; in lowland to premontane primary or secondary rain forests. Altitude 0–1000 m a.s.l.

Local and common names known in Cameroon

Bushpèpè (Westphal 9932, Pidgin English(?)); Pepperfruit (english)

IUCN conservation status

Least Concern (LC) (Harvey-Brown 2019f) (as Uvariopsis tripetala).

Uses in Cameroon

food : fruit for sauces, condiments, spices, flavorings (pepper); medicine: cough, fever, toothache, diarrhea, diabetes, nausea (Iseghohi 2015).

Notes

Dennettia tripetala is unique in Cameroonian by being a tree with bisexual flowers having three sepals and three petals. This species resembles Uvariopsis congensis and Uvariopsis zenkeri (Uvariopsis being a genus were Dennettia was once part off, see above, Kenfack et al. (2003)) by the smaller dimensions of its leaves (7–18 cm long and 3–6 cm wide), and the small and short pedicellate (< 1 cm) flowers. Dennettia tripetala, however, differs from these two species by its bisexual flowers, whereas all other species of Uvariopsis in Cameroon have unisexual flowers. Only one other species of Uvariopsis is bisexual (U. bisexualis Verdc.) which occurs in East Africa (Verdcourt 1971a).

It has been reported that some D. tripetala specimens had 2 sepals and 4 petals (Kenfack et al. 2003), however, a recent morphological study did not find any evidence for that (Dagallier et al. in prep). However, we cannot exclude that it might be a rare event.

Specimens examined

South-West Region: Missellele, 4.12°N, 9.448°E, Box H.E. 3556 (BM,K); Limbe (Victoria), 4.07°N, 9.189°E, 01 April 1929, Maitland T.D. 626 (K); Buea area 4.2°N, 9.183°E, 01 January 1930, Maitland T.D. s.n. (K[K000105532]); Likomba-Pflanzung 15–35 km NE von Victoria [Limbe], 4.1°N, 9.333°E, 18 October 1928, Mildbraed G.W.J. 10515 (K); Ngandjo on Kumba Mbonge road, 4.55°N, 9.4°E, 25 February 1986, Thomas D.W. 5661 (K); Market of Victoria, 4.01°N, 9.2°E, 04 April 1978, Westphal E. 9932 (WAG).

Duguetia A. St.-Hil., Fl. Bras. Merid. (A. St.-Hil.), 1: 35, 1825

Thomas L.P. Couvreur

= Pachypodanthium Engl. & Diels, Notizbl. Königl. Bot. Gart. Berlin 3: 55, 1900.

Type species

Duguetia lanceolata A.St.-Hil. (a Brazilian species).

Description

Trees, 8–50 m tall, d.b.h. up to 50 cm; stilt roots or buttresses absent. Indumentum of stellate or fasciculate hairs. Leaves: petiole 1–10 mm long, 2–6 mm in diameter; blade 7–34 cm long, 3–8 cm wide, ovate to elliptic to obovate, apex acuminate to acute, acumen 0.5–1 cm long, base cordate to acute, discolorous, whitish below or concolorous; midrib sunken or flat; secondary veins 8 to 25 pairs; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on young and old leafless branches, leaf opposed or supra-axillary. Flowers with 9 perianth parts in 3 whorls, 2 to 5 per inflorescence; pedicel 3–22 mm long; in fruit 1–50 mm long; bracts 2, one basal and one upper in the lower half of pedicel, basal bract 7–12 mm long, upper bract similar than basal one; sepals 3, valvate, free, 6–15 mm long, apex acute, base truncate; petals free, outer petals longer than inner to sub equal; outer petals 3, valvate, free, 10–30 mm long, 4–10 mm wide, elliptic to ovate, apex acute to acuminate, base truncate; inner petals 3, imbricate, free, 4–20 mm long, 4–9 mm wide, elliptic to ovate to obovate, apex acute to acuminate, base truncate; stamens numerous, 1–2 mm long, broad; connective discoid; staminodes absent; carpels free, 50 to 125, 1.5–3.5 mm long, stigma globose. Fruit pseudosyncarpous; carpels sessile, connate or free, 60 to 125 carpels, 15–55 mm long, 7–30 mm in diameter, globose to ovoid to ellipsoid, apex domed-shaped to acute to apiculate; seed 1, 7–20 mm long, 4–13 mm in diameter, obovoid to ellipsoid; aril present, rudimentary.

A genus of 94 species, with a disjunct distribution, 89 in the Neotropics and 4 in Africa, but absent from Madagascar. All four African species are known from Cameroon, one endemic.

This genus of trees is characterized by stellate hairs on its leaves and pseudosyncarpous fruits. The only other tree genus with stellate hairs in Cameroon is Annickia, but the latter has a yellow slash and apocarpous fruits with clearly stipitate monocarps.

Taxonomy

Maas et al. (2003); present work.

Key to the species of Duguetia in Cameroon

1 Leaf blabes narrowly elliptic to narrowly oblong, 4 to 6 times longer than wide and leaves verruculose D. confinis
Lower side of the leaves sparsely to densely covered with appressed (flattened), stellate hairs; fruit globose or ovoid 2
2 Leaf base generally cordate, mid rid furrowed above, secondary veins weakly distinct D. staudtii
Leaf base acute, mid rid not furrowed above, secondary veins clearly distinct, forming loops 3
3 Inflorescences forming on a short peduncle in leafless parts of branches; fruiting carpels totally fused, areoles domed-shaped; seeds brown D. barteri
Inflorescences not forming a short peduncle in leafy part of branches; fruiting carpels basally fused, areoles obovoid to deltoid; seeds black D. dilabens

Duguetia barteri (Benth.) Chatrou, Changing Genera: 66, 1998

Fig. 25; Map 3H

Annona barteri Benth., Trans. Linn. Soc. London 23(3): 477, 1862.

= Pachypodanthium staudtii (Engl. & Diels) Engl. & Diels var. letestui Pellegr., Bull. Soc. Bot. France 95: 137, 1948. nom. illeg.

= Pachypodanthium tessmannii R.E.Fr., nom. nud.

Type

Nigeria. Anambra state; Onitsha, Barter C. 445, 1858: holotype: K[K000198875].

Description

Tree, 8–40 m tall, d.b.h. 40–60 cm; stilt roots or buttresses absent. Indumentum of stellate or fasciculate hairs; old leafless branches sparsely pubescent to glabrous, young foliate branches sparsely pubescent to densely pubescent. Leaves: petiole 3–7 mm long, 2–3 mm in diameter, densely to sparsely pubescent, grooved, blade inserted on the side of the petiole; blade 10–23 cm long, 3–7 cm wide, ovate to elliptic, apex acuminate to acute, acumen ca. 1 cm long, base cordate to acute, subcoriaceous, below densely pubescent when young and old, above glabrous when young and old, concolorous; midrib sunken or flat, not grooved, above glabrous when young and old, below densely pubescent when young and old; secondary veins 9 to 18 pairs, distinct, glabrous below; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old leafless branches, appearing axillary, forming on a short peduncle 4–10 mm long. Flowers with 9 perianth parts in 3 whorls, 2 to 5 per inflorescence; pedicel 11–22 mm long, 3–4 mm in diameter, sparsely to densely pubescent; in fruit 1–25 mm long, 1–4 mm in diameter, sparsely to densely pubescent; bracts 2, one basal and one upper in the lower half of pedicel, basal bracts 7–9 mm long; sepals 3, valvate, free, 10–15 mm long, 9–10 mm wide, ovate, apex acute, base truncate, yellowish green to greyish green, densely pubescent outside, glabrous inside, margins flat; petals free, outer petals longer than inner to sub equal; outer petals 3, 10–22 mm long, 5–8 mm wide, elliptic to ovate, apex acute, base truncate, cream to white, margins flat, sparsely pubescent outside, glabrous inside; inner petals 3, imbricate, 15–17 mm long, 4–5 mm wide, elliptic to ovate, apex acute, base truncate, cream, margins flat, pubescent outside, glabrous inside; stamens numerous, ca. 1 mm long, broad; connective discoid, glabrous, red; staminodes absent; carpels free, 50 to 75, ovary ca. 1.5 mm long, stigma globose, glabrous. Fruit pseudosyncarpous, 40–200 mm in diameter, globose to depressed ovoid; individual carpels sessile, 60 to 70 carpels, completely fused, ca. 15 mm long, ca. 7 mm in diameter, globose to ovoid, apex domed-shaped, densely pubescent, longitudinally ribbed with 5 to 6 main ribs, pinkish red when ripe; seed 1 per monocarp, 7–15 mm long, 4–7 mm in diameter, ellipsoid; aril present, pale yellow.

Figure 25. 

Duguetia barteri A flower, side view B flower, bottom view C fruit, note fused monocarps into a syncarpous fruit, referred to as a pseudosyncarp and with dome shaped apex D longitudinal section of fruit, note completely fused monocarps. Duguetia confinis E leaves, upper side F base of leaf blade, upper side G base of leaf blade, lower side, note whitish pubescence representing minute stellate hairs completely covering whole lower side of leaf blade H flowering branch I flower, top view J detail of receptacle, all petals removed A, B Sosef 2138, Gabon C, D Couvreur 393, Ngovayang, Cameroon E–J Couvreur 527, Gabon. Photos Thomas L.P. Couvreur.

Distribution

A central African species, from Cameroon to Gabon; in Cameroon known from East, South, Central, Littoral and South-West regions.

Habitat

In periodically or permanently inundated forests. Altitude 350–600 m a.s.l.

Local and common names known in Cameroon

ntom (dial. Bagali) (Letouzey 1964).

IUCN conservation status

Least Concern (LC) (Cosiaux et al. 2019i).

Uses in Cameroon

None recorded.

Notes

Duguetia barteri is distinguished by its elliptic to ovate leaves, the midrib not grooved above, inflorescences occurring on a short peduncle in leafless parts of the branches and its fruits with completely fused monocarps.

Specimens examined

Central Region: Bank of Nyong river 40 km SE of Yaoundé, 3.65°N, 10.78°E, 09 November 1961, Breteler F.J. 2013 (BR,K,P,WAG,YA); Abimoa, 3.57°N, 11.62°E, 04 April 1962, de Bruijn J. s.n. (WAG[WAG0175175]); Bordure du Nyong près du lac de Nkolmaka (près route Mbalmayo-Akonolinga), 3.51°N, 11.82°E, 22 April 1954, Letouzey R. 304 (P,YA). Littoral Region: Right bank Ouem river near mouth in Sanaga R 6 km SW of Massok, 4.13°N, 10.47°E, 04 April 1965, Leeuwenberg A.J.M. 5377 (BR,K,MO,P,WAG,YA); Tissongo study area 3.57°N, 9.869°E, 01 June 1976, Waterman P.G. 874 (K). South Region: mountain chain Ngovoyang 2 km in forest from Bikiliki village situated between Bipindi and Lolodorf, 3.18°N, 10.52°E, 18 February 2012, Couvreur T.L.P. 393 (WAG,YA); Campo-Ma’an National Park, 2.38°N, 10.06°E, 01 July 2001, van Andel T.R. 3810 (KRIBI,WAG,YA). South-West Region: Ekundu Kundu, 5.15°N, 8.883°E, 30 April 1996, Cheek M. 8274 (K,WAG,YA).

Duguetia confinis (Engl. & Diels) Chatrou, Changing Genera: 67, 1998

Figs 25, 26; Map 3I

Pachypodanthium confine Engl. & Diels, Notizbl. Konigl. Bot. Gart. Berlin 3: 55, 1900.

= Pachypodanthium sargosii R.E.Fr., Ark. Bot. 3(2): 38, 1955; Pachypodanthium confine var. sargosii Le Thomas, Fl. Gabon 16: 106, 1969. Type. Republic of Congo: Kouilou, Sargos R. 29, 4 Mar 1920: lectotype, sheet here designated: P[P00364784]; isotype: P[P00364785].

Type

Gabon. Estuaire; Libreville, Klaine T.-J. 217, 10 Oct 1895: lectotype, sheet here designated: P[P00315819]; isotypes: P[P00315821, P00315815].

Description

Tree, 15–40 m tall, d.b.h. 40–85 cm; stilt roots or buttresses absent. Indumentum of stellate hairs; old leafless branches sparsely pubescent to glabrous, young foliate branches densely pubescent. Leaves: petiole 1–8 mm long, 2–6 mm in diameter, densely pubescent, cylindrical, blade inserted on the side of the petiole; blade 9–31 cm long, 3–8 cm wide, elliptic, apex acute, acumen 0.5–1 cm long, base rounded to acute, coriaceous, below densely pubescent with white erect stellate hairs covering the whole blade when young and old, above glabrous when young and old, discolorous, whitish below; midrib sunken or flat, above glabrous when young and old, below densely pubescent when young and old; secondary veins 14 to 25 pairs, indistinct, glabrous below; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old leafless branches, appearing axillary, forming on a short peduncle 2–11 mm long. Flowers with 9 perianth parts in 3 whorls, 2 to 5 per inflorescence; pedicel 3–20 mm long, 2–5 mm in diameter, densely pubescent; in fruit 3–20 mm long, 2–5 mm in diameter, glabrous to densely pubescent; bracts 2, one basal and one towards the upper half of pedicel, basal bracts 5–9 mm long, 5–10 mm wide; sepals 3, valvate, free, 17–22 mm long, 13–15 mm wide, ovate, apex acute, base truncate, green, densely pubescent outside, glabrous inside, margins flat; petals free, outer petals longer than inner to sub equal; outer petals 3, 11–18 mm long, 5–9 mm wide, elliptic, apex acuminate, base truncate, cream to white, margins wavy, densely pubescent outside, glabrous inside; inner petals 3, imbricate, 11–18 mm long, 5–9 mm wide, elliptic, apex acuminate, base truncate, cream, margins flat, pubescent outside, glabrous inside; stamens 290 to 310, in 7 to 8 rows, 1–2 mm long, broad; connective discoid, glabrous, red; staminodes absent; carpels free, 100 to 125, ovary 1.4–2 mm long, stigma globose, glabrous. Fruit pseudosyncarpous, 25–50 mm in diameter, ellipsoid; individual carpels sessile, 100 to 125 carpels, completely fused, 15–12 mm long, 2–5 mm in diameter, obovoid, apex apiculate to acute, densely pubescent, longitudinally ribbed with 5 to 6 main ribs, greyish brown with purplish red or pale brown pulp when ripe; seed 1 per monocarp, 10–14 mm long, 4–8 mm in diameter, ellipsoid; aril present, red.

Distribution

From Cameroon to Gabon and Republic of Congo; in Cameroon known from East, South and Littoral regions.

Habitat

In lowland periodically inundated or non-inundated rain forests. Altitude 0–50 m a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Least Concern (LC) (Cosiaux et al. 2019j).

Uses in Cameroon

None recorded.

Notes

Duguetia confinis is distinguished by its lower leaf surface, which is densely pubescent with erect stellate hairs completely covering the blade, and its carpels completely fused in fruit.

Figure 26. 

Duguetia staudtii A flowering branch B detail of stellate pubescence on lower side of leaf blade C flower bud, side view D carpel, side view E syncarpous fruit, referred to as a pseudosyncarpous fruit F longitudinal section of fruit. Duguetia confinis G flowering branch H detail of pubescent on lower side of blade, note that it is completely covering the lower surface I flower bud, side view J detail of flower, sepals removed K outer petal, inner view L inner petals, inner view M stamen, side and front views N carpel, side and front views O longitudinal section of fruit, note completely fused monocarps P seed A–D from Letouzey 4438 E, F from Chevalier 16224 G, H from Le Testu 1774 I–N, P from Klaine 217 O from Lecompte s.n. Drawings by Hélène Lamourdedieu, Publications Scientifiques du Muséum national d’Histoire naturelle, Paris; modified from Le Thomas (1969b, pl. 18, p. 105).

Specimens examined

Central Region: Est N of Lom near Sanaga river (Yaundé) 250 km from Deng Deng, 4.84°N, 13.19°E, 01 March 1914, Mildbraed G.W.J. 8558 (K). Littoral Region: Au sud de Ngola (8 km E de l’embouchure de la Sanaga), 3.55°N, 9.698°E, 05 January 1974, Letouzey R. 12585 (P); Douala-Edea Reserve 10B, 5.01°N, 13.33°E, 01 April 1978, Thomas D.W. 1237 (K). South Region: ca 16 km from Kribi Ebolowa road Bidou plantation Kienke forReserve, 2.85°N, 10.01°E, 03 February 1969, Bos J.J. 3844 (WAG,YA); 20 km From Kribi N of Lolodorf road (SFIA logging road), 3.01°N, 10.05°E, 15 July 1969, Bos J.J. 5048 (BR,BR,K,WAG,YA); Mt Elephant ca 18 km SE of Kribi, 2.78°N, 10.5°E, 14 January 1970, Bos J.J. 6128 (BR,P,WAG); Near mouth of, 3.17°N, 9.961°E, 28 March 1928, Hédin L. 1690 (P,WAG); Campo-Ma’an area 2.71°N, 9.866°E, 26 October 2001, van Andel T.R. 4205 (KRIBI,WAG); Bipindi, 3.08°N, 10.42°E, 01 January 1904, Zenker G.A. 3195 (B,BR,E,G,L,M,MO,P,S).

Duguetia dilabens Chatrou & Repetur, Changing Genera: 69, 1998

Map 4A

Type

Gabon. Ngounié; new road from Mouila to Yeno, 5 km on either side of Kembele village, Thomas D.W. & Wilks C.M. 6510, 20 Jul 1986: lectotype, sheet here designated: WAG[WAG0143388]; isotypes: MO[MO-357359]; P[P00389133]; WAG[WAG0027128].

Description

Tree, up to 30 m tall, d.b.h. unknown; stilt roots or buttresses absent. Indumentum of stellate or fasciculate hairs; old leafless branches sparsely pubescent to glabrous, young foliate branches sparsely pubescent. Leaves: petiole 4–5 mm long, 2–3 mm in diameter, sparsely pubescent, grooved, blade inserted on the side of the petiole; blade 7–16 cm long, 2.5–6 cm wide, narrowly elliptic to narrowly obovate, apex acuminate to acute, acumen ca. 1 cm long, base acute, subcoriaceous, below sparsely pubescent when young and old, above glabrous when young and old, concolorous; midrib sunken or flat, above glabrous when young and old, below sparsely pubescent when young and old; secondary veins 8 to 15 pairs, distinct, glabrous below; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on young foliate branches, leaf opposed, not forming a peduncle. Flowers with 9 perianth parts in 3 whorls, 2 to 4 per inflorescence; pedicel 10–12 mm long, 1–2 mm in diameter, sparsely pubescent to densely pubescent; in fruit 10–50 mm long, 1–15 mm in diameter, sparsely pubescent to densely pubescent; bracts 2, one basal and one towards the lower half of pedicel, basal bracts 5–9 mm long, 7–9 mm wide; sepals 3, valvate, free, 12–15 mm long, 6–9 mm wide, elliptic to ovate, apex acute, base truncate, greyish green, pubescent outside, pubescent inside, margins flat; petals free, outer petals longer than inner to sub equal; outer petals 3, 12–15 mm long, 4–6 mm wide, ovate, apex acute, base truncate, white, margins flat, sparsely pubescent outside, glabrous inside; inner petals 3, imbricate, 13–15 mm long, 4–5 mm wide, elliptic, apex acute, base truncate, margins flat, pubescent outside, glabrous inside; stamens numerous, 1 mm long, broad; connective discoid, glabrous, red; staminodes absent; carpels free, ca. 75, 2–3.5 mm long, stigma globose, glabrous. Fruit pseudosyncarpous, size and shape unknown; carpels sessile, free to basally fused, unknown number of carpels, 20–35 mm long, ovary 10–30 mm in diameter, obovoid to deltoid, apex apiculate, pubescent, densely pubescent, longitudinally ribbed with 6 to 7 main ribs, color unknown; seed 1 per monocarp, 12–20 mm long, 10–13 mm in diameter, ellipsoid; aril present, color unknown.

Map 4. 

A Duguetia dilabens B Duguetia staudtii C Greenwayodendron glabrum D Greenwayodendron suaveolens E Hexalobus bussei F Hexalobus crispiflorus G Hexalobus monopetalus H Hexalobus salicifolius I Isolona campanulata. White borders represent region limits in Cameroon; green patches represent protected areas (see methods and Suppl. material 1: Fig. S1).

Distribution

Known from Gabon and Cameroon; in Cameroon known from South and Littoral regions.

Habitat

A rare species known from four specimens; in lowland periodically inundated or non-inundated rain forests. Altitude 0–500 m a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Endangered (EN) (Texier and Stévart 2020)

Uses in Cameroon

None recorded.

Notes

Duguetia dilabens is distinguished by its leaves that are narrowly elliptic to narrowly obovate, the midrib not grooved above and the carpels only basally fused in fruit. It was recently collected in Campo Ma’an National Park (Couvreur 692), but the sample is sterile and the identification remains doubtful, although the leaves do match the type specimen. Couvreur 692 also notes that the trunk had a bark peeling in smallish flakes.

Specimens examined

South Region: Reserve forestière de la Kienké (Kribi-Ebolowa km 16), 3.1°N, 10.25°E, 05 January 1968, Bamps P.R.J. 1679 (BR, YA); Campo Ma’an National Park 11 km on trail from Ebinanemeyong village on road 7 km from Nyabessan to Campo town, 2.49°N, 10.34°E, 12 February 2015, Couvreur T.L.P. 692 (WAG,YA).

Duguetia staudtii (Engl. & Diels) Chatrou, Changing Genera: 70, 1998

Fig. 26; Map 4B

Uvaria staudtii Engl. & Diels, Notizbl. Königl. Bot. Gart. Berlin 2: 292, 1899; Pachypodanthium staudtii Engl. & Diels, Notizbl. Königl. Bot. Gart. Berlin 3: 55, 1900.

Type

Cameroon. South Region; near Lolodorf, Staudt A. 133, 1896: holotype: B[B 10 0154084]; isotypes: BM[BM000843984]; K[K000198873, K000198874]; P[P00315814, P00315816]; S[S02-94].

Description

Tree, 15–50 m tall, d.b.h. 20–70 cm; stilt roots or buttresses absent. Indumentum of stellate or fasciculate hairs; old leafless branches sparsely pubescent to glabrous, young foliate branches sparsely pubescent to densely pubescent. Leaves: petiole 2–10 mm long, 2–4 mm in diameter, densely pubescent to sparsely pubescent, grooved, blade inserted on the side of the petiole; blade 13–34 cm long, 3–8 cm wide, narrowly obovate, narrowly oblong to narrowly elliptic, apex acuminate to acute, acumen 0.5–1 cm long, base cordate (more rarely acute), coriaceous, below sparsely pubescent when young, pubescent when old, above glabrous when young and old, concolorous; midrib sunken or flat, above glabrous when young and old, below sparsely pubescent when young and old; secondary veins 10 to 22 pairs, weakly distinct, glabrous below; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old leafless or young foliate branches, leaf opposed or extra axillary, not forming a peduncle. Flowers with 9 perianth parts in 3 whorls, 2 to 4 per inflorescence; pedicel 6–12 mm long, 2–3 mm in diameter, sparsely pubescent to densely pubescent; in fruit 2–30 mm long, 2–6 mm in diameter, sparsely pubescent to densely pubescent; bracts 2, one basal and one towards the upper half of pedicel, basal bracts 9–12 mm long, 5–7 mm wide; sepals 3, valvate, free, 9–15 mm long, 7–10 mm wide, ovate, apex acute, base truncate, green, densely pubescent outside, glabrescent inside, margins flat; petals free, outer petals longer than inner to sub equal; outer petals 3, 7–30 mm long, 4–10 mm wide, oblong-elliptic to oblong-obovate, apex acute, base truncate, cream to white, margins flat, sparsely pubescent outside, glabrous inside; inner petals 3, imbricate, 4–20 mm long, 4–6 mm wide, elliptic to obovate, apex acute to obtuse, base truncate, cream, margins flat, pubescent outside, glabrous inside; stamens 120 to 150, in 5 to 6 rows, 1–2 mm long, broad; connective discoid, glabrous, red; staminodes absent; carpels free, 50 to 100, ovary 1–1.5 mm long, stigma globose, glabrous. Fruit pseudosyncarpous, 20–55 mm in diameter, globose to depressed ovoid; carpels sessile, basally fused, 50 to 100 monocarps, 20–55 mm long, 2–10 mm in diameter, globose to ovoid, apex acute, densely pubescent, longitudinally ribbed with 5 to 6 main ribs, red when ripe; seed 1 per monocarp, 7–13 mm long, 6–8 mm in diameter, ellipsoid; aril present, pale yellow.

Distribution

A widespread species with a disjunct distribution in West (Sierra Leone, Liberia, Ivory Coast and Nigeria) and in Central Africa from Cameroon to Democratic Republic of the Congo; in Cameroon known from East, South, Central, Littoral and South-West regions.

Habitat

A common species; in lowland or premontane primary and secondary non-inundated rain forests. Altitude 100–900 m a.s.l.

Local and common names known in Cameroon

ntom (dial. Bagali); nto ntomba (dial. Bagielli) (Letouzey 1964).

IUCN conservation status

Least Concern (LC) (Cosiaux et al. 2019k).

Uses in Cameroon

medicine : bark used for pain-killers, pulmonary troubles, vermifuges, dropsy, swellings, oede gout, tumours, cancers; constructions: building materials; dyes and tannins: tannins, astringents, insecticides, arachnicides, arrow-poisons, aromatic substances, alkaloids.

Notes

Duguetia staudtii is distinguished by its narrowly obovate, narrowly oblong to narrowly elliptic leaves, the midrib that is grooved above and monocarps that are only basally fused.

Specimens examined

Central Region: Yaoundé, 3.86°N, 11.51°E, 01 January 1935, Foury P. 69 (P,WAG). East Region: 17 km along road to Deng Deng, 4.58°N, 13.68°E, 01 September 1961, Breteler F.J. 1841 (WAG); Près Kinsassa 65 km au NNE de Moloundou sur route Yokadouma 2.63°N, 15.37°E, 04 March 1971, Letouzey R. 10509 (P,YA); Colline à l’ENE de Mbalam (140 km ESE de Djoum près Souanké-Congo), 2.22°N, 13.82°E, 20 January 1973, Letouzey R. 11867 (P,YA). Littoral Region: Douala-Edéa Reserve Tissongo study area Transect B, 3.57°N, 9.869°E, 01 June 1976, Waterman P.G. 879 (U). South Region: Bitye, 3.87°N, 11.52°E, 01 January 1919, Bates G.L. 1199 (BM,MO); 17 km east from Lélé village, 2.28°N, 13.32°E, 07 September 2013, Couvreur T.L.P. 460 (WAG,YA); 25 km east from Lélé village at end of path on Ivindo river, 2.25°N, 13.28°E, 09 September 2013, Couvreur T.L.P. 489 (WAG,YA); Sud TDC, 2.65°N, 9.9°E, 06 November 1991, Hallé F. 4220 (WAG); Ncolbew 3.28°N, 11.2°E, 26 April 1928, Hédin L. 1646 (P); Colline Ebon près Nkobiyo 25 km ENE d’Ambam, 2.45°N, 11.5°E, 21 March 1970, Letouzey R. 10181 (P,YA); Mvini 35 km east of Campo, 2.37°N, 10.09°E, 20 December 1983, Mikio K. 5 (P,YA); ca 7 km NE of Ebom, 3.11°N, 10.75°E, 01 August 1996, Parren M.P.E. 157 (KRIBI,WAG); ca 7 km NE of Ebom, 3.11°N, 10.75°E, 01 August 1996, Parren M.P.E. 212 (KRIBI,WAG); Lolodorf, 3.23°N, 10.73°E, 1896, Staudt A. 133 (P); Lolodorf, 3.23°N, 10.73°E, March 1895, Staudt A. 138 (B); Campo-Ma’an area 2.4°N, 10.1°E, 02 April 2001, van Andel T.R. 3290 (KRIBI,U,WAG,YA). South-West Region: Bayang Mbo Wildlife Sanctuary after Mbu river, 5.35°N, 9.501°E, 26 March 2016, Couvreur T.L.P. 1014 (WAG,YA); Near Mamfe, 5.75°N, 9.31°E, 19 April 1978, Thomas D.W. 384 (K).

Greenwayodendron Verdc., Adansonia sér. 2, 9: 89, 1969

Thomas L.P. Couvreur

Polyalthia sect. Afropolyalthia Engler & Prantl., Leipzig, W. Engelmann.160, 1897.

Type species

Greenwayodendron suaveolens (Engl. & Diels) Verdc.

Description

Trees, 7–45 m tall, d.b.h. 3–125 cm; stilt roots or buttresses absent. Indumentum of simple hairs. Leaves: petiole 2–8 mm long, 1–3 mm in diameter, blade 6.5–16.2 cm long, 2–6.7 cm wide, elliptic to oblong, apex acuminate to caudate, base cuneate to rounded, concolorous; midrib sunken or flat; secondary veins 5 to 18 pairs; tertiary venation reticulate. Individuals androdioecious; male and bisexual inflorescences similar in appearance, ramiflorous on young foliate branches, leaf opposed or extra axillary. Flowers with 9 perianth parts in 3 whorls, 1 to 4 per inflorescence; pedicel 4–6 mm long; in fruit 6–13 mm long; bracts 2, one basal and one upper, 1–2 mm long; sepals 3, valvate, free, 2–4 mm long, ovate, apex acuminate, base truncate; petals free; outer petals longer than inner; outer petals 3, valvate, 8–18 mm long, 2.3–2.6 mm wide, oblong to elliptic, apex acuminate, base rounded; inner petals 3, valvate, 8–18 mm long, 1.3–2.6 mm wide, ovate to elliptic, apex acuminate, base rounded; stamens 15 to 25, in 4 to 5 rows, ovary 1–2 mm long, elongated; connective tongue-shaped, glabrous; staminodes absent; carpels free, 10 to 20, 1–2 mm long, stigma ovoid, pubescent. Fruits apocarpous, monocarps stipitate, stipes 5–10 mm long, monocarps 2 to 8, 8–21 mm long, 7–21 mm in diameter, ellipsoid to globose, apex rounded, smooth, green turning wine red when ripe; seed 1 to 4, 3–13 mm long, 3–13 mm in diameter, ellipsoid to flattened ellipsoid; aril absent.

A genus of six currently described species distributed across Africa. Two species are known from Cameroon, none endemic. Onana (2011) mentions Greenwayodendron oliveri (Engl.) Verdc. from Cameroon, but this is not confirmed here. The latter species is a West African endemic (Lissambou et al. 2018); several specimens from coastal Gabon previously identified as G. oliveri are now separated as a different species: G. littorale Lissambou, Dauby & Couvreur (Lissambou et al. 2018, 2019). Neither species is known from Cameroon to date.

Taxonomy

Lissambou et al. (2018).

Key to the species of Greenwayodendron in Cameroon

1 Petiole and midrib glabrous above G. glabrum
Petiole and midrib pubescent or sparsely pubescent above G. suaveolens

Greenwayodendron glabrum Lissambou, Hardy & Couvreur, PhytoKeys 114: 66, 2018

Figs 27, 29; Map 4C

Type

Cameroon. South Region; 40 km from Kribi, 5 km. E. of Edea road, tract of Fifinda-Bella road (SFIA), Bos J.J. 6267, 6 Feb 1970: holotype WAG[WAG.1433854]; isotypes BR[BR0000014826399]; YA n.v.; WAG[WAG1433855].

Description

Tree, 7–30 m tall, d.b.h. 3–20 cm; stilt roots or buttresses absent. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches pubescent. Leaves: petiole 3–6 mm long, 1–2 mm in diameter, glabrous, grooved, blade inserted on the side of the petiole; blade 6.5–16.2 cm long, 2.1–5.8 cm wide, elliptic to oblong, apex acuminate to caudate, acumen 0.4–2 cm long, base cuneate to rounded, papyraceous, below sparsely pubescent to glabrous when young, glabrous when old, above glabrous when young and old, concolorous; midrib impressed, above completely glabrous when young and old, below glabrous when young and old; secondary veins 5 to 7 pairs, glabrous below; tertiary venation indistinct. Individuals androdioecious; male and bisexual inflorescences similar, ramiflorous on old leafless and young foliate branches, leaf opposed or extra axillary. Flowers with 9 perianth parts in 3 whorls, 1 to 4 per inflorescence; pedicel ca. 4 mm long, ca. 1 mm in diameter, pubescent to glabrous; in fruit 6–13 mm long, 1–2 mm in diameter, pubescent to glabrous; bracts 2, one basal and one upper towards the upper half of pedicel, basal bracts 1–2 mm long, 2 mm wide; upper bracts 1–3 mm long, 1–3 mm wide; sepals 3, valvate, basally fused to free, 3 mm long, 3–4 mm wide, ovate, apex acuminate, base truncate, green, pubescent outside, glabrous inside, margins flat; petals free, sub equal; outer petals 3, 12–13 mm long, 2–2.5 mm wide, elliptic to ovate, apex acuminate, base rounded, green to light yellow, margins flat, pubescent outside, glabrous inside; inner petals 3, valvate, 12–13 mm long, 2–2.5 mm wide, ovate, apex acuminate, base rounded, green to light yellow, margins flat, pubescent outside, glabrous inside; stamens 10 to 15, in 4 to 5 rows, 1–2 mm long, elongated; connective tongue shaped, glabrous, green; staminodes absent; carpels free, 10 to 15, ovary ca. 1 mm long, stigma ovoid, pubescent. Monocarps stipitate, stipes 5–10 mm long, 1–3 mm in diameter; monocarps 2 to 8, 11–21 mm long, 11–21 mm in diameter, ellipsoid to globose, apex rounded, glabrous, smooth, smooth; seeds 1 to 4 per monocarp, 7–13 mm long, 7–13 mm in diameter, ellipsoid to flattened ellipsoid; aril absent.

Distribution

Known from Cameroon and Gabon; in Cameroon known from the Littoral and South regions.

Habitat

A common species when present and growing in sympatry with G. suaveolens in southern Cameroon; in lowland non-inundated primary or secondary forests. Altitude 20–750 m a.s.l.

Figure 27. 

Greenwayodendron glabrum A flowering branch B detail of lower leaf surface C detail of upper leaf surface D–G different types leaf apex H flower bud I infructescence J longitudinal section of fruit revealing seed K seed, latitudinal view L longitudinal section of seed showing ruminations A–C, G, H Letouzey 12869 D–F, I–L Bos 6267. Drawings by Hans de Vries (Lissambou et al. 2018, fig. 1, p. 63).

Local and common names known in Cameroon

None recorded, but possibly same as G. suaveolens (see below).

IUCN conservation status

Least Concern (LC) (Harvey-Brown 2019b).

Uses in Cameroon

None recorded.

Notes

This species is very close morphologically to G. suaveolens. Both species grow in sympatry in southern Cameroon. However, G. glabrum is distinguished by its glabrous petiole and upper midrib and leaf blades (versus pubescent in G. suaveolens). Studies have shown that these two species are genetically distinct at both the phylogenetic (Couvreur et al. 2019) and population genetic (Lissambou et al. 2019) levels.

Specimens examined

Central Region: Left bank Nyong R 30 km S of Edéa near bridge in road to Kribi, 3.8°N, 10.13°E, 26 April 1965, Leeuwenberg A.J.M. 5582 (B,BR,C,GC,K,LUAI,MO,P,UC,WAG,YA). Littoral Region: Ndogtima Nyong (Edéa), 3.8°N, 10.13°E, 03 February 1974, Letouzey R. 12869 (BR,P,WAG,YA). South Region: 43 kmN of Kribi 5 km E of Edea road forest track Fifinda-Bella old secondary forest, 3.21°N, 10.06°E, 06 February 1970, Bos J.J. 6267 (BR,P,WAG,YA); ca 16 km On the road from Ebolowa to Minkok, 2.98°N, 11.17°E, 12 September 1975, de Wilde J.J.F.E 8465 (B,BR,K,MO,P,WAG,YA); Mvini 35 km East of Campo, 2.39°N, 10.04°E, 19 December 1983, Kaji M. 4 (YA); Campo-Ma’an region, 2.28°N, 9.950°E, 17 January 2016, Lissambou B.J. 1745 (BRLU); Campo-Ma’an region, 2.28°N, 9.949°E, 17 January 2016, Lissambou B.J. 1748 (BRLU); Campo-Ma’an region, 2.28°N, 9.948°E, 17 January 2016, Lissambou B.J. 1775 (BRLU); Campo-Ma’an region, 2.28°N, 9.949°E, 17 January 2016, Lissambou B.J. 1788 (BRLU); Campo-Ma’an region, 2.29°N, 9.945°E, 18 January 2016, Lissambou B.J. 1807 (BRLU); Campo-Ma’an region, 2.40°N, 9.895°E, 18 January 2016, Lissambou B.J. 1828 (BRLU); Campo-Ma’an region, 2.40°N, 9.894°E, 18 January 2016, Lissambou B.J. 1830 (BRLU); Campo-Ma’an region, 3.19°N, 10.10°E, 19 January 2016, Lissambou B.J. 1855 (BRLU); Campo-Ma’an region, 3.19°N, 10.10°E, 19 January 2016, Lissambou B.J. 1856 (BRLU); Cagnon du Ntem 16 km SW de Nyabessan, 2.32°N, 10.28°E, 30 November 1982, Nkongmeneck B.A. 400 (YA).

Greenwayodendron suaveolens (Engl. & Diels) Verdc., Adansonia, n.s. 9: 90, 1969

Fig. 28, 29; Map 4D

Polyalthia suaveolens Engl. & Diels, Monogr. Afr. Pfl. 6: 42., 1901.

= Polyalthia mortehanii De Wild., Bull. Jard. Bot. État Bruxelles, 4: 384., 1914. Type. Democratic Republic of the Congo. Kasaï-Oriental: Lekimi, De Giorgi S. 1576, Dec 1913: lectotype designated by Lissambou et al. (2018), p. 77: BR[BR8804408].

= Polyalthia aubrevillei Ghesquière ex Aubréville, Fl. For. Côte d’Ivoire, i. 114, 1936. Type. Cameroon. South Region: Bipindé, Urwaldgebiet, Zenker G. 1306, 1913: lectotype designated by Lissambou et al. (2018), p. 77: P[P01985238]; isolectotypes: L[L.1761577]; MO; P[P01985239]; WAG[WAG.1379971].

= Maba gossweileri Greves., J. Bot. 67 (Suppl. 2): 76., 1929. Type. Angola. Cabinda: Buco Zau - Maiombe, Gossweiler J. 6923, 8 Jan 1917: holotype BM[BM000547162]; COI[COI00004858].

= Xylopia otunga Exell., J. Bot. 69: 99, 1931. Type. Cameroon. Central: Bitye Yaoundé, Bates G.L. 1226, 1919: holotype: BM[BM000513697]; isotype LISC[LISC000385].

Type

Gabon. Estuaire; Munda, Sibange Farm, Soyaux H. 218, 20 Feb 1881: holotype material presumably destroyed at B; lectotype, designated by Lissambou et al. 2018 (2018), p. 77: P[P00363356]; isolectotype K[K000580898].

Figure 28. 

Greenwayodendron suaveolens A flowering branch B flower bud C flower at anthesis D detail of male receptacle, petals removed E detail of hermaphrodite receptacle, petals removed F inside view of outer petal G stamen H stamen I carpel J longitudinal section of carpel K fruiting branch L lateral view of seed M seed N longitudinal section of a single monocarp showing two seeds and their ruminations A–D, F–H from Le Testu 9408; E, I, J. Gilbert 936 K–N Letouzey 5322. Drawings by Hélène Lamourdedieu, Publications Scientifiques du Muséum national d’Histoire naturelle, Paris; modified from Le Thomas (1969b, pl. 37, p. 205).

Description

Tree, 8–45 m tall, d.b.h. 10–125 cm; stilt roots or buttresses absent. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches pubescent to sparsely pubescent. Leaves: petiole 2–8 mm long, 1–3 mm in diameter, pubescent to sparsely pubescent, grooved, blade inserted on the side of the petiole; blade 5.1–15.6 cm long, 2–6.7 cm wide, elliptic to oblong, apex acuminate to caudate, acumen 0.6–1.4 cm long, base cuneate to rounded, papyraceous, below pubescent when young, glabrous to pubescent when old, above densely to sparsely pubescent when young, sparsely pubescent when old, concolorous; midrib impressed, above pubescent at least basely when young and old, below densely pubescent when young, sparsely pubescent to densely pubescent when old; secondary veins 5 to 18 pairs, glabrous below; tertiary venation indistinct. Individuals androdioecious; male and bisexual inflorescences similar, ramiflorous on old leafless and young foliate branches, leaf opposed or extra axillary. Flowers with 9 perianth parts in 3 whorls, 1 to 4 per inflorescence, pedicel 3–6 mm long, 1–2 mm in diameter, pubescent; in fruit 6–12 mm long, 2–3 mm in diameter, glabrous; bracts 2, one basal and one upper towards the upper half of pedicel, basal bracts 1–2 mm long, 2 mm wide; upper bracts 1–3 mm long, 1–3 mm wide; sepals 3, valvate, basally fused to free, 2–4 mm long, 2–4 mm wide, ovate, apex acuminate, base truncate, green, pubescent outside, glabrous inside, margins flat; petals free, sub equal; outer petals 3, 8–18 mm long, 1.3–2.6 mm wide, oblong-elliptic to ovate, apex acuminate, base rounded, green to light yellow, margins flat, pubescent outside, glabrous inside; inner petals 3, valvate, 8–18 mm long, 1.3–2.6 mm wide, elliptic to ovate, apex acuminate, base rounded, green to light yellow, margins flat, pubescent outside, glabrous inside; stamens 16 to 25, in 4 to 5 rows, 1–2 mm long, elongated; connective tongue-shaped, glabrous, green; staminodes absent; carpels free, 12 to 20, ovary 1–2 mm long, stigma ovoid, pubescent. Monocarps stipitate, stipes 5–10 mm long, 1–3 mm in diameter; monocarps 2 to 8, 8–18 mm long, 7–16 mm in diameter, ellipsoid to globose, apex rounded, glabrous, smooth, green turning wine red when ripe; seeds 1 to 4 per monocarp, 3–11 mm long, 3–11 mm in diameter, ellipsoid to flattened ellipsoid; aril absent.

Distribution

Known from Nigeria to the Republic of Congo and the Democratic Republic of Congo; in Cameroon known from the East, South, Central, Littoral and South-West regions.

Habitat

A very common species across the forest zone of Cameroon (growing in sympatry with G. glabrum in the south) with a wide ecologically amplitude; in lowland premontane, and sometimes in montane non-inundated primary or secondary forests. Altitude 20–1600 m a.s.l.

Local and common names known in Cameroon

Moabé noir (dial. Nzime), Otunga (dial. Fang), Otungui (dial. Ewondo), Ntoulen (dial. Bassa), Botounga, Botunga (dial. Baka).

IUCN conservation status

Least Concern (LC) (Harvey-Brown 2019c).

Figure 29. 

Greenwayodendron suaveolens A trunk, note light grey color B leaf, upper view C flower D flower, side view E detail of fruit, with longitudinal section of one monocarp showing 2 seeds. Greenwayodendron glabrum F branch with fruit G fruit with longitudinal section of monocarp showing seed A, E Couvreur 476, Lélé, Cameroon B Couvreur 1196, Maséa, Cameroon C, D Couvreur 560, Gabon F, G Bidault 847, Gabon. Photos A–E Thomas L.P. Couvreur F, G Ehoarn Bidault, Tropicos.org, Missouri Botanical Garden.

Uses in Cameroon

medicine : leaves as pain-killers, against arthritis, rheumatism, fabrifuges, for menstrual cycle; bark for pregnancy, antiaborifacients, root for vermifuges, as genital stimulants/depressants, dropsy, swellings, oede gout; constructions: building materials; dyes and tannins: glycosides, saponims, steroids; products: fibre wood, farming, forestry, hunting and fishing apparatus.

Notes

See under G. glabrum. The species is here treated in the narrow sense; the former varieties gabonicum Le Thomas and usambaricum Verdc. (not recorded from Cameroon) are now raised to specific rank, as G. gabonicum (Le Thomas) Lissambou & Couvreur and G. usambaricum (Verdc.) Lissambou, Hardy & Couvreur (Lissambou et al. 2019).

Selected specimens examined

Central Region: Ndanan 1, 3.62°N, 11.58°E, 21 October 2002, Cheek M. 11224 (K,YA); Mefou National Park, 3.61°N, 11.58°E, 13 March 2004, Cheek M. 27 (YA); Mefou National Park, 3.61°N, 11.58°E, 13 March 2004, Cheek M. 66 (YA); Ca 50 km S of Badjob ca 60 km SW Of Eséka Along the Njong-River, 3.68°N, 10.68°E, 19 March 1964, de Wilde W.J.J.O 2133 (B,BR,K,MO,P,WAG,YA); Yaoundé, 3.87°N, 11.52°E, 01 January 1935, Foury P. 129 (P); Ngoro, 5.06°N, 11.19°E, 29 April 2017, Kamdem N. 510 (YA); AYOS, 3.98°N, 12.36°E, 17 June 2017, Kamdem N. 560 (YA); Ossoéssam (Mbalmayo), 3.52°N, 11.5°E, 01 June 1965, Leeuwenberg A.J.M. 5755 (BR,K,P,WAG). East Region: Palisco forest consession 15 km along main road into consession, 3.48°N, 13.59°E, 27 March 2015, Couvreur T.L.P. 756 (WAG,YA); Deng Deng, 5.20°N, 13.13°E, 27 July 2014, Kamdem N. 166 (YA); Mindourou Alpicam, 4.12°N, 14.54°E, 11 December 2016, Kamdem N. 459 (YA); Colline à l’ENE de Mbalam (140 km ESE de Djoum près de Souanke-Congo, 2.22°N, 13.82°E, 20 January 1973, Letouzey R. 11866 (YA); A 6 km au Nord de Mwapak (km 43 piste Yokadouma-Lomié, 3.54°N, 14.71°E, 22 June 1963, Letouzey R. 5322 (YA). Littoral Region: Mapubi 30 km before Edea on Yaoundé-Edea road On forestry road 5 km direction to Sanaga river, 3.84°N, 10.38°E, 28 February 2018, Couvreur T.L.P. 1180 (WAG,YA); Mambe Massif above Boga village 100 km along road from Yaoundé to Ed 3.90°N, 10.77°E, 20 June 2014, Couvreur T.L.P. 658 (WAG,YA); Olombé, 3.60°N, 9.959°E, 05 November 2014, Kamdem N. 175 (YA); Chantier Bakaka km 4 Eboné-EkoMtolo road (Eboné situated on km 11 of Nkongsamba-Loum road), 4.83°N, 9.9°E, 20 August 1971, Leeuwenberg A.J.M. 8164 (BR,K,L,MO,P,U,WAG,YA). South Region: 20 km from Kribi Lolodorf road, 3.03°N, 10.05°E, 09 June 1969, Bos J.J. 4769 (B,BR,K,LD,LM,MO,P,POZG,WAG,YA); Mt Elephant ca 18 km SE of Kribi, 2.81°N, 10.01°E, 08 January 1970, Bos J.J. 6100 (BR,C,K,LD,P,WAG,YA); hill above Nlonacko near village Ebianemeyong, 2.43°N, 10.35°E, 12 December 1998, de Wilde J.J.F.E 12163 (BR,KRIBI,MO,S,WAG); 16 km on the recently reconstructed road from Ebolowa to Minkok, 2.75°N, 11.25°E, 30 January 1975, de Wilde J.J.F.E 7940 (BR,K,MO,P,U,WAG,YA); Massif de Ngovayang village de Atog Boga, 3.25°N, 10.49°E, 30 August 2015, Droissart V. 2050 (BRLU); Massif de Ngovayang village de Atog Boga, 3.25°N, 10.49°E, 05 September 2015, Droissart V. 2159 (BRLU); A 13 km au N-NW de Djoum (UFA 09-007) vers “la tache verte” Forêt dense inondée et forêt secondaire, 2.77°N, 12.74°E, 25 April 2011, Droissart V. 834 (BRLU); Ebom, 3.1°N, 10.73°E, 20 February 1996, Elad M. 443 (KRIBI,WAG); Campo, 2.28°N, 9.950°E, 05 July 2015, Kamdem N. 329 (YA); Campo, 2.39°N, 10.02°E, 07 July 2015, Kamdem N. 349 (YA); Ma’an, 2.50°N, 10.76°E, 11 July 2015, Kamdem N. 397 (YA); Essam (Nanga Eboko), 4.68°N, 12.37°E, 13 February 1959, Letouzey R. 1106 (P); Essam (Nanga Eboko), 4.68°N, 12.37°E, 13 February 1959, Letouzey R. 1313 (P); 10 km environ à l’ESE de Campo à Kribi, 2.37°N, 9.82°E, 26 March 1968, Letouzey R. 9198 (YA); Campo-Ma’an National Park, 2.38°N, 10.06°E, 01 July 2001, van Andel T.R. 3794 (KRIBI,WAG,YA); Bipindi, 3.08°N, 10.41°E, 1897, Zenker G.A. 1278 (L,P,WAG); Bipindi, 3.08°N, 10.41°E, 1899, Zenker G.A. 2062 (L,P,WAG); Bipindi, 3.08°N, 10.42°E, 01 January 1900, Zenker G.A. 2166 (L,P,WAG). South-West Region: Bayang Mbo Wildlife Sanctuary after Mbu river, 5.35°N, 9.501°E, 25 March 2016, Couvreur T.L.P. 1002 (WAG,YA); Mokoko Forest Reserve Boa/Likinge (Bousa forest), 4.42°N, 8.972°E, 05 June 1994, Ekema S.N. 1208 (K,YA); Nguti, 5.34°N, 9.496°E, 03 June 2017, Kamdem N. 537 (YA).

Hexalobus A. DC., Mém. Soc. Phys. Genève 5: 212, 1832

Thomas L.P. Couvreur

Type species

Hexalobus monopetalus (A. Rich.) Engl. & Diels.

Description

Trees, 10–40 m tall, d.b.h. 35–100 cm; stilt roots or buttresses absent, but trunk strongly fluted. Indumentum of simple hairs. Leaves: petiole 1–8 mm long, 1–4 mm in diameter; blade 3.6–36 cm long, 1.2–10 cm wide, elliptic or obovate or ovate, apex acuminate or rounded to obtuse, base cuneate or cordate, concolorous; midrib sunken or flat; secondary veins 5 to 17 pairs; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old leafless or young foliate branches, axillary. Flowers with 9 perianth parts in 2 whorls, 1 to 3 per inflorescence; pedicel (0)1–15 mm long, 1–5 mm in diameter; in fruit 2–30 mm long, 1–5 mm in diameter; bracts 5 to 6, several basal and two (sometimes fused) on upper half of pedicel; sepals 3, valvate, free, 4–21 mm long, 3–14 mm wide, ovate, apex acute, base truncate; petals 6, in a single whorl and basally fused, tube 2–10 mm long, inner and outer whorl not differentiated, equal or subequal; lobes 9–80 mm long, 3–21 mm wide, margins plicate (folded in bud) or wavy; stamens numerous, in 10 to 13 rows, 1–8 mm long, elongated; connective discoid or elongated; staminodes absent; carpels free, 2 to 16, ovary 2–5 mm long, stigma bilobed or divided into two lobes with margins coiled inwards. Fruit apocarpous, monocarps stipitate or sessile, stipes 0–3 mm long; monocarps 1 to 8, 22–95 mm long, 13–65 mm in diameter, ellipsoid to cylindrical, apex rounded, smooth or rugose or warty, pubescent, orange-brown to medium brown when ripe; seeds 2 to 36, 10–40 mm long, 7–20 mm in diameter, flattened ellipsoid; aril absent.

A genus of five species, distributed across Africa. Four species are known from Cameroon, one endemic.

This genus of trees is characterized by thin plicate (folded) petals, a unique character for Annonaceae (Botermans et al. 2011). In addition, the petals are fused at the base and form a short tube with 6 lobes, a character otherwise only seen in Isolona. The trunk of adult trees is strongly fluted, a character also seen in the larger species of the genus Isolona (e.g. I. hexaloba).

Taxonomy

Botermans et al. (2011).

Key to the species of Hexalobus in Cameroon

1 Leaf apex rounded to obtuse; pedicel 0–2 mm long, in drier regions of northern Cameroon H. monopetalus
Leaf apex acuminate; pedicel 8–25 mm long, in wetter regions of southern Cameroon 2
2 Petiole > 2.5 mm in diameter; stamens 6–8 mm long; monocarps irregularly ribbed, rugose H. bussei
Petiole < 2.5 mm in diameter; stamens > 5 mm long; monocarps not ribbed, smooth or verrucose 3
3 Leaf blade 5–10 cm long, 1.5–4 cm wide, base cuneate; corolla lobes < 30 mm long; stamens ca. 2 mm long; carpels 3–4; monocarps verrucose H. salicifolius
Leaf blade 7–25 cm long, 2.5–8.5 cm wide, base rounded to cordate or occasionally cuneate; corolla lobes > 35 mm long; stamens 3–5 mm long; carpels 7–16; monocarps smooth H. crispiflorus

Hexalobus bussei Diels, Bot. Jahrb. Syst. 39: 479, 1907

Fig. 30; Map 4E

= Hexalobus megalophyllus Engl. & Diels, Bot. Jahrb. Syst. 39: 479, 1907. Type. Cameroon. South Region, Bipindi, Zenker G.A. 2889, 1904: holotype: B[B100154197]; isotypes: BR[BR0000015306210]; COI[COI00033178]; F; G[G00011590]; HBG[HBG518920]; K[K000198935]; L[L-0049297]; M[M0089222]; MO[MO-2246481]; P[P00315838]; S[S12-22791]; US[00098767]; WAG[WAG0053629]; WRSL; WU[WU 0025867]; Z[Z-000000827].

Type

Cameroon. South Region; Kribi, Busse W.C.O. 3216, 1904: holotype: B[B 10 0154198].

Description

Tree, 20–30 m tall, d.b.h. unknown; stilt roots or buttresses absent, trunk slender, not fluted. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches pubescent. Leaves: petiole 1–7 mm long, 3–4 mm in diameter, pubescent, grooved, blade inserted on the side of the petiole; blade 15.5–36 cm long, 5.5–10 cm wide, obovate, apex acuminate, acumen 0.5–1 cm long, base cordate, coriaceous, below glabrous when young and old, above sparsely pubescent to glabrous when young, sparsely pubescent to glabrous when old, concolorous; midrib sunken or flat, above pubescent when young and old, below pubescent when young and old; secondary veins 12 to 17 pairs; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old leafless or young foliate branches, axillary. Flowers with 9 perianth parts in 2 whorls, 1 to 2 per inflorescence; pedicel 10–12 mm long, 4–5 mm in diameter, densely pubescent; in fruit 10–13 mm long, 2–3 mm in diameter, glabrous; bracts 5 to 6, several basal and two (sometimes fused) towards the upper half of pedicel, basal bracts 3–9 mm long, 2–5 mm wide; upper bracts 6–13 mm long, 2–3 mm wide; sepals 3, valvate, free, 16–20 mm long, 11–14 mm wide, ovate, apex acute, base truncate, brown, densely pubescent outside, glabrous inside, margins flat; petals basally fused, tube 2–5 mm long, purple, inner and outer whorl not differentiated, equal, lobes 23–40 mm long, 8–10 mm wide, elliptic, apex rounded, pale yellow, margins wavy, densely pubescent outside, densely pubescent inside, plicate; stamens numerous, 7–8 mm long, elongated; connective elongated, glabrous; staminodes absent; carpels free, 3 to 7, ovary 4–5 mm long, stigma elongate, pubescent. Monocarps stipitate, ca. 1 mm long, ca. 3 mm in diameter; monocarps 2 to 4, 53–78 mm long, ca. 40 mm in diameter, ellipsoid, apex rounded, sparsely pubescent, rugose, irregularly ribbed in reticulate pattern, orange when ripe; seeds 17 to 19 per monocarp, 23–28 mm long, 17–19 mm in diameter, flattened ellipsoid; aril absent.

Figure 30. 

Hexalobus bussei A flowering branch B stamen, front view. Hexalobus monopetalus C flowering branch D opened flower, one sepal and one petal removed E stamen, front view F portion of pedicel with three monocarps A, B from Zenker 3550 C–E from Letouzey 7301 F from Chevalier 305. Drawings by Hélène Lamourdedieu, Publications Scientifiques du Muséum national d’Histoire naturelle, Paris; modified from Botermans et al. (2011, fig. 3, p. 35).

Distribution

endemic to Cameroon; known from the South region.

Habitat

A rare species, in primary lowland rain forests, sometimes riverine. Altitude 0–200 m a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Endangered (EN) (Cosiaux et al. 2019l).

Uses in Cameroon

None recorded.

Notes

Hexalobus bussei is distinguished by its large leaf blades (15–36 cm long) and the irregularly ridged and strongly rugose surface of its monocarps.

Specimens examined

South Region: S bank of Kienke river just E of Kribi, 3.1°N, 10.25°E, 12 May 1969, Bos J.J. 4495 (P,WAG); 21 km from Kribi high forest exploitation N of Lolodorf road, 3.03°N, 10.05°E, 07 August 1969, Bos J.J. 5157 (BR,P,WAG,YA); ca 16 km from Kribi Lolodorf road, 3°N, 10.01°E, 19 September 1969, Bos J.J. 5370 (BR,C,K,LD,LM,MO,P,WAG,YA); Kribi, 2.95°N, 9.916°E, 01 September 1904, Busse W.C.O. 3216 (B); 31 km ESE Kribi N of Kienke River Nyabessan, 2.9°N, 10.16°E, 19 April 1968, Letouzey R. 9387 (P,YA); Bipindi, 3.08°N, 10.42°E, 01 January 1904, Zenker G.A. 2889 (B,BR,COI,F,G,L,M,MO,P,S,WAG); Bipindi, 3.08°N, 10.42°E, 26 October 1908, Zenker G.A. 3550 (BR,COI,G,M,MO,P,S); Bipindi, 3.08°N, 10.41°E, 01 January 1908, Zenker G.A. 3592 (G,K); Bipindi, 3.08°N, 10.41°E, 01 January 1909, Zenker G.A. 3889 (BR,COI,G,K,L,M,MO,P,S); Bipindi, 3.08°N, 10.42°E, 01 January 1913, Zenker G.A. 4831 (BR,G,P,S).

Hexalobus crispiflorus A. Rich., Sagra, Hist. phys. Cuba, Bot. Pl. vasc. 1: 43, 1845

Figs 31, 32; Map 4F

= Hexalobus grandiflorus Benth., Trans. Linn. Soc. London 23(3): 468, 1862. Type. Cameroon. South-West Region, “Ambas Bay”, Mann G. 709, 1861: lectotype, here designated, sheet here designated: K[K000582047]; isolectotypes: GH n.v.; K[K000105530, K000105529]; P[P00315844, P00315845].

= Hexalobus grandiflorus Benth. var. inaequilaterifolius Engl., Monogr. Afrik. Pflanzen.-Fam. 6: 57, 1901. Type. Republic of Congo: Cuvette, “Bonga, Sanga”, Schlechter F.R.R. 12685, Aug 1899: holotype: B n.v.; isotypes: BR[BR0000006915513]; WRSL n.v.

= Hexalobus lujae De Wild., Bull. Jard. Bot. État Brux. 4: 389, 1914. Type. Democratic Republic of the Congo. Kasai-Oriental, Sankuru, Luja E.P. s.n., Jun 1910: lectotype, sheet here designated: BR[BR0000008800336]; isotypes: BR[BR0000008800008, BR0000008799906].

= Hexalobus crispiflorus A.Rich. subsp. strigulosus R.E.Fr., Acta Horti Berg. 10: 71, 1930. Type. Cameroon. no location, Deistel H. 99, no date: holotype: B[B 10 0184706]; isotypes: B[B 10 0184707, B 10 0184708, B 10 0184706, B 10 0184709, B 10 0184710, B 10 0184711]; GH; M[M0089315, M0089316]; P[P00486245].

= Hexalobus mbula Exell, J. Bot. 70, suppl. Polypet.: 206, 1932. Type. Angola. Cabinda, Buco Zau, Fazenda Alsyra, Gossweiler J. 6939, 20 Jan 1917: lectotype, designated by Botermans et al. (2011), p. 41: BM n.v.; isolectotypes: COI[COI00077206]; LISC[LISC000086, LISC000089, LISC000085, LISC000088, LISC000087].

Type

Guinea. Labé; Fouta D’hiallon [Djallon], Heudelot, J. 865, Apr 1838: lectotype, sheet here designated: P[P00315839]; isotypes: P[P00315842, P00486270, P00315841]; G[G00011589].

Description

Tree, 25–40 m tall, d.b.h. up to 100 cm; stilt roots or buttresses absent, trunk deeply fluted. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches densely pubescent. Leaves: petiole 2–8 mm long, 1–3 mm in diameter, densely pubescent, grooved, blade inserted on the side of the petiole; blade 7.2–25 cm long, 2.5–8.5 cm wide, ovate to obovate, apex acuminate, acumen 0.5–1.5 cm long, base cuneate to cordate, coriaceous, below glabrous when young and old, above sparsely pubescent when young, sparsely pubescent when old, concolorous; midrib sunken or flat, above pubescent when young and old, below pubescent when young and old; secondary veins 9 to 19 pairs; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old leafless or young foliate branches, axillary. Flowers with 9 perianth parts in 2 whorls, 1 to 3 per inflorescence; pedicel 12–25 mm long, 1–2 mm in diameter, glabrous; in fruit 10–30 mm long, 4–5 mm in diameter, glabrous; bracts 5 to 6, several basal and two (sometimes fused) towards the upper half of the pedicel, basal bracts 3–9 mm long, 2–5 mm wide; upper bracts 8–12 mm long, 4–9 mm wide; sepals 3, valvate, free, 12–21 mm long, 9–12 mm wide, ovate, apex acute, base truncate, brown, densely pubescent outside, densely pubescent inside, margins flat; petals basally fused, tube 4–10 mm long, purple, inner and outer whorl not differentiated, sub equal; lobes 37–80 mm long, 6–21 mm wide, elliptic, apex rounded, green to bright yellow, margins wavy, pubescent outside, pubescent with glabrous base inside, plicate; stamens 190 to 210, in 10 to 13 rows, 3–5 mm long, elongated; connective hemispheric, glabrous, cream; staminodes absent; carpels free, 7 to 16, ovary 2–5 mm long, stigma bilobed, slightly capitate, pubescent. Monocarps stipitate, ca. 2 mm long, 2–3 mm in diameter; monocarps 1 to 8, (42)50–95 mm long, 35–65 mm in diameter, ellipsoid to oblong, apex rounded, pubescent to glabrous, smooth, not ribbed, rusty-brown; seeds 12 to 36 per monocarp, 28–40 mm long, 17–20 mm in diameter, flattened ellipsoid; aril absent.

Figure 31. 

Hexalobus crispiflorus A flowering branch B flower bud C receptacle, petals removed D stamen, front view E three carpels different views, one with longitudinal section showing ovules F pedicel with one monocarp, note smooth surface G longitudinal section of monocarp showing seeds. Hexalobus salicifolius H branch I a single detached monocarp, note verrucose surface A, C–F from Le Testu 8838 B from Le Testu 693 G, H from Chevalier 7471 I from Le Testu 6387 J from Zenker 2268. Drawings by Hélène Lamourdedieu, Publications Scientifiques du Muséum national d’Histoire naturelle, Paris; modified from Le Thomas (1969b, pl. 14, p. 85).

Figure 32. 

Hexalobus crispiflorus A base of trunk, note deep furrows B base of leaf blade, upper view C base of leaf blade, lower view D flower, side view E flower, top view F flowering branch G fruit and leaves, note smooth monocarp surface A Couvreur 506, Ottotomo, Cameroon B, C Couvreur 1197, Maséa, Cameroon D–F Couvreur 666, Ottotomo, Cameroon G Couvreur 446, Ottotomo, Cameroon. Photos Thomas L.P. Couvreur.

Distribution

A widespread species, known from Guinea-Bissau to the Democratic Republic of Congo; in Cameroon known from the East, South, Central, Littoral and South-West regions.

Habitat

A common species across the forested region of the country; in lowland or premontane periodically or non-inundated, primary or secondary rain forests, including gallery forests in savanna. Altitude 0–1000 m a.s.l.

Local and common names known in Cameroon

évota, pota (dial. Bibaya, baka), owé (dial. Ewondo, Letouzey 4433); Ow (dial. Bulu, Ndoum 129); Owoe (South Province, Mildbraed 5652); Pota (dial. Bambindjere?, Harris, Fay 516, 558, 883, 1518).

IUCN conservation status

Least Concern (LC) (Cosiaux et al. 2019m).

Uses in Cameroon

dyes and tannins : lycosides, saponims, steroids.

Uses in Cameroon

None recorded.

Notes

Hexalobus crispiflorus is morphologically close to H. salicifolius, both being tall trees with deeply fluted trunks, similar flowers and growing in similar habitats. Hexalobus crispiflorus is however distinguished by its larger leaves (7.2–25 cm versus 5–10 cm long), more numerous carpels (7 to 16 versus 2 to 4 in H. salicifolius) and smooth monocarps (versus verrucose in H. salicifolius).

Specimens examined

Central Region: Ndanan 2 to Mefou river, 3.62°N, 11.56°E, 13 October 2002, Cheek M. 11064 (K,YA); Ottotomo Forest Reserve 1 km after reserve base near small loggers road, 3.66°N, 11.28°E, 25 June 2013, Couvreur T.L.P. 446 (WAG,YA); Ottotomo Forest Reserve 3 km after reserve base near small loggers road, 3.66°N, 11.28°E, 08 September 2013, Couvreur T.L.P. 506 (WAG,YA); Ottotomo Forest Reserve 45 km South of Yaoundé 5 km on path into reserve, 3.66°N, 11.28°E, 15 January 2015, Couvreur T.L.P. 666 (WAG,YA). East Region: 73 km south of Yokadouma 30 km after Ngato 15 km after river ALPICAM ‘base de vie’ then 40 km on forestry road starting 4 km before Maséa village, 3.16°N, 14.71°E, 04 March 2019, Couvreur T.L.P. 1197 (MPU,WAG,YA); Sangha R (Ndakan), 2.78°N, 16°E, 08 March 1988, Fay J.M. 8299 (F,MO,P); West side of Sangha River, 2.35°N, 16.13°E, 01 November 1988, Harris D.J. 1518 (K,MO); West side of Sangha River, 2.35°N, 16.13°E, 02 August 1988, Harris D.J. 883 (MO,P); Rives de la Sangha près Lidjombo 120 km au N de Ouesso, 2.61°N, 16°E, 08 April 1971, Letouzey R. 10614 (P,YA); A 15 km au Sud de Djouo (20 km E de Somalomo dur le Dja), 3.32°N, 12.93°E, 25 February 1962, Letouzey R. 4433 (P,YA); South Cameroon Forest Area Molundu District Bange forest between Lokomo Bumba and Bange, 2.83°N, 15.25°E, 22 February 1911, Mildbraed G.W.J. 4539 (HBG); South Cameroon Forest Area Molundu District between Yokadouma (Post Plehn) and Assobam, 3.4°N, 14.38°E, 21 April 1911, Mildbraed G.W.J. 4996 (HBG); Réserve de Biosphère du Dja vers 500 m de la station de Bouamir, 3.19°N, 12.81°E, 27 May 2001, Senterre B. 1641 (BR); Layon nord-sud à partir de Djolimpoun (entre Somalomo-Malen), 3.33°N, 12.87°E, 13 September 1993, Sonké B. 591 (YA). Littoral Region: km 11 Loum-Solé road, 4.7°N, 9.816°E, 24 May 1972, Leeuwenberg A.J.M. 9904 (K,MO,WAG,YA). South Region: Hill roughly between Nkolandom and Nkoemvone, 2.8°N, 11.16°E, 17 January 1975, de Wilde J.J.F.E 7909 (B,BR,C,K,MO,P,U,WAG,YA); Ebolowa, 2.91°N, 11.31°E, 01 June 1911, Mildbraed G.W.J. 5652 (HBG); Ebom, 3.1°N, 10.71°E, 24 September 1996, Ndoum D. 129 (KRIBI,WAG); Kribi, 2.92°N, 9.900°E, 01 October 1997, van der Burgt X.M. 232 (KRIBI,WAG); Bisyang, 2.98°N, 9.968°E, 04 June 2006, van Velzen R. 90 (BR,G,MO,WAG). South-West Region: Melon to Nyandon ca 2 km, 4.93°N, 9.533°E, 28 November 1998, Cheek M. 9716 (K,WAG,YA); Nyasoso village on max’s trail to Mt 4.82°N, 9.701°E, 05 April 2016, Couvreur T.L.P. 1062 (WAG,YA); Ambas Bay, 4.01°N, 9.2°E, 1861, Mann G. 709 (GH,K,P).

Hexalobus monopetalus (A. Rich.) Engl. & Diels, Monogr. Afrik. Pflanzen.-Fam. 6: 56, 1901

Fig. 30; Map 4G

Uvaria monopetala A.Rich., Guill. & Perr., Fl. Seneg. tent.: 8, 1831. Hexalobus senegalensis A.DC., Mém. Soc. Phys. Genève 5: 213, 1832, superfluous name.

= Hexalobus monopetalus var. parvifolius Baker.f.; Macleod, Chiefs and cities of Central Africa: 301, 1912. Type. Central African Republic. Environs de Kaga M’bra, Chevalier A.J.B. 6486, 30 Nov 1902: holotype: K[K000582056]; isotypes: G[G00011614]; L[L0049298]; P; WAG[WAG0162940].

= Hexalobus tomentosus A.Chev., Expl. bot. Afr. occ. Énum. pl. 1: 10, 1920. Type. Mali. Ségou, Sansanding, Chevalier A.J.B. 2542, 29 Sep 1899: lectotype, designated by Botermans et al. (2011), p. 42: P[P00486157].

= Hexalobus glabrescens Hutch. & Dalziel, Fl. W. trop. Afr. 1: 52, 1927. Type. Central African Republic: Ouham, Lere to Ham, Talbot P.A. 531, 1911: lectotype, designated by Botermans et al. (2011), p. 42: K; isolectotypes: BM[BM000546380]; Z[Z-000034501].

= Hexalobus monopetalus (A. Rich.) Engl. & Diels var. obovatus Brenan, Mem. New York Bot. Gard. 8, 3: 214, 1953. Type. Zambia. North-Western, E. of Matonchi Farm, Milne-Redhead E.W.B.H. 4536, 12 Feb 1938: holotype: K[K000198933]; isotypes: BM[BM000546381]; BR[BR0000008800664]; PRE[PRE0397001-0].

= Hexalobus huillensis (Engl. & Diels) Engl. & Diels, Monogr. Afrik. Pflanzen.-Fam. 6: 56, 1901; Uvaria huillensis Engl. & Diels, Notizbl. Königl. Bot. Gart. Berlin. 2: 296, 1899. Type. Angola. Benguela, Benguella, Huilla, Antunes J.M. 266, no date: lectotype, designated by Botermans et al. (2011), p. 42: COI[COI00033141]; isolectotype: BM[BM000546379].

Type

Senegal. Tambacounda; Galam prope Bakel, Leprieur F.M.R. s.n., 1828: lectotype, designated by Botermans et al. (2011), p. 42: G[G00011597]; isolectotypes: G[G00011595, G00011593]; P[P00315834, P00315832, P00315836].

Description

Tree to shrub, 10–15 m tall, d.b.h. up to 35 cm; stilt roots or buttresses absent, often several stemmed, not fluted. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches pubescent. Leaves: petiole 1–4 mm long, 1–2 mm in diameter, densely pubescent, grooved, blade inserted on the side of the petiole; blade 3.6–17.5 cm long, 1.2–6.5 cm wide, ovate to obovate, apex rounded to obtuse, rarely acuminate, acumen 1 cm long, base cuneate to cordate, coriaceous, below pubescent when young, glabrous when old, above pubescent when young, glabrous when old, concolorous; midrib impressed, above pubescent when young, glabrous when old, below pubescent when young, glabrous when old; secondary veins 6 to 14 pairs, below; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on young foliate branches, more rarely cauliflorous, axillary. Flowers with 9 perianth parts in 2 whorls, 1 to 3 per inflorescence; pedicel sessile or short up to 2 mm long, ca. 2 mm in diameter when present, densely pubescent; in fruit 2–4 mm long, 1–2 mm in diameter, sparsely pubescent; bracts 5 to 6, several basal and two (sometimes fused) towards the upper half of pedicel, basal bracts ca. 5 mm long, ca. 4 mm wide; upper bracts ca. 5 mm long, ca. 4 mm wide; sepals 3, valvate, free, 4–7 mm long, 3–6 mm wide, ovate, apex acute, base truncate, brown, densely pubescent outside, glabrous inside, margins flat; petals basally fused, tube 3–4 mm long, inner and outer whorl not differentiated, sub equal; lobes 9–27 mm long, 3–7 mm wide, elliptic, apex rounded, cream, margins wavy, pubescent outside, pubescent inside, lobes curving inwards at the base and margins reflexed forming a hollow chamber; stamens numerous, 1–2 mm long, elongated; connective discoid, glabrous, cream-yellow; staminodes absent; carpels free, 2 to 7, ovary 2–3 mm long, stigma divided into two lobes with margins coiled inwards, pubescent. Monocarps stipitate to sessile, stipes < 3 mm long, 3–4 mm in diameter; monocarps1 to 5, 22–46 mm long, 13–22 mm in diameter, ellipsoid to cylindrical, apex rounded, sparsely pubescent, warty, constricted around the seeds, orange when ripe; seeds 2 to 8 per monocarp, 10–15 mm long, 7–10 mm in diameter, flattened ellipsoid; aril absent.

Distribution

A widespread species, known from Senegal to northern South Africa, with a disjunct population in southern Angola; in Cameroon known from the North and Far-North regions.

Habitat

A common species in drier regions of Africa; in woodland, savannas or gallery forests, on sandy soils or in rocky places. Altitude 200–1000 m a.s.l.

Local and common names known in Cameroon

Bohili (Fulfuldé) (Malzy 1954).

IUCN conservation status

Least Concern (LC) (Cosiaux et al. 2019n).

Uses in Cameroon

None recorded.

Notes

Hexalobus monopetalus is distinguished from the other Cameroonian species by being a small deciduous shrub or tree (no taller than 15 m) growing in drier areas, with sessile or subsessile flowers and small smooth monocarps (up to 46 mm long versus more than 45 mm generally).

Selected specimens examined

Far-North Region: Route Lara-Guidiguis (15 km ENE de Kaele), 10.1°N, 14.45°E, 29 August 1964, Letouzey R. 6540 (P,YA); Près Bourka (65 km SS0 de Mokolo), 10.3°N, 13.56°E, 13 October 1964, Letouzey R. 7301 (P,YA); 9 km SE Guili 10 km NE Bourrah, 10.6°N, 13.74°E, 27 November 1989, Villiers J.-F. 4713 (P,YA). North Region: Ecole de faune de Garoua, 9.3°N, 13.4°E, 09 August 2000, Dong E. 393 (YA); Sanguéré (10 km Garoua), 9.27°N, 13.47°E, 01 October 1949, Malzy P. 309 (P,YA); Environs village Boulko au pied Hossere Gode 15 km NW de Poli, 8.53°N, 13.13°E, 24 October 1983, Satabié B. 702 (P,YA); Collines de Tinguelin 10 km N de Garoua, 9.3°N, 13.4°E, 26 November 1984, Satabié B. 781 (P,YA); map # NC 33 VIII Garoua, 9.93°N, 13.86°E, 13 August 1983, Thomas D.W. 2432 (MO,P,WAG,YA).

Hexalobus salicifolius Engl., Monogr. Afrik. Pflanzen.-Fam. 6: 57, 1901

Fig. 31; Map 4H

Type

Cameroon. South Region; Bipindi, Zenker G.A. 2268, 1900: holotype: B[B 10 0154199]; isotypes: BM[BM000546383]; COI[COI00033180]; G[G00011622, G00011623]; GEOT[GOET005680]; HBG[HBG518921]; K[K000582046]; L[L 0049299]; M[M0089219]; MO n.v.; P[P00363369, P00363367]; S[S12-22767]; WAG[WAG0053744]; WU[WU0025889]; Z[Z-000034502].

Description

Tree, up to 35 m tall, d.b.h. up to 100 cm; stilt roots or buttresses absent, trunk fluted. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches densely pubescent. Leaves: petiole 1–3 mm long, 1–2 mm in diameter, sparsely pubescent, slightly grooved, blade inserted on top of the petiole; blade 5–10 cm long, 1.5–3.5 cm wide, elliptic, apex acuminate, acumen 0.5–1 cm long, base cuneate, coriaceous, above glabrous when young and old, above sparsely pubescent when young, sparsely pubescent when old, concolorous; midrib sunken or flat, below pubescent when young and old, below pubescent when young and old; secondary veins 5 to 12 pairs; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on young foliate branches, axillary. Flowers with 9 perianth parts in 3 whorls, 1 to 3 per inflorescence; pedicel 8–15 mm long, 1–2 mm in diameter, densely pubescent; in fruit 10–13 mm long, 2–3 mm in diameter, glabrous; bracts 5 to 6, several basal and two (sometimes fused) towards the upper half of pedicel, basal bracts 5 mm long, 3 mm wide; upper bracts 5 mm long, 3 mm wide; sepals 3, valvate, free, 7–11 mm long, 4–7 mm wide, ovate, apex acute, base truncate, brown, pubescent outside, densely pubescent inside, margins flat; petals basally fused, tube 2–4 mm long, purple, inner and outer whorl not differentiated, equal; lobes 17–30 mm long, 4–8 mm wide, elliptic, apex rounded, cream to yellow, margins wavy, pubescent outside, pubescent inside, plicate; stamens numerous, in 11 to 13 rows, ca. 2 mm long, elongated; connective discoid, glabrous, cream; staminodes absent; carpels free, 3 to 4, ovary 2–3 mm long, stigma divided into two lobes with margins coiled inwards, pubescent. Monocarps stipitate, 1–2 mm long, ca. 3 mm in diameter; monocarps 2 to 4, 60–93 mm long, 40–55 mm in diameter, ovoid to oblong, apex rounded, pubescent to glabrous, verrucose, rusty-brown when ripe; seeds 15 to 15 per monocarp, 22–31 mm long, 11–18 mm in diameter, flattened; aril absent.

Distribution

Known from Cameroon, Gabon and the Republic of Congo (one specimen); in Cameroon known from the East, South and Central regions.

Habitat

A fairly scarce species, in primary and secondary lowland and pre-montane rain forest, occasionally in semi-deciduous forests, in periodically inundated forests and on river banks. Altitude 50–900 m a.s.l.

Local and common names known in Cameroon

Ooué (dial. Jaundi, Hédin 1663); Owoé (dial. Yetbou, Médou 1703).

IUCN conservation status

Least Concern (LC) (Cosiaux et al. 2019o).

Uses in Cameroon

None recorded.

Notes

Hexalobus salicifolius is morphologically close to H. crispiflorus from which it is distinguished by its smaller leaves, fewer carpels (2 to 4 versus 7 to 16 in H. crispiflorus) and verrucose monocarps (versus smooth in H. crispiflorus).

Specimens examined

South Region: South Province 15 km from Kribi, 2.96°N, 9.933°E, 28 August 1970, Bos J.J. s.n. (WAG[WAG0162941]); Campakok (Camp Akok), 2.65°N, 9.9°E, 30 October 1991, Hallé F. 4181 (WAG); Colline près Mezese à 17 km ENE de Sangméli 2.95°N, 12.14°E, 19 October 1966, Letouzey R. 8122 (BR,P,YA); Bidou, 2.85°N, 9.991°E, 28 May 1954, Médou J. SRFK 1703 (P,YA); 22 km NE of Kribi Kribi-Bipindi road Bidou I cultivated fields NE of village, 3.00°N, 10.09°E, 04 June 2006, van Velzen R. 98 (WAG); 26 km N of Kribi SE of the toll post for Kribi-Edéa road forest at Bebamboue II, 3.05°N, 9.987°E, 26 May 2006, van Velzen R. 99 (WAG); Bipindi, 3.08°N, 10.42°E, 01 January 1900, Zenker G.A. 2268 (COI,G,G,K,L,M,MO,P,S,WAG); Bipindi, 3.08°N, 10.42°E, 01 January 1907, Zenker G.A. 3330 (BR,G,UPS).

Isolona Engl., Nat. Pflanzenfam. Nachtr. I: 161, 1897

Thomas L.P. Couvreur

Type species

Isolona madagascariensis (A.DC.) Engl. & Diels (a species from Madagascar).

Description

Trees, 3–30 m tall, d.b.h. 5–60 cm; stilt roots or buttresses absent. Indumentum of simple hairs or glabrous. Leaves: petiole 1–15 mm long, 1–4 mm in diameter, blade 8.5–29 cm long, 3–15 cm wide, elliptic or obovate or oblong, apex acuminate, base decurrent to rounded or acute, concolorous; midrib raised on upper surface; secondary veins 7 to 20 pairs; tertiary venation reticulate. Inflorescences ramiflorous on old leafless or young foliate branches, axillary. Flowers bisexual with 9 perianth parts in 2 whorls, 1 to 3 per inflorescence; pedicel 1–25 mm long, 1–2 mm in diameter; in fruit 2–29 mm long, 2–5 mm in diameter; bracts 2 to 7, several basal and one upper, lower half of pedicel; sepals 3, valvate, free, 1–9 mm long, 2–5 mm wide, ovate or elliptic, apex acute or acuminate or rounded, base truncate; petals 6, basally fused, tube 3–11 mm long, inner and outer whorl not differentiated, equal; lobes 6–31 mm long, 2–12 mm wide; stamens numerous, in 3 to 4 rows, 1–2 mm long, broad; connective discoid; staminodes absent; carpels fused - syncarpous, forming a single visible gynoecium, 1–3 mm long, stigma bilobed, slightly capitate or capitate. Fruit syncarpous, forming a single visible fruit, 30–90 mm long, 15–50 mm in diameter, ovoid or ellipsoid, apex apiculate or rounded or cuspidate; seeds numerous not seriate, 8–25 mm long, 5–15 mm in diameter, ellipsoid or flattened ellipsoid; aril absent.

A genus of trees with 20 known species, 15 in Africa and 5 in Madagascar. In Cameroon nine species are known, none endemic.

Isolona, together with its sister genus Monodora, are unique in Annonaceae in having truly syncarpous flowers (fused carpels) and fruits. This translates into single fruits with unordered seeds, in contrast to other genera which have either uni- or biseriate placentation. Petals in Isolona are basally fused forming a clearly visible tube, with six equal lobes of equal length in a single whorl. In the vegetative state, Isolona and Monodora (together with Polyceratocarpus pellegrinii) are characterized by a raised midrib, in contrast to a sunken or flat midrib in all other genera found in Cameroon.

Taxonomy

Couvreur (2009).

Key to the species of Isolona in Cameroon

1 Leaves and/or young foliate branches pubescent 2
Leaves and young foliate branches completely glabrous 3
2 Leaf blade inserted on top of petiole; lobes glabrous outside, pubescent inside I. congolana
Leaf blade inserted on side of petiole; lobes pubescent on both sides I. pilosa
3 Leaf blade inserted on top of petiole 4
Leaf blade inserted on sides of petiole 5
4 Flowering pedicels 14–25 mm long, corolla smooth in dried material; corolla lobes 8–15 mm long with flat margins; fruits not ribbed I. cooperi
Flowering pedicels 3–7 mm long, corolla clearly verrucose in dried material; corolla lobes 15–25 mm long with margins curving inwards; fruits ribbed longitudinally I. zenkeri
5 Sepals 4–9 mm long, papyraceous; upper bract, when present, halfway up the pedicel or subbasal, sometimes leaf-like; flowers campanulate I. campanulata
Sepals 1–3 mm long, coriaceous; upper bract absent or minute; flowers not campanulate 6
6 Base of leaf blade acute to obtuse I. hexaloba
Base of leaf blade decurrent to narrowly cuneate 7
7 Corolla lobes 4–10 times as long as wide; sepal margins glabrous I. thonneri
Corolla lobes 1.6–3.5 times as long as wide; sepal margins covered with short appressed hairs 8
8 Flowering pedicels 2–7 mm long; corolla lobes with rounded tips, narrowly elliptic to elliptic, the margins sparsely covered with short hairs I. dewevrei
Flowering pedicels 10–20 (-23) mm long; corolla lobes with acute tips, narrowly ovate to ovate, the margins glabrous I. pleurocarpa

Isolona campanulata Engl. & Diels, Monogr. Afrik. Pflanzen.-Fam. 6: 83, 1901

Fig. 33; Map 4I

= Isolona leonensis Sprague & Hutch., Bull. Misc. Inform. Kew: 151, 1916. Type. Sierra Leone. Northern Province, Yonibana, Thomas N.W. 4230, 30 Oct 1914: lectotype, designated by Couvreur (2009), p. 137: K[K000199016]. (this name was erroneously reported as “I. konensis” in Onana (2011)).

= Isolona soubreana A.Chev., Explor. Bot. Afrique Occ. Franc. 1: 12, 1920. Type. Ivory Coast. Sassandra, Chevalier A.J.B. 19088, 23 Jun 1907: lectotype, designated by Couvreur (2009), p. 137, sheet here designated: P[P00363265]; isolectotypes: P[P00363264, P00363266]; WAG[WAG0027026].

Type

Cameroon. Northern Region; Bangwe, Conrau G. 93, 17 Oct 1899: holotype: B[B 10 0154200]; isotype: K[K000198841].

Description

Tree to shrub, 10–15 m tall, d.b.h. 10–15 cm; stilt roots or buttresses absent. Indumentum absent; old leafless branches glabrous, young foliate branches glabrous. Leaves: petiole 3–6 mm long, 1–2 mm in diameter, glabrous, weakly grooved adaxially, blade inserted on the side of the petiole; blade 10–18 cm long, 3–7 cm wide, elliptic to obovate, apex acuminate, acumen 1 cm long, base decurrent to cuneate, subcoriaceous, below glabrous when young and old, above glabrous when young and old, concolorous; midrib raised, above glabrous when young and old, below glabrous when young and old; secondary veins 7 to 12 pairs, glabrous below; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old or young foliate branches, axillary. Flowers with 9 perianth parts in 2 whorls, 1 to 2 per inflorescence; pedicel 5–30 mm long, ca. 1 mm in diameter, glabrous; in fruit 2–5 mm long, 2–3 mm in diameter, glabrous; bracts 2 to 5, several basal and one upper towards the lower half of pedicel, basal bracts 2–3 mm long, 1–2 mm wide; upper bract sometimes leaf-like, 2–19 mm long, 1–4 mm wide; sepals 3, valvate, free, 4–9 mm long, 3–5 mm wide, elliptic to ovate, apex acute, base truncate, green speckled with red and purple, glabrous inside, glabrous outside, margins flat; petals basally fused, tube 4–7 mm long, inner and outer whorl not differentiated, equal; lobes 6–20 mm long, 2–7 mm wide, triangular, apex acute, green, turning bright yellow, margins flat, glabrous outside, glabrous inside, spreading horizontally; stamens numerous, in 3 to 4 rows, ca. 1 mm long, broad; connective discoid, glabrous, cream; staminodes absent; carpels fused into a single structure, ca. 2 mm long, stigma capitate, glabrous. Fruit syncarpous, sessile, 40–75 mm long, 20–35 mm in diameter, ovoid, apex rounded, glabrous, smooth, bumpy, green turning deep yellow when ripe; seeds not counted, 8–15 mm long, 5–10 mm in diameter, ellipsoid; aril absent.

Distribution

A widespread species with a disjunct distribution in West (Sierra Leone, Liberia, Ivory Coast and Ghana) and Central Africa (Cameroon, Gabon); in Cameroon known from South, Central, Littoral and South-West regions.

Habitat

An infrequent species in Cameroon; in lowland primary and secondary forests, also along rivers. Altitude 0–500 m a.s.l.

Figure 33. 

Isolona campanulata A flower, side view B flower, top view. Isolona congolana C flowering branch D base of leaf blade, top view E flower, top view F flower, bottom view G syncarpous fruit A, B no voucher, Bayang Mbo, Cameroon C–G Couvreur 1054, Mt Cameroon. Photos A, B Sonneck C–G Thomas L.P. Couvreur .

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Least Concern (LC) (Cosiaux et al. 2019p).

Uses in Cameroon

medicine : root against rheumatism, allay fever.

Notes

This species is characterized by its large, foliaceous, and glabrous sepals, not appressed against the corolla tube, as well as the sometimes leaf-like upper bract. It is also a completely glabrous species, a character only shared with I. cooperi and I. hexaloba. The flower of I. campanulata is very distinct and uniquely campanulate.

Specimens examined

Littoral Region: Lombe amp Tissongo Study Area Doula-Edea Reserve, 3.78°N, 10.04°E, 01 June 1976, Waterman P.G. 830 (K). South Region: ca 15 km SE of Kribi Kienke Forest Res at Bidou II, 2.86°N, 10.03°E, 30 June 1969, Bos J.J. 4947 (BR,P,WAG,YA); 10 km From Kribi Lolodorf road, 2.96°N, 9.966°E, 09 July 1970, Bos J.J. 7069 (WAG). South-West Region: 5.46°N, 9.883°E, 7 October 1899, Conrau G. 93 (B,K); 16 minutes from research station towards rivers, 5.34°N, 9.496°E, 27 November 2000, Gosline W.G. 289 (K); Ente Ekondo Nene et Loe 15 km NW Ekondo Titi, 4.69°N, 8.97°E, 03 June 1976, Letouzey R. 15078 (P,YA); Korup National Park, 5.31°N, 8.966°E, 02 July 1951, Olorunfemi J. 30662 (K); Korup National Park between the Ndian River at PAMOL field and 25 km on transect “ P ”, 5.01°N, 8.833°E, 12 April 1985, Thomas D.W. 4763 (BR,K,MO,P,WAG,YA); Takamanda Forest Reserve, 6.21°N, 9.433°E, 30 April 1987, Thomas D.W. 7354 (MO,P,WAG).

Isolona congolana (De Wild. & T. Durand) Engl. & Diels, Monogr. Afrik. Pflanzen.-Fam. 6: 84, 1901

Figs 33, 34; Map 5A

Monodora congolana De Wild. & T. Durand, Bull. Soc. Roy. Bot. Belgique 38: 13, 1899.

= Isolona maitlandii Keay, Kew Bull. 7(2): 155, 1952. Type. Cameroon. North-West Province, Ngong, Maitland T.D. 1555, Jun 1931: holotype: K[K000105576]; isotypes: BM, FHO.

Type

Democratic Republic of the Congo. Equateur; Lukandu, Dewèvre A.P. 1103, 19 Nov 1896: lectotype, sheet here designated: BR[BR0000006248932]; isotypes: BR[BR0000006248857, BR0000006249588, BR0000006249250].

Description

Tree, 10–30 m tall, d.b.h. 5–45 cm; stilt roots or buttresses absent. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches densely pubescent. Leaves: petiole 4–7 mm long, 2–3 mm in diameter, densely pubescent, grooved, blade inserted on top of the petiole; blade 13–19 cm long, 4–5 cm wide, narrowly ovate to narrowly elliptic or oblong, apex acuminate, acumen 0.5–1 cm long, base cuneate to rounded, subcoriaceous, below sparsely pubescent when young, glabrous when old, above sparsely pubescent when young, glabrous when old, concolorous; midrib raised, above sparsely pubescent when young, glabrous when old, below sparsely pubescent when young, glabrous when old; secondary veins 11 to 14 pairs, sparsely pubescent to glabrous below; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old leafless or young foliate branches, axillary. Flowers with 9 perianth parts in 2 whorls, 1 to 3 per inflorescence; pedicel 10–23 mm long, 1 mm in diameter, sparsely pubescent to glabrous; in fruit 2–5 mm long, 2–3 mm in diameter, glabrous; bracts 3 to 4, several basal and one upper towards the lower half of pedicel, basal bracts 1 mm long, 1 mm wide; upper bracts 1 mm long, 1 mm wide; sepals 3, valvate, free, 3 mm long, 2 mm wide, ovate, apex acute, base truncate, green, pubescent outside, glabrous inside, margins flat; petals basally fused, tube 4–10 mm long, inner and outer whorl not differentiated, equal; lobes 9–20 mm long, 3–7 mm wide, elliptic to ovate, apex rounded, green turning red, margins wavy, glabrous outside, densely pubescent inside, spreading horizontally; stamens numerous, in 3 to 4 rows, 2 mm long, broad; connective discoid, densely pubescent, cream; staminodes absent; carpels fused into a single structure, 2 mm long, stigma bilobed, slightly capitate, densely pubescent. Fruit syncarpous, sessile, 60–80 mm long, 40–50 mm in diameter, ellipsoid, apex rounded, glabrous, smooth to verrucose, irregularly ribbed, green when ripe; seeds not counted, 15–25 mm long, 10–15 mm in diameter, ellipsoid; aril absent.

Figure 34. 

Isolona congolana A flowering branch B Flowers C young flower bud D flower E transversal section of flower showing receptacle, stigma and stamens F stamen G fruit A, C–F Leeuwenberg 9550 B Wesphal 10012 G Richardson 234. Drawings by Hans de Vries (Couvreur 2009, fig. 19, p. 39).

Map 5. 

A Isolona congolana B Isolona cooperi C Isolona dewevrei D Isolona hexaloba E Isolona pilosa F Isolona pleurocarpa G Isolona thonneri H Isolona zenkeri I Letestudoxa bella. White borders represent region limits in Cameroon; green patches represent protected areas (see methods and Suppl. material 1: Fig. S1).

Distribution

A central African species, with a disjunct distribution between the Cameroon Volcanic Line in Cameroon, and Eastern Democratic Republic of Congo, one collection from Central African Republic; in Cameroon known from the Littoral, North-West and South-West regions.

Habitat

A common species when present, mainly in montane or premontane rain forests, along rivers and bush land. Altitude 800–1700 m a.s.l.

Local and common names known in Cameroon

Ndin (Westphal 10012).

IUCN conservation status

Least Concern (LC) (Cosiaux et al. 2019q).

Uses in Cameroon

food : fruit for condiments, spices, flavourings (Westphal 10012).

Notes

This the only species of Isolona growing above 1000 m in Cameroon. Isolona congolana is characterized by the densely pubescent inner part of the corolla tube and a glabrous outer part of the tube, a unique feature in this genus (I. pilosa is pubescent on both sides of the corolla). The leaves are also characteristic being narrowly ovate to narrowly elliptic or oblong, giving a unique aspect to the foliage.

Specimens examined

Littoral Region: Manengouba Mt 4 km WNW Of Nkongsamba, 4.98°N, 9.900°E, 04 April 1972, Leeuwenberg A.J.M. 9550 (B,BR,C,GC,H,K,LD,M,MO,P,WAG,YA). North-West Region: Kagwene, 6.12°N, 9.734°E, 20 May 2009, Ashworth J. 196 (K,YA); Bamenda Distr Ngong, 6.58°N, 10.43°E, 01 June 1931, Maitland T.D. 1555 (BM,K); Bamenda Wae, 6°N, 10.41°E, 01 April 1931, Maitland T.D. 1596 (K). South-West Region: Nyasoso, 4.86°N, 9.7°E, 04 June 1996, Cable S. 2843 (K,MO,WAG,YA); 2 km north of Nyasoso towards Mpako, 4.84°N, 9.679°E, 04 April 2016, Couvreur T.L.P. 1054 (WAG,YA); Nyasoso, 4.83°N, 9.683°E, 19 March 1996, Etuge M. 1794 (K,WAG); White trail (above Kupe village) towards Madam 4.78°N, 9.716°E, 28 May 1996, Etuge M. 2000 (BR,K,MO,P,WAG,YA); Lake Edip, 4.95°N, 9.65°E, 21 November 1998, Etuge M. 4488 (K,WAG,YA); Etube Tape from Nyasoso, 4.83°N, 9.683°E, 06 February 1995, Lane P. 532 (K,YA); Bu 4.15°N, 9.233°E, 6 June 1898, Lehmbach H. 224 (B) . West Region: Bali Ngemba Forest Reserve, 5.82°N, 10.08°E, 13 April 2004, Etuge M. 5431 (K,WAG,YA); Along the road 6 km W of Dschang on road to Fongo Ndeng, 5.45°N, 9.95°E, 15 May 1978, Westphal E. 10012 (P,WAG).

Isolona cooperi Hutch. & Dalziel ex G.P.Cooper & Record, Bull. Yale Univ. School For. No. 31: 15, 1931

Fig. 35; Map 5B

Type

Liberia. Montserrado; near Firestone plantations, along Dukwai road, Cooper G.P. 417, 7 May 1929: lectotype, designated by Couvreur (2009), p. 148: GH[GH00286760]; isotypes: F[F0093217]; FHO[FHA00095994]; G[GH00286760]; K n.v.; NY[NY00026103]; WIS[WIS00000299MAD].

Description

Tree, 6–18 m tall, d.b.h. 20 cm; stilt roots or buttresses absent. Indumentum absent; old leafless branches glabrous, young foliate branches glabrous. Leaves: petiole 1–5 mm long, 2–3 mm in diameter, glabrous, grooved, blade inserted on top of the petiole; blade 15–29 cm long, 6–15 cm wide, oblong to obovate, apex acuminate, acumen 1–2 cm long, base cuneate to rounded, subcoriaceous, below glabrous when young and old, above glabrous when young and old, concolorous; midrib raised, above glabrous when young and old, below glabrous when young and old; secondary veins 9 to 18 pairs, glabrous below; tertiary venation reticulate. Individuals bisexual; inflorescences cauliflorous or ramiflorous on young foliate branches, axillary. Flowers with 9 perianth parts in 2 whorls, 1 to 2 per inflorescence; pedicel 14–25 mm long, 1 mm in diameter, glabrous; in fruit 16–27 mm long, 2 mm in diameter, glabrous; bracts 2 to 4, all basal, 1 mm long, 1mm wide; sepals 3, valvate, free, 2 mm long, 2 mm wide, ovate, apex rounded, base truncate, green, glabrous outside, glabrous inside, margins flat; petals basally fused, tube 6–11 mm long, inner and outer whorl not differentiated, equal; lobes 8–15 mm long, 4–6 mm wide, oblong, apex acute to rounded, green, margins flat, glabrous outside, glabrous inside, spreading horizontally; stamens numerous, in 3 to 4 rows, 2 mm long, broad; connective discoid, glabrous, green; staminodes absent; carpels fused into a single structure, 3 mm long, stigma capitate, glabrous. Fruit syncarpous, sessile, 30–90 mm long, 15–30 mm in diameter, ellipsoid, apex apiculate, glabrous, smooth, constricted over seeds in dried material, smooth when fresh, orange with white spots when ripe; seeds not counted, 10–15 mm long, 5–10 mm in diameter, ellipsoid; aril absent.

Distribution

A mainly West African species, from Liberia to Ghana, with a few specimens from Cameroon and one from Gabon; in Cameroon known from South and South-West regions.

Habitat

A rare species in Cameroon; in lowland primary and secondary forests, also along rivers, on sandy soils. Altitude 0–300 m a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Least Concern (LC) (Cosiaux et al. 2019r).

Uses in Cameroon

None reported.

Notes

Isolona cooperi is distinguished by its completely glabrous leaves, young foliate branches and flowers and with the leaf blade inserted on top of the petiole. In addition, the flowers emit a very strong sweet scent, noticeable even in dried material. It has a smooth corolla in dried material and corolla lobes with straight margins. Isolona cooperi is similar to I. hexaloba by the shape of its flowers, but the latter differs by its blade inserted sideways to the petiole and the absence of the strong sweet scent. Finally, I. cooperi resembles I. campanulata by the shape of the fruits.

Figure 35. 

Isolona cooperi A flowering branch B leaf, lower view C detail of petiole and axillary inflorescence D flower bud E flower, side view F flower, semi side view G flower, bottom view H transversal section showing androecium and stigma I stamen, front view J fruit (dried) K fruit, part of pericarp removed showing ruminate section of seed (fresh) L seed with seed coat partially removed showing ruminations A–C from J.J.F.E. de Wilde 3644 D–I from fresh material collected at the Utrecht University Botanical Garden J, L from de Koning 149 K from Breteler 7458. Drawings Hans by Vries (Couvreur 2009, fig. 21, p. 42).

Specimens examined

South Region: Bipindi, 3.08°N, 10.41°E, 01 February 1910, Zenker G.A. s.n. (F). South-West Region: Korup National Park, 5.06°N, 8.855°E, 10 March 1998, Kenfack D. 1063 (MO,WAG).

Isolona dewevrei (De Wild. & T. Durand) Engl. & Diels, Monogr. Afrik. Pflanzen.-Fam. 6: 83, 1901

Fig. 36; Map 5C

Monodora dewevrei De Wild. & T. Durand, Bull. Soc. Roy. Bot. Belg., Compt. Rend. 38: 11, 1899.

Type

Democratic Republic of the Congo. Bas Congo; Lemba-Luki, Dewèvre A.P. 365, no date: lectotype, sheet here designated: BR[BR0000008801050]; isotypes: BR[BR0000008799968, BR0000008800725, BR0000008799630].

Description

Tree to shrub, 8–15 m tall, d.b.h. 20 cm; stilt roots or buttresses absent. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches glabrous. Leaves: petiole 4–15 mm long, 1–2 mm in diameter, glabrous, grooved, blade inserted on the side of the petiole; blade 10–17 cm long, 4–7 cm wide, elliptic to obovate, apex acuminate, acumen ca. 1 cm long, base decurrent to cuneate, papyraceous, below glabrous when young and old, above glabrous when young and old, concolorous; midrib raised, above glabrous when young and old, below glabrous when young and old; secondary veins 9 to 14 pairs, glabrous below; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old branches, axillary. Flowers with 9 perianth parts in 2 whorls, 1 per inflorescence; pedicel 2–7 mm long, 1 mm in diameter, sparsely pubescent; in fruit 9–10 mm long, 2–3 mm in diameter, glabrous; bracts 3 to 5, several basal and one upper towards the lower half of pedicel, basal bracts 1 mm long, 0.5–1 mm wide; upper bract 1 mm long, 1 mm wide; sepals 3, valvate, free, 2–3 mm long, 3–4 mm wide, ovate, apex acuminate, base truncate, glabrous outside, glabrous inside, margins flat; petals basally fused, tube 3–4 mm long, inner and outer whorl not differentiated, equal; lobes 7–17 mm long, 5–7 mm wide, elliptic, apex rounded, green, margins flat, overall glabrous but pubescent towards margins outside and inside; margins curved outwards; stamens ca. 50, in 3 to 4 rows, 2 mm long, broad; connective discoid, glabrous; staminodes absent; carpels fused into a single structure, ca. 1 mm long, stigma capitate, glabrous. Fruit syncarpous, sessile, 60–70 mm long, 40–50 mm in diameter, ovoid, apex rounded, glabrous, smooth, not ribbed, green when ripe; seeds not counted, 10–20 mm long, 10–15 mm in diameter, ellipsoid; aril absent.

Distribution

A widespread species, but with few overall specimens, from Liberia to Nigeria, and from Cameroon to Democratic Republic of Congo; in Cameroon in the South and South-West regions.

Figure 36. 

Isolona dewevrei A flowering branch B flower (side view) C flower top view D transversal section of flower E detail of stig top view F transversal section of seed G fruit (left) and longitudinal section of fruit (right) H seed, side view (top), detail of hilum (bottom). Modified from Aké Assi (1963, fig. 1, p. 14).

Habitat

A rare species in Cameroon known from two specimens; in lowland primary and secondary forests. Altitude 0–860 m a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Least Concern (LC) (Cosiaux et al. 2019s).

Uses in Cameroon

None reported.

Notes

Isolona dewevrei resembles I. thonneri in leaf and fruit shape, but the former can be distinguished by its elliptic and shorter corolla lobes with hairy margins and its flowering pedicel sparsely covered with short hairs. It is, however, very hard to distinguish both species apart based on fruit or vegetative characters alone.

Specimens examined

South Region: Ngongondje hill near Akonetye 2 30'S of Ebolowa, 2.5°N, 11.13°E, 28 August 1979, Koufani A. 123 (P,YA). South-West Region: Piste Munkep-Gayama 40 km NNW Wum, 6.73°N, 9.95°E, 08 July 1975, Letouzey R. 13984 (K,MO,YA).

Isolona hexaloba (Pierre) Engler, Nat. Pflanzenfam. Nachtr. zu 3(2): 161, 1897

Figs 37, 38; Map 5D

≡ Monodora hexaloba Pierre, Fig. Herb. L. Pierre, del. E. Delpy 5/1896, 1896.

= Isolona bruneelii De Wild., Ann. Mus. Congo Belge, Bot. ser. 5, 3(1): 82, 1909. Type. Democratic Republic of the Congo. Orientale, Dikila, Bruneel A.C.E. s.n., Dec 1906: lectotype, sheet here designated: BR[BR0000008800152] ; isotypes: BR[BR0000008799692, BR0000008799364, BR0000008799302]; S[S10-20956].

= Isolona seretii De Wild., Ann. Mus. Congo Belge, Bot. ser. 5, 3[1]: 82, 1909. Type. Democratic Republic of the Congo. Equateur, near Nala, Seret F. 792, Mar 1907: lectotype, sheet here designated: BR[BR0000008800992]; isotype: BR[BR0000008801326].

= Isolona solheidii De Wild., Ann. Mus. Congo Belge, Bot. sér. 5, 3: 83, 1909. Type. Democratic Republic of the Congo. Equateur, surroundings of Yambuya, Solheid A.F. s.n., 1906: lectotype, sheet here designated: BR[BR0000008799395]; isotype: BR[BR0000008799722].

= Isolona seretii var. grandifolia De Wild., Ét. Fl. Bang. Ub.: 313, 1911. Type. Democratic Republic of the Congo. Orientale, Mobwasa, Claessens J. 615, Apr 1910: holotype: BR.

= Isolona pleurocarpa subsp. nigerica Keay, Kew Bull. 7: 157, 1952. Type. Nigeria. Ijebu State, Shasha Forest Reserve, Richards P.W. 3343, 8 Apr 1935: holotype: BM[BM000546386]; isotypes: BR[BR0000014130090]; G[G00011543, G00011544]; MO[MO-2246487]; S[S10-20983].

Type

Gabon. Estuaire; Environs de Libreville, Klaine T.-J. 360, 17 Feb 1896: lectotype, sheet here designated: P[P00363270]; isotypes: B; K[K00198842]; P[P00363269, P00363268]; WAG[WAG0251603].

Description

Tree to shrub, 15–30 m tall, d.b.h. up to 50 cm; stilt roots or buttresses absent, trunk deeply fluted. Indumentum absent; old leafless branches glabrous, young foliate branches glabrous. Leaves: petiole 2–4 mm long, 2–3 mm in diameter, glabrous, grooved, blade inserted on the side of the petiole; blade 10–28 cm long, 3–11 cm wide, ovate to elliptic, apex acuminate, acumen 1–2 cm long, base obtuse to acute, coriaceous, below glabrous when young and old, above glabrous when young and old, concolorous; midrib raised, above glabrous when young and old, below glabrous when young and old; secondary veins 8 to 16 pairs, glabrous below; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old or young foliate branches, axillary. Flowers with 9 perianth parts in 2 whorls, 1 to 2 per inflorescence; pedicel 7–30 mm long, ca. 1 mm in diameter, glabrous; in fruit 20–29 mm long, 3–5 mm in diameter, glabrous; bracts 3 to 5, several basal and one upper towards the lower half of pedicel, basal bracts ca. 1 mm long, 0.5 mm wide; upper bract 2–5 mm long, ca. 1 mm wide; sepals 3, valvate, free, 1–3 mm long, 2–4 mm wide, elliptic, apex acuminate, base truncate, green, glabrous outside, glabrous inside, margins flat; petals basally fused, tube 4–10 mm long, inner and outer whorl not differentiated, equal; lobes 6–25 mm long, 4–12 mm wide, elliptic to ovate, apex acute to rounded, dark red, margins flat to wavy, glabrous outside, glabrous inside, spreading horizontally; stamens numerous, in 3 to 4 rows, 2 mm long, broad; connective discoid, glabrous, green; staminodes absent; carpels fused into a single structure, ca. 1 mm long, stigma bilobed, slightly capitate, glabrous. Fruit syncarpous, sessile, 30–70 mm long, 25–40 mm in diameter, ovoid, apex rounded, glabrous, smooth, bumpy, irregularly and transversely ribbed, light green to dark purple when ripe; seeds not counted, 8–15 mm long, 4–6 mm in diameter, ellipsoid; aril absent.

Distribution

A widespread species from Nigeria to the Democratic Republic of Congo and northern Angola (one specimen); in Cameroon known from Adamaoua, East, South, Central, Littoral and South-West, North-West regions.

Habitat

A relatively rare species in Cameroon; in lowland primary and secondary evergreen forests, but also in semi-deciduous forests, also along rivers. Altitude 0–700 m a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Least Concern (LC) (Cosiaux et al. 2019t).

Uses in Cameroon

None reported.

Notes

Isolona hexaloba is distinguished by the short and grooved petiole with the leaf blade inserted on its sides. The corolla lobes are coriaceous and can be quite variable in shape, ranging from elliptic to obovate, with a narrowed base. It is a polymorphic species and has been described under several names, now all reduced to synonymy (Couvreur 2009). Isolona hexaloba resembles I. cooperi by the shape of the corolla lobes, but is distinguished by the insertion of the leaf blade on the side a short petiole and lacks the strong sweet smell. Isolona hexaloba is also similar to I. pleurocarpa, but the later can be distinguished by its decurrent to narrowly cuneate leaf bases, longer petioles, and papyraceous corolla lobes.

Specimens examined

Central Region: Tibati près Mbatimbang, 6.14°N, 12.48°E, 04 December 1959, Letouzey R. 2392 (P,YA). East Region: A 25 km environ à l’ENE de Mikel village situé à 85 km au N de Moloundou sur la route de Yokadouma 2.93°N, 15.33°E, 24 February 1971, Letouzey R. 10419 (P,WAG,YA); A 14 km à l’Ouest de Yenga Port Gentil village situé à 35 km au NNE de Moloundou, 2.35°N, 15.35°E, 21 April 1971, Letouzey R. 10703 (BR,COI,K,P,WAG,YA); A 20 km au Sud de Mboy I (45 km à l’Est de Yokadouma), 3.38°N, 15.13°E, 16 May 1963, Letouzey R. 5072 (K,P,WAG,YA). Littoral Region: Douala (route Razel), 4.05°N, 9.71°E, 01 January 1955, Endengle E. SRFK 2121 (P,YA); Roue forestière SNCB (km 36 vers Ndoksom) environ 25 km Sud Yabassi, 4.31°N, 9.958°E, 11 May 1976, Letouzey R. 14910 (C,K,MO,P,WAG,YA); Tissongo, 3.58°N, 9.9°E, 01 August 1976, McKey D.B. 245 (K). South Region: ca 15 km east from Lélé village, 2.28°N, 13.32°E, 10 September 2013, Couvreur T.L.P. 495 (WAG,YA); near Bipaga II km 40 road Kribi-Edéa, 3.15°N, 10.01°E, 30 December 1982, de Kruif A.P.M. 998 (MO,WAG,YA); 17 km S of the Lobe river along the road to Campo, 2.81°N, 10.13°E, 18 March 1975, de Wilde J.J.F.E 8088 (BR,K,MO,P,U,WAG,YA); A l’Ouest d’Alati (100 km SE de Djoum), 2.2°N, 13.42°E, 13 January 1973, Letouzey R. 11840 (K,P,YA); 22 km on road Kribi to Campo 12 km past Gross Batanga, 2.76°N, 9.881°E, 24 February 1994, Wieringa J.J. 2327 (MPU,U,WAG); Bipindi, 3.08°N, 10.41°E, 01 November 1901, Zenker G.A. s.n. (P). South-West Region: Korup National Park, 5.01°N, 8.783°E, 31 October 2005, van der Burgt X.M. 791 (BR,G,K,MO,P,WAG,YA). West Region: Bali- Ngemba FR, 5.81°N, 10.08°E, 13 April 2002, Onana J.M. 2030 (K,WAG).

Figure 37. 

Isolona hexaloba A, B flowering branch C transversal section of flower showing androecium and stigma D flower (bottom view) E stamens inner row (2 top); stamens of inner most row (top) and outermost row (bottom) F carpel and detail of ovules G fruits, the one on the right opened to show seeds H seed (left) and transversal section of seed showing ruminate endosperm (right) A, C–F from Le Testu 5862 B Le Testu 5836 G, H Klaine 360. Drawings by Hélène Lamourdedieu, Publications Scientifiques du Muséum national d’Histoire naturelle, Paris; modified from Le Thomas (1969b, pl. 66, p. 357).

Figure 38. 

Isolona hexaloba A trunk, note deeply furrowed B base of leaf blade, note raise midrib C flower, top view D flower, side view E fruiting branch. Isolona pleurocarpa F trunk G bade of leaf blade, notice decurrent base H flower, top view, fallen on ground I syncarpous fruit; fallen on ground A Sosef 2032, Gabon B–D Couvreur 561, Gabon E Texier 2347, Gabon F–I Couvreur 402, Ngovayang, Cameroon. Photos A–D, F–I Thomas L.P. Couvreur E Nicolas Texier, Tropicos.org, Missouri Botanical Garden.

Isolona pilosa Diels, Bot. Jahrb. Syst. 41: 328, 1908

Fig. 39; Map 5E

= Isolona theobromina Exell, J. Bot. 64 (Suppl. 1): 10, 1926. Type. Angola. Cabinda, Pango Munga, Gossweiler J. 6112, 7 Jan 1916: holotype: BM[BM000889332]; isotypes: COI[COI00077211]; LISJC n.v.; LISC[LISC000094, LISC000095, LISC000096].

Type

Democratic Republic of the Congo. Kasai Oriental; Lualaba, Ledermann C. 11, Mar 1906: holotype: B[B 10 0154216]; isotype: K n.v.

Description

Tree, 13 m tall, d.b.h. up to 50 cm; stilt roots or buttresses absent, trunk not fluted. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches densely pubescent. Leaves: petiole 3–12 mm long, 3–4 mm in diameter, densely pubescent, grooved, blade inserted on the side of the petiole; blade 19–27 cm long, 6–10 cm wide, obovate, apex acuminate, acumen 1–2 cm long, base rounded to cordate, papyraceous, below densely pubescent when young, densely pubescent when old, above sparsely pubescent to glabrous when young, sparsely pubescent to glabrous when old, concolorous; midrib raised above, above sparsely pubescent when young, sparsely pubescent when old, below densely pubescent when young, densely pubescent when old; secondary veins 15 to 20 pairs, glabrous below; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old branches, axillary. Flowers with 9 perianth parts in 2 whorls, 1 to 2 per inflorescence; pedicel 2–4 mm long, 1–2 mm in diameter, densely pubescent; in fruit 2–8 mm long, 2–3 mm in diameter, pubescent; bracts 2 to 4, all basal, 2–4 mm long, 1–2 mm wide; sepals 3, valvate, free, 2–5 mm long, 2–4 mm wide, ovate, apex acuminate, base truncate, densely pubescent outside, glabrous inside, margins flat; petals basally fused, tube 5–10 mm long, inner and outer whorl not differentiated, equal; lobes 8–13 mm long, 3–5 mm wide, elliptic, apex acute, yellow, margins flat, densely pubescent outside, pubescent with base glabrous inside, curving inwards over the receptacle; stamens numerous, in 3 to 4 rows, 2 mm long, broad; connective discoid, glabrous; staminodes absent; carpels fused into a single structure, 2 mm long, stigma bilobed, glabrous. Fruit syncarpous, sessile, 30–60 mm long, 20–40 mm in diameter, ellipsoid, apex cuspidate, sparsely pubescent, longitudinally ribbed, color unknown; seeds not counted, 13–15 mm long, 6–8 mm in diameter, flattened ellipsoid; aril absent.

Figure 39. 

Isolona letestui (not in Cameroon) A flowering branch B opened flower showing androecium and stigma C carpel (left) and transversal section of carpel (right) D stamens of innermost row (2 top) and stamen of outermost row (bottom). Isolona pilosa E flowering branch F opened flower showing androecium and stigma G stamen of outermost row (left) and innermost row (right) A–D from Le Testu 1252; E from Le Testu 8740 F, G from Le Testu 8602. Drawings by Hélène Lamourdedieu, Publications Scientifiques du Muséum national d’Histoire naturelle, Paris; modified from Le Thomas (1969b, pl. 65, p. 351).

Distribution

A central African species with a disjunct distribution, from Cameroon to Gabon and the Republic of Congo, also present in the Democratic Republic of Congo; in Cameroon known from the extreme East region.

Habitat

A rare species in Cameroon; in lowland rain forests or swampy areas. Altitude 100–450 m a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Vulnerable B2ab(iii) (Cosiaux et al. 2019u).

Uses in Cameroon

None reported.

Notes

Isolona pilosa is the most pubescent species of the genus. It is distinguishable by its densely pubescent leaf midrib on the upper side (even in older leaves), as well as its short and densely hairy flowering pedicels. The corolla lobes are densely hairy on the outside and near the margins on the inside; the inner part of the tube is glabrous, which distinguishes it from I. congolona which is pubescent on the inner surface of the tube but glabrous on the outside.

Several specimens collected by Harris DJ are reported from The Lobéké National Park in East Cameroon, but we were not able to see them and verify their identification (e.g. 6408, 6538, 6627).

Specimens examined

East Region: Region near Station Molundu Dscha (Ngoko) Nginda 21 km north Molundu, 2.2°N, 15.2°E, 07 January 1911, Mildbraed G.W.J. 4193 (HBG).

Isolona pleurocarpa Diels, Bot. Jahrb. Syst. 39: 485, 1907

Fig. 38; Map 5F

= Isolona leucantha Diels, Bot. Jahrb. Syst. 39: 484, 1907. Type. Cameroon. South Region, Bipindi, Zenker G.A. 3038, Apr 1904: holotype: B[B 10 0154212]; isotypes: BM[BM000546385]; BR[BR0000008802644]; COI[COI00077204]; E[E00259306]; G[G00011566]; GOET[GOET005681]; HBG[HBG518922]; K[K000199011]; L[L-0182762]; M[M0089224]; MO[M0089224]; P[P00363267]; S[S-G-7462]; WAG[WAG0000090]; WU[WU0025864].

Type

Cameroon. South Region; Bipindi, Zenker G.A. 3217, Jul 1904: holotype: B[B 10 0154211]; isotypes BR[BR0000008498991]; G[G00011576 G00011761]; K[K000198837] ; S[S10-21236]; WU[WU0025885].

Description

Tree, 15–30 m tall, d.b.h. up to 60 cm; stilt roots or buttresses absent, trunk fluted. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches glabrous. Leaves: petiole 4–12 mm long, 1 mm in diameter, glabrous, grooved towards the base, blade inserted on the side of the petiole; blade 8.5–15.5 cm long, 3–6 cm wide, elliptic to obovate, apex acuminate, acumen 1–1.5 cm long, base decurrent to cuneate, papyraceous to subcoriaceous, below glabrous when young and old, above glabrous when young and old, concolorous; midrib raised above, above glabrous when young and old, below glabrous when young and old; secondary veins 9 to 12 pairs, glabrous below; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old or young foliate branches, axillary. Flowers with 9 perianth parts in 2 whorls, 1 per inflorescence; pedicel 1–2 mm long, 1 mm in diameter, glabrous; in fruit 30 mm long, 3–4 mm in diameter, glabrous; bracts 3 to 7, several basal and one upper towards the lower half of pedicel, basal bracts ca. 1 mm long, ca. 1 mm wide; upper bracts ca. 1 mm long, ca. 1 mm wide; sepals 3, valvate, free, 2–3 mm long, 2–3 mm wide, ovate, apex acuminate, base truncate, green, glabrous outside, glabrous inside, margins flat; petals basally fused, tube 6–15 mm long, red, inner and outer whorl not differentiated, equal; lobes 10–23 mm long, 5–10 mm wide, ovate, apex acute, bright green-white to yellow, margins wavy, glabrous outside, glabrous inside, spreading horizontally; stamens numerous, in 3 to 4 rows, ca. 2 mm long, broad; connective discoid, glabrous, yellow; staminodes absent; carpels fused into a single structure, ca. 2 mm long, stigma bilobed, slightly capitate, glabrous. Fruit syncarpous, sessile, ca. 50 mm long, ca. 40 mm in diameter, globose, apex rounded, glabrous, rugulose, longitudinally 6–8 ribbed, green when unripe; seeds not counted, 8–10 mm long, 5–7 mm in diameter, ellipsoid; aril absent.

Distribution

Known from Nigeria and Cameroon; in Cameroon known from the South and South-West regions.

Habitat

An infrequent species; in lowland rain forests on non-inundated soils. Altitude 0–550 m a.s.l.

Local and common names known in Cameroon

Avom (van Andel 4177).

IUCN conservation status

Endangered (EN) (Cosiaux et al. 2019v).

Uses in Cameroon

None reported.

Notes

Isolona pleurocarpa is distinguished by the combination of these characters: young leaves glabrous, leaf blade inserted on the side of the petiole and decurrent to narrowly cuneate at base, midrib proximally depressed above, corolla lobes narrowly ovate to ovate with a narrowed base and an acute apex, undulate-wavy on the margins when dried.

Specimens examined

South Region: NE of Mt Elephant ca 20 km SE of Kribi, 2.8°N, 10.03°E, 10 February 1970, Bos J.J. 6298 (WAG); mountain chain Ngovoyang 42 km in forest from Bikiliki village situated between Bipindi and Lolodorf, 3.18°N, 10.53°E, 19 February 2012, Couvreur T.L.P. 402 (WAG,YA); Colline Nkolo Manga (20 km SE Kribi), 2.95°N, 9.916°E, 16 April 1968, Letouzey R. 9341 (P,WAG); Elephant Mont, 2.8°N, 10.01°E, 22 October 2001, van Andel T.R. 4177 (KRIBI,WAG,YA); Bipindi, 3.08°N, 10.41°E, 1895, Zenker G.A. 1716 (B,G,M,P,WAG); Bipindi, 3.08°N, 10.41°E, 01 January 1918, Zenker G.A. 22 (P,WAG); Mbiave, 3.21°N, 10.61°E, 01 January 1913, Zenker G.A. 267 (A,B,BR,C,G,M,MO,U,WAG); Bipindi, 3.08°N, 10.41°E, 01 April 1904, Zenker G.A. 3038 (B,COI,G,K,L,M,MO,P,S,WAG); Bipindi, 3.08°N, 10.41°E, 01 July 1904, Zenker G.A. 3217 (B,BR,G,K,L,M,S,WAG); Bipindi, 3.08°N, 10.41°E, 01 January 1908, Zenker G.A. 3433 (BR,COI,G,G,L,M,M,MO,P,S); Bipindi, 3.08°N, 10.41°E, 01 January 1908, Zenker G.A. 3540 (G,K,L,M,M,MO); Bipindi, 3.08°N, 10.41°E, 01 January 1909, Zenker G.A. 3921 (B,BR,COI,COI,G,L,M,M,MO,P,S); Bipindi, 3.08°N, 10.41°E, 01 January 1913, Zenker G.A. 4704 (BM,BR,G,K,L,M,P,S); Bipindi, 3.06°N, 10.38°E, 01 November 1919, Zenker G.A. 95 (BM). South-West Region: Southern Bakundu Forest 3 km from Kindongi Camp, 4.55°N, 9.416°E, 02 May 1972, Leeuwenberg A.J.M. 9784 (B,BR,C,H,K,LD,M,MO,P,WAG,YA); Korup National Park, 5.06°N, 8.783°E, 13 April 1978, Thomas D.W. 349 (K).

Isolona thonneri (De Wild. & T. Durand) Engl. & Diels, Monogr. Afr. Pflanzenfam. 6: 83, 1901

Fig. 40; Map 5G

Monodora thonneri De Wild. & T. Durand, Bull. Soc. Roy. Bot. Belg., Compt. Rend. 38: 12, 1899.

= Diospyros oblongicarpa Gürke, Bot. Jahrb. Syst. 43: 200, 1909. Type. Cameroon. South Region, Bipindi, Zenker G.A. 3471, 1908: holotype B n.v.: isotype: K[K000199009]; US[US03899523]; WU[WU0040298].

Type

Democratic Republic of the Congo. Equateur; Massanga (près de Monveda), Thonner F. 104, 24 Sep 1896: lectotype, designated by Boutique (1951b), p. 263, sheet here designated: BR[BR0000005113330]; isotypes: BR[BR0000005112715, BR0000005113040].

Description

Tree to shrub, 3–10 m tall, d.b.h. up to 25 cm; stilt roots or buttresses absent, trunk not fluted. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches glabrous. Leaves: petiole 3–8 mm long, 1–2 mm in diameter, glabrous, grooved, blade inserted on the side of the petiole; blade 11–20 cm long, 4–7.5 cm wide, elliptic to obovate, apex acuminate, acumen 1–2 cm long, base decurrent to cuneate, coriaceous to subcoriaceous, below glabrous when young and old, above glabrous when young and old, concolorous; midrib raised above, above glabrous when young and old, below glabrous when young and old; secondary veins 9 to 12 pairs, glabrous below; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old or young foliate branches, axillary. Flowers with 9 perianth parts in 2 whorls, 1 to 2 per inflorescence; pedicel 5–18 mm long, ca. 1 mm in diameter, glabrous; in fruit 8–10 mm long, 3–4 mm in diameter, glabrous; bracts 3 to 7, several basal and one upper towards the lower half of pedicel, basal bracts ca. 1 mm long, ca. 1 mm wide; upper bracts ca. 2 mm long, 1 mm wide; sepals 3, valvate, free, 2–3 mm long, 1–2 mm wide, ovate, apex acute, base truncate, dark green, glabrous outside, glabrous inside, margins flat; petals basally fused, tube 3–6 mm long, inner and outer whorl not differentiated, equal; lobes 14–31 mm long, 3–5 mm wide, linear to lorate (strap-shaped), apex acute, green, margins flat, glabrous outside, glabrous inside, pendulous; stamens numerous, in 3 to 4 rows, ca. 2 mm long, broad; connective discoid, glabrous; staminodes absent; carpels fused into a single structure, ca. 2 mm long, stigma bilobed, slightly capitate, sparsely pubescent. Fruit syncarpous, sessile, 40–60 mm long, 20–35 mm in diameter, ellipsoid, apex rounded, glabrous, smooth, not or faintly ribbed, color unknown; seeds not counted, 15–18 mm long, 8–9 mm in diameter, ellipsoid; aril absent.

Figure 40. 

Isolona zenkeri A flowering branch B flower C fruit. Isolona campanulata D flowering branch; E flower E corolla lobe opened G fruit. Isolona thonneri H flowering branch I flower J fruit A from Le Testu 5117 B from Le Testu 8001 C from Klaine 2675 D–G from Aubréville 6 H, I from Vrydagh 34 J from Lebrun 2032. Drawings by Hélène Lamourdedieu, Publications Scientifiques du Muséum national d’Histoire naturelle, Paris; modified from Le Thomas (1969b, pl. 67, p. 359).

Distribution

A central African species, known from Cameroon to Gabon and the Democratic Republic of Congo; in Cameroon known from the South and East regions.

Habitat

An infrequent species; in lowland rain forests, near rivers and swamps. Altitude 450–750 m. a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Least Concern (LC) (Cosiaux et al. 2019w).

Uses in Cameroon

None reported.

Notes

Isolona thonneri is characterized by long, narrowly elliptic to linear and glabrous corolla lobes. In the absence of flowers, it is hard to distinguish from I. dewevrei.

Specimens examined

East Region: Près de Banana 10 km ENE de Moloundou, 2.08°N, 15.28°E, 17 April 1971, Letouzey R. 10682 (P,WAG,YA); near Ndongo ca 45 km WNW of Moloundou, 2.16°N, 14.83°E, 15 March 1973, Letouzey R. 12085 (K,P); Près Ndongo à 45 km WNW de Moloundou, 2.15°N, 14.86°E, 16 March 1973, Letouzey R. 12111 (BR,K,P,WAG,YA); près Ndongo à 40 km WNW de Moloundou, 2.15°N, 14.86°E, 16 March 1973, Letouzey R. 12115 (BR,K,P,WAG,YA). South Region: Colline Ongongondje près Akonekye 15 km NW d’Ambam, 2.46°N, 11.16°E, 23 March 1970, Letouzey R. 10205 (BR,COI,K,P,WAG,YA); Inselberg d’Akookas pres du village d’Akookas 38 km au sud est d’Ebolowa, 2.71°N, 11.27°E, 15 March 2001, Parmentier I. 1943 (BRLU,WAG); Inselberg d’Akookas pres du village d’Akookas 38 km au sud est d’Ebolowa, 2.71°N, 11.27°E, 15 March 2001, Parmentier I. 1961 (BRLU,WAG).

Isolona zenkeri Engl., Notizbl. Bot. Gart. Berlin-Dahlem 2: 301, 1899

Figs 40, 41; Map 5H

Type

Cameroon. South Region; Bipindi, Zenker G.A. 1186, 1896: holotype: B[B 10 0154218]; isotypes: BM n.v., G[G00011574]; K[K000199013]; WU[WU0025863].

Description

Tree to shrub, 7–15 m tall, d.b.h. up to 15 cm; stilt roots or buttresses absent, trunk not fluted. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches glabrous. Leaves: petiole 2–6 mm long, ca. 2 mm in diameter, glabrous, slightly grooved, blade inserted on top of the petiole; blade 16–23 cm long, 6.5–8.5 cm wide, oblong to oblanceolate, apex abruptly acuminate, acumen 1–2 cm long, base rounded to acute, coriaceous, below glabrous when young and old, above glabrous when young and old, concolorous; midrib raised above, above glabrous when young and old, below glabrous when young and old; secondary veins 11 to 13 pairs, glabrous below; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on young foliate branches, axillary. Flowers with 9 perianth parts in 2 whorls, 1 to 2 per inflorescence; pedicel 3–7 mm long, ca. 1 mm in diameter, glabrous; in fruit 5–15 mm long, 2–3 mm in diameter, glabrous; bracts 2 to 4, all basal, 1 mm long, 1 mm wide; sepals 3, valvate, free, 2–5 mm long, 2–4 mm wide, ovate, apex acute, base truncate, green to brown-red, glabrous outside, glabrous inside, margins flat; petals basally fused, tube 4–7 mm long, inner and outer whorl not differentiated, equal; lobes 15–25 mm long, 3–4 mm wide, lorate (strap-shaped) to oblong, apex acute, light yellow to light green, margins curved inwards, glabrous outside, glabrous inside, erect over receptacle, verrucose when dried; stamens ca. 40, in 3 to 4 rows, ca. 2 mm long, broad; connective discoid, glabrous, cream; staminodes absent; carpels fused into a single structure, ca. 3 mm long, stigma bilobed, slightly capitate, glabrous. Fruit syncarpous, sessile, 30–65 mm long, 15–30 mm in diameter, ellipsoid to globose, apex rounded, glabrous, smooth, faintly ribbed to longitudinally ribbed, green turning yellow when ripe; seeds not counted, 15–20 mm long, 8–10 mm in diameter, ellipsoid; aril absent.

Figure 41. 

Isolona zenkeri A tree in rain forest B detail of funneled trunk C detail of leaves, upper side, note raised midrib D flowers, side view, note erect lobes E flowering and fruiting branch A, B Sosef 2291, Gabon C Sosef 2350, Gabon D, E Sosef 2322, Gabon. Photos Thomas L.P. Couvreur.

Distribution

Known from Cameroon to the west of Republic of Congo; in Cameroon known from the South and Littoral regions.

Habitat

A fairly infrequent species, growing in lowland rain forests. Altitude 0–800 m a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Least Concern (LC) (Cosiaux et al. 2019x).

Uses in Cameroon

None reported.

Notes

Isolona zenkeri is characterized by its coriaceous corolla lobes with incurved margins, erect above the receptacle, and verrucose when dried.

Specimens examined

South Region: Bipinde, 3.26°N, 10.20°E, 16 June 1918, Annet E. 359 (WAG); 12 km from Kribi N of Ebolowa road between Kribi aifield and Kienke R, 2.88°N, 9.983°E, 18 June 1969, Bos J.J. 4866 (BR,K,LM,MO,P,POZG,WAG,YA); 6 km N of km Kribi-Lolodorf, 3.08°N, 10.25°E, 12 March 1970, Bos J.J. 6522 (BR,K,P,WAG,YA); Campo-Ma’an area Bibabimvoto, 2.25°N, 10.36°E, 01 February 2000, Elad M. 1269 (WAG); Campo-Ma’an area Ebianemeyong, 2.46°N, 10.29°E, 24 May 2002, Elad M. 1545 (KRIBI,WAG); 3 km S of Kwambo and 6 km WSW of Bipindi, 3.05°N, 10.36°E, 19 January 1987, Manning D. 1453 (MO); Campo-Ma’an area Bifa, 2.65°N, 10.28°E, 12 October 2001, Tchouto Mbatchou G.P. BIFAX_2 (WAG); Campo-Ma’an area Bibabimvoto, 2.21°N, 10.01°E, 13 May 2000, Tchouto Mbatchou G.P. 2855 (KRIBI,WAG,YA); Campo-Ma’an area Bibabimvoto, 2.25°N, 10.04°E, 24 August 2000, Tchouto Mbatchou G.P. 3009 (KRIBI,WAG,YA); Bipindi, 3.08°N, 10.41°E, 1896, Zenker G.A. 1186 (B,BM,G,K); Bipindi, 3.08°N, 10.42°E, 01 January 1907, Zenker G.A. 3375 (P); Bipindi, 3.08°N, 10.41°E, 01 January 1908, Zenker G.A. 3471 (US); Bipindi, 3.08°N, 10.41°E, 01 January 1912, Zenker G.A. 4405 (G,K,MO).

Letestudoxa Pellegr., Bull. Mus. Natl. Hist. Nat. 26: 654, 1920

Thomas L.P. Couvreur

Type species

Letestudoxa bella Pellegr.

Description

Lianas, to 40 m tall, d.b.h. up to 4 cm; stilt roots or buttresses absent. Indumentum of simple hairs. Leaves: petiole 3–12 mm long, 1–6 mm in diameter, pubescent to glabrous, slightly grooved, blade inserted on top of the petiole; blade 5–28 cm long, 3–12 cm wide, elliptic to obovate to oblong, apex acuminate to emarginate, base rounded to cordate; secondary veins 11 to 20 pairs; tertiary venation percurrent to indistinct. Individuals bisexual; inflorescences ramiflorous on old leafless branches, extra axillary. Flowers with 9 perianth parts in 3 whorls, 1 per inflorescence; pedicel 3–11 mm long, 1–7 mm in diameter; in fruit 3–7 mm long, 1–3 mm in diameter; bracts 2, one basal and one upper towards the lower half of pedicel; sepals 3, valvate, completely fused forming a nearly closed cup but tearing open at anthesis, 10–20 mm long; petals free, outer petals longer than inner; outer petals 3, imbricate, 30–55 mm long, 15–55 mm wide, ovate, apex acute to rounded, base attenuate; inner petals 3, imbricate, 15–35 mm long, 10–25 mm wide, elliptic to ovate, apex acute, base attenuate to acute; stamens up to 800, in 16 to 20 rows, 2–10 mm long, broad; connective flattened, pubescent, red; staminodes absent; carpels free, 150–175, 2–2.5 mm long, stigma capitate, pubescent. [Fruits only known from L. bella] Fruit pseudosyncarpous ca. 45 mm long, ca. 50 mm in diameter, globose; individual carpels sessile, 125 to 150 carpels, apex rounded to apiculate; seed 1, 15–16 mm long, 4–8 mm in diameter, ellipsoid; aril present.

A genus of lianas with three known species, from Angola (Cabinda), Cameroon, Gabon and Republic of Congo; in Cameroon two species, none endemic.

Lestestudoxa is distinguished by the lianescent habit and pseudosyncarpous fruits (carpels fusing after pollination to form a single fruiting unit, similar to those of the genus Duguetia, but the latter being trees) and the sepals completely fused around the floral bud and tearing at anthesis. The only other lianescent Annonaceae liana in Africa with pseudosyncarpous fruits is Pseudartabotrys, a monospecific genus endemic to Gabon (Le Thomas 1969b).

Taxonomy

Chatrou (1998).

Key to the species of Letestudoxa in Cameroon

1 Leaves generally elliptic (sometimes obovate), 5–18 cm long; upper bract not clasping base of flower buds L. bella
Leaves generally obovate (sometimes oblong), 15–28 cm long; upper bract clasping (amplexicaul) around the base of flower buds L. lanuginosa

Letestudoxa bella Pellegr., Bull. Mus. Natl. Hist. Nat. 26: 655, 1920

Figs 42, 43; Map 5I

= Letestudoxa grandifolia Pellegr., Bull. Mus. Natl. Hist. Nat. 26: 656, 1920. Type. Gabon. Nyanga, Ilou Micongo, Le Testu G.M.P.C. 1442, 4 Nov 1908: holotype: P[P00364780]; isotype: BM[BM000546387].

= Pachypodanthium simiarum Exell & Mendonça, J. Bot. 74 (Suppl.): 14, 1936. Type. Angola. Maiombe, Belize, Gossweiler J. 6971, 16 Fev 1917: holotype: BM[BM000067635]; isotypes: COI[COI00004878]; LISC[LISC000102, LISC000101, LISC000098, LISC000099, LISC000100].

Type

Gabon. Nyanga; Midounga, near Tchibanga, Le Testu G.M.P.C. 1637, 24 Oct 1910: holotype: P[P00364779]; isotype: BM[BM000546388].

Description

Liana, 16–40 m tall, d.b.h. up to 4 cm; stilt roots or buttresses absent. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches densely pubescent. Leaves: petiole 3–10 mm long, 1–4 mm in diameter, pubescent to glabrous, slightly grooved, blade inserted on top of the petiole; blade 5–18 cm long, 3–8 cm wide, elliptic to obovate, apex acuminate to emarginate, acumen 0.5–1 cm long, base rounded to cordate, coriaceous, below densely pubescent when young, densely pubescent when old, above glabrous when young and old, concolorous; midrib sunken or flat, above glabrous when young and old, below pubescent when young and old; secondary veins 12 to 20 pairs, pubescent below; tertiary venation percurrent to indistinct. Individuals bisexual; inflorescences ramiflorous on old leafless branches, extra axillary. Flowers with 9 perianth parts in 3 whorls, 1 per inflorescence; pedicel 3–6 mm long, 1–3 mm in diameter, pubescent; in fruit 3–7 mm long, 1–3 mm in diameter, pubescent; bracts 2, one basal and one upper towards the lower half of pedicel, basal bract 5–7 mm long, 3–5 mm wide; upper bract 6–12 mm long, 4–7 mm wide, not clasping the flower bud; sepals 3, valvate, completely fused, tearing at anthesis, 10–20 mm long, base truncate, brown, densely pubescent outside, densely pubescent inside, margins flat; petals free, outer petals longer than inner; outer petals 3, 30–55 mm long, 15–55 mm wide, ovate, apex acute, base attenuate, yellow to orange with pinkish margins, margins crisped, densely pubescent outside, pubescent inside; inner petals 3, imbricate, 15–30 mm long, 10–25 mm wide, elliptic to ovate, apex acute, base attenuate to acute, yellow to orange with red marginal zone, margins wavy, densely pubescent outside, pubescent inside; stamens numerous, 2–3 mm long, broad; connective flattened, pubescent, red; staminodes absent; carpels free, around 175, ovary ca. 2 mm long, stigma capitate, pubescent. Fruit pseudosyncarpous, ca. 45 mm long, ca. 50 mm in diameter in total, globose; individual carpels sessile, 125 to 150 carpels, obovoid to obtrulloid, apex rounded to apiculate, sparsely pubescent, 6 to 7 ribbed, green turning red when ripe; seed 1 per monocarp, 15–16 mm long, 4–8 mm in diameter, ellipsoid; aril present, light brown.

Figure 42. 

Letestudoxa lanuginosa A flowering branch, with one open flower and one flower bud, note sepals completely fused B detail of lower side of leaf blade showing dense pubescence C flower, bottom view D stamens, side and front views E carpels, note long elongated stigma F longitudinal section of receptacle G flower diagram. Letestudoxa bella H detail of lower side of leaf blade showing pubescence I flower bud, note sepals completely fused A–G from Le Testu 9320; 8–9 from Le Testu 8362. Drawings by Hélène Lamourdedieu, Publications Scientifiques du Muséum national d’Histoire naturelle, Paris; modified from Le Thomas (1969b, pl. 17, p. 99).

Distribution

Known from Angola, Cameroon to Gabon and in the Republic of Congo; in Cameroon known from the South region.

Habitat

Growing in lowland primary and secondary rain forests. Altitude 50–750 m a.s.l.

Local and common names known in Cameroon

None recorded.

IUCN conservation status

Not evaluated.

Uses in Cameroon

None reported.

Notes

Letestudoxa bella is characterized by its mostly elliptic leaves (sometimes obovate too) which are generally smaller (5–18 cm) than those of L. lanuginosa (15–28 cm). In addition, in fresh material, L. lanuginosa has a bullate upper surface (versus a more leathery smooth upper surface in L. bella). In flower, L. lanuginosa is characterized by the upper bract clasping the flower bud, which is not the case in L. bella.

Specimens examined

South Region: 26 km E of confluent Ntem River and Akom River near Ebolowa, 2.29°N, 11.86°E, 05 March 1970, Letouzey R. 10097 (BR,P,P,YA); Tom (Nyabessan), 2.43°N, 10.52°E, 04 March 1963, Raynal J. 10195 (P,YA).

Letestudoxa lanuginosa Le Thomas, Adansonia sér. 2, 6: 145, 1966

Figs 42, 43; Map 6A

Type

Gabon. Woleu-Ntem; Ncout, Le Testu G.M.P.C. 9320, 13 Oct 1938: lectotype, sheet here designated: P[P00364781]; isotypes: P[P00364782, P00364783].

Description

Liana, 20 m tall, d.b.h. 2–3 cm in diameter; stilt roots or buttresses absent. Indumentum of simple hairs; old leafless branches densely pubescent to tomentose, young foliate branches densely pubescent to tomentose. Leaves: petiole 6–12 mm long, 3–6 mm in diameter, densely pubescent, slightly grooved, blade inserted on top of the petiole; blade 15–28 cm long, 7–12 cm wide, obovate to sometimes oblong, apex rounded or emarginate or obcordate or mucronate, acumen 0.1–1.9 cm long, base cordate, coriaceous, below densely pubescent when young, densely pubescent when old, above glabrous when young and old, concolorous; midrib sunken or flat, above densely pubescent when young and old, below densely pubescent when young, densely pubescent when old; secondary veins 11 to 18 pairs, densely pubescent below; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old leafless branches, extra axillary. Flowers with 9 perianth parts in 3 whorls, 1 per inflorescence; pedicel 3–11 mm long, 4–7 mm in diameter, densely pubescent; in fruit unknown; bracts 2, one basal and one upper towards the upper half of pedicel, basal bract 8–13 mm long, 10–15 mm wide; upper bract 8–18 mm long, 6–10 mm wide, clasping the flower bud; sepals 3, valvate, completely fused, tearing at anthesis, 10–20 mm long, base truncate, brown, pubescent outside, pubescent inside, margins flat; petals free, outer petals longer than inner; outer petals 3, imbricate, 30–50 mm long, 30–40 mm wide, ovate, apex rounded to acute, base attenuate, orange to red, margins crisped, densely pubescent inside, pubescent outside; inner petals 3, imbricate, 25–35 mm long, 15–25 mm wide, elliptic to ovate, apex acute, base attenuate, claw ca. 5 mm long, orange to red, margins wavy, densely pubescent inside, pubescent outside; stamens 750 to 800, in 16 to 20 rows, 7–10 mm long, broad; connective flattened, pubescent; staminodes absent; carpels free, 150, ovary 2–2.5 mm long, stigma capitate, pubescent. Fruits unknown.

Figure 43. 

Letestudoxa bella A leaf, upper side B fruit, a pseudosyncarpous fruit C fruit, top view, note the large sepal remains. Letestudoxa lanuginosa D habit, liana climbing on tree trunk E leaf, upper side F leaf, lower side G detail of young flower bud, not completely enclosing sepals A–C Couvreur 600, Gabon D–G Couvreur 1148, Ma’an, Cameroon. Photos Thomas L.P. Couvreur.

Map 6.