Taxonomic revision of Pachyptera (Bignonieae, Bignoniaceae)

Abstract Pachyptera DC. is a small genus of neotropical lianas included in tribe Bignonieae (Bignoniaceae). The genus has a complicated taxonomic history but currently includes species distributed from Belize to Southern Amazon. Pachyptera is characterised by four main synapomorphies, namely, a papery peeling bark, prophylls of the axillary buds organised in a series of three, patelliform glands arranged in lines in the upper portions of the calyx and corolla tube. Furthermore, members of the genus also have stems with four phloem wedges in cross-section and conspicuous extrafloral nectaries between the interpetiolar region and at the petiole apex, although these characters are also shared with other genera of tribe Bignonieae. Here, we present a taxonomic revision of Pachyptera, which includes a complete list of synonyms, detailed morphological descriptions of species and an identification key, as well as information on the habitat, distribution and phenology, nomenclatural notes, taxonomic comments and illustrations of all the species. In addition, we designate three lectotypes, propose one new combination, raise one variety to species status and describe a new species. After these adjustments, a Pachyptera with five well-defined species is recognised.


Introduction
Pachyptera DC. (Bignonieae, Bignoniaceae) includes neotropical lianas that are distributed from Belize to central Brazilian Amazon, with most species restricted to wet Amazonian forests (Lohmann and Taylor 2014). The genus has a complicated taxonomic history, including a difficult generic circumscription and several poorly defined taxa. Here, a new systematic treatment of Pachyptera is proposed and five species are recognised using an integrative approach that includes data derived from a recent molecular phylogeny (Francisco and Lohmann 2017, Francisco and Lohmann submitted), coalescent approaches (Francisco and Lohmann submitted) and new morphological studies.
This new classification recognises a monophyletic genus that is characterised by four morphological synapomorphies, namely, a papery peeling bark, prophylls of the axillary buds organised in a series of three (Lohmann and Taylor 2014), patteliform glands arranged in lines on the upper portions of the calyx and corolla tube (Lohmann 2006, Lohmann andTaylor 2014). In addition, stems with four phloem wedges in cross-section, conspicuous extrafloral nectaries on the interpetiolar region and at the petiole apex also help to identify members of the genus (Lohmann and Taylor 2014).
Nearly five decades after being described, Pachyptera was synonymised into Adenocalymma Mart. ex Meisn by Baillon (1891) based on the broad and thick capsule shared amongst members of these genera. Subsequently, Bureau andSchumann (1896 [1897]) transferred P. foveolata to Adenocalymma section Pachyptera, which was characterised by villous anthers and plate-shaped glands arranged in lines outside the corolla tube, right below the lobes. At the same time, P. kerere was transferred to Adenocalymma section Hanburyophyton together with four species of Mansoa, i.e. A. alliaceum (Lam.) Miers, A. asperulum Bureau & K. Schum., A. splendens Bureau & Schum. [= Mansoa difficilis] and A. lanceolatum Miers. Pachyptera was subsequently segregated from Adenocalymma by Sprague and Sandwith (1932) and restored to generic rank, as a monotypic genus that only included P. foveolata.
Pachyptera foveolata, as circumscribed by Sprague and Sandwith (1932), consisted of a species complex that included individuals with white to crimson flowers. While the authors themselves recognised the difficulties associated with the recognition of such a diverse species, the restricted sampling prevented them from analysing the breadth of morphological variation included in this group and the recognition of a single species. Five years later, Sandwith (1937) noted that Aublet's epithet "kerere" was the correct name for P. foveolata and proposed the new combination Pachyptera kerere. Dugand (1955) also noted the high variation found in flower traits of specimens of Pachyptera kerere and described the new variety P. kerere var. erythraea Dugand. The variety P. kerere var. erythraea differs from P. kerere var. kerere in the red corolla (vs. white in P. kerere var. kerere). Gentry (1977) subsequently noted that P. kerere var. kerere and P. kerere var. erythraea also differed in the sub-exserted to exserted anthers (vs. included anthers in P. kerere var. kerere), campanulate corolla with 11-15 mm in diameter (vs. sub-bilabiate corolla with 3-7 mm in diameter in P. kerere var. kerere) and leaf blade puberulous (vs. leaf blade glabrous in P. kerere var. kerere), which led him to raise P. erythraea (Dugand) A.H. Gentry to species rank.
Although Bignonia incarnata Aubl. was described in the same work as Bignonia kerere Aubl. (1775), the close relationship between those two taxa was not noted. In fact, Bignonia incarnata was thought to be morphologically similar and perhaps more closely related to Cydista aequinoctialis (L.) Miers by various authors (see Sandwith 1937). Nearly two decades later, Gentry (1973) noted the similarity between individuals of B. incarnata and P. kerere, which led him to treat B. incarnata as a variety of P. kerere, i.e. Pachyptera kerere var. incarnata (Aubl.) A.H. Gentry. At the same time, Gentry (1973) reduced Pseudocalymma [= Mansoa] into Pachyptera due to the shared trifid tendrils, white to red or purple flowers, interpetiolar gland-fields, 3-colpate pollen and deciduous bracts. In this work, three species of Pseudocalymma were transferred to Pachyptera [P. alliacea (Lam.) A.H. Gentry, P. hymenaea (DC.) A.H. Gentry, and P. standleyi (Steyerm.) A.H. Gentry], all of which are currently placed in Mansoa. Gentry (1979) and Gentry and Tomb (1979)  In addition, a new species was described, Mansoa ventricosa A.H. Gentry, a taxon known from the type specimen plus one additional material whose placement was uncertain.

Phylogenetic based classifications of Pachyptera
While the taxonomic confusion between Mansoa and Pachyptera remained for several years, molecular phylogenetic data (Lohmann 2006) indicated that Mansoa and Pachyptera are distantly related, while the monotypic Leucocalantha Barbosa Rodrigues is closely related to Pachyptera. Leucocalantha was described based on the long and white corollas that resembled the Asian genus Millingtonia L.f. (Oroxyleae, Bignoniaceae). The genus only included Leucocalantha aromatica Barb. Rodr., which is characterised by white, pubescent and hypocrateriform corolla tubes and glands at the apices of the petioles and corollas. While the close relationship between Leucocalantha and Pachyptera was initially surprising, a careful morphological study recovered multiple morphological features shared between these taxa (e.g. stems with four phloem wedges in cross-section, corollas with glands arranged in lines on the upper portions of the tube and racemose inflorescences). This observation led to the re-establishment of Pachyptera and the inclusion of Leucocalantha into Pachyptera in a revised generic classification of the whole tribe Bignonieae (Lohmann and Taylor 2014). Under this classification, Pachyptera included four species, i.e. P. aromatica (Barb. Rodr.) L.G. Lohmann, P. erythraea (Dugand) A.H. Gentry, P. kerere and P. ventricosa (A.H. Gentry) L.G. Lohmann. This circumscription was based on morphological observations for all taxa and a molecular phylogenetic framework of the whole tribe Bignonieae that sampled half of the species of Pachyptera (Lohmann 2006); two rare and morphologically complicated species (i.e. P. erythraea and P. ventricosa) were not sampled in the phylogeny, raising their generic placement into question.
A recent phylogenetic and morphological study of Pachyptera (Francisco and Lohmann 2017) sampled all species recognised by Lohmann and Taylor (2014). In this phylogeny, Pachyptera ventricosa was more closely related to Mansoa than to other species of Pachyptera, which led to the reestablishment of Mansoa ventricosa (Francisco and Lohmann 2017). In addition, this study also provided further support for the inclusion of P. aromatica and P. erythraea into Pachyptera. As such, Pachyptera was recognised as a monophyletic genus comprising three species. However, the infra-specific classification of the P. kerere species complex remained uncertain. More specifically, it remained dubious whether P. erythraea and P. kerere var. incarnata should be treated as separate species or varieties of P. kerere.
A more comprehensive phylogenetic study of the genus (Francisco and Lohmann submitted) sampled multiple individuals of all three species of Pachyptera recognised by Francisco and Lohmann (2017) and used coalescent approaches to verify species limits. This study identified five evolutionary units that are characterised by distinct morphological features and ecological traits (Fig. 1). Within this phylogenetic framework, P. aromatica is sister to the remaining species of the genus. This species is characterised by a series of morphological autapomorphies such as stems without lenticels, prophylls of axillary buds triangular and minute, inflorescence in lax racemes, corolla hypocrateriform, anthers glabrous with straight thecae and pollen glabrous psilate-foveolate to microreticulate 4-colpate. The remaining species of the genus are divided into two main clades, the first of which includes P. erythraea and P. kerere var. incarnata (= P. incarnata), both of which are characterised by pinkish to red corollas, with ovaries densely lepidote. Pachyptera incarnata is easily distinguished by the light pink to pale purple corollas (vs. orange to red in P. erythraea), calyx tubular (vs. cupular in P. erythraea), corolla infundibuliform (vs. corolla tubular-campanulate in P. erythraea), androecium glabrous (vs. androecium puberulous in P. erythraea), anthers included (vs. anthers sub-exserted in P. erythraea) and ovaries not-bisulcate (vs. bisulcate in P. erythraea). The second clade includes P. kerere var. kerere (= P. kerere) and a Figure 1. Schematic diagram summarising phylogenetic relationships within Pachyptera, with morphological characters mapped on the diagram. Names of the terminal taxa indicate the taxon in which these species were previously included. The taxonomic updates proposed here are also indicated. Relationships depicted follow Francisco and Lohmann (submitted). new species described here (P. linearis Francisco & L.G. Lohmann), both characterised by white to cream coloured corollas, with ovaries pubescent (Fig. 1). Pachyptera kerere is separated from P. linearis by the fruit fusiform (vs. linear in P. linearis) and the seeds inflated, thick, corky and wingless (vs. seeds flattened, thin, membranaceous and winged in P. linearis).

Distribution
Almost all Pachyptera species are found in the Amazon rainforest. Only P. kerere is widely distributed while all other species have restricted distributions. Pachyptera kerere is frequent throughout the Amazon and also distributed in Central America from Panama to Belize. Pachyptera aromatica is restricted to the Brazilian Amazon. Pachyptera erythraea is endemic to the middle Magdalena River Valley of Colombia, while P. incarnata is endemic to Eastern Amazon. Pachyptera linearis is known only by a few collections from Venezuela and Colombia.

Habitats
Species of Pachyptera occur in wet terra-firme forests, generally close to water bodies or riverbanks and are also found in flooded forests such as the Brazilian igapó. The majority of Pachyptera species has seeds with thin wings that are wind dispersed, while P. kerere has thick, corky and wingless seed adapted to water dispersal (Gentry 1976). Water dispersal arose several times independently in tribe Bignonieae, mostly from wind-dispersed ancestors (Gentry 1983, Lohmann 2004. Shifts between dispersal syndromes may have driven the speciation of P. kerere (Francisco and Lohmann submitted).

Reproductive biology
Pachyptera includes great diversity of floral morphology that is associated with different pollination syndromes. Pachyptera aromatica has white, hypocrateriform corollas and nocturnal anthesis (Barbosa Rodrigues 1891). The flowers of this species are classified as "Tanaecium type" and fit the hawkmoth pollination syndrome (Gentry 1974). Tanaecium type flowers evolved multiple times within Bignonieae (Alcantara and Lohmann 2010) and are found in Tanaecium and Bignonia nocturna (Barb. Rodr.) L.G. Lohmann. Pachyptera erythraea, on the other hand, have orange to red flowers that are tubular campanulate, with sub-exserted anthers. These flowers are classified as "Martinella type" and are likely pollinated by hummingbirds (Gentry 1974).
Pachyptera incarnata, P. kerere and P. linearis share infundibuliform and dorso-ventrally compressed corollas, with two longitudinal ridges in the throat that form yellow nectar guides, as well as included anthers. Pachyptera incarnata has light pink to pale purple flowers, while P. kerere and P. linearis have white to cream flowers. These flowers are classified as "Anemopaegma type" and are pollinated by large to medium-sized bees, mainly euglossine and anthophorids (Gentry 1974).

Etymology
Pachyptera is a Latin derived name that means "with thick wings" (from Latin: pach = thick, aptera = without wings). This characteristic is found in the type species of the genus, Pachyptera kerere.

Morphology
Habit. All species of Pachyptera are lianas, although seedlings are initially herbaceous and free standing until ca. 80 cm (grow vertically).
Stems. The stems of Pachyptera exhibit four phloem wedges in cross-section, a type of cambial variation also found in Adenocalymma, Martinella, Cuspidaria, Fridericia and Tanaecium (Lohmann 2006, Lohmann andTaylor 2014). Moreover, the pith of the stem of Pachyptera is solid although a few specimens of P. aromatica also show a slightly hollow pith, a condition only known from Stizophyllum and Pleonotoma within tribe Bignonieae (Lohmann and Taylor 2014). Cylindrical to tetragonal stems are found in Pachyptera, sometimes within a single individual. Young stems are usually cylindrical, becoming tetragonal in more advanced stages of development. Tetragonal stems are only found in stems ≥ 6 cm 2 of P. aromatica but are also found in stems with a smaller diameter in other species of the genus (Francisco personal observation). Stem surface is striated and frequently bears lenticels (except in P. aromatica). The peeling bark is a morphological synapomorphy of the genus (Lohmann 2006, Lohmann andTaylor 2014).
Prophylls of the axillary buds. Prophylls of the axillary buds, referred to as "pseudostipules" in the past (e.g. Gentry 1980), exhibit several shapes and are useful generic characters within Bignonieae (Lohmann and Taylor 2014). Species of Pachyptera usually have multiple flattened and ensiform prophylls of the axillary buds (triangular and minute in P. aromatica, Fig. 5B), arranged in 3(-5) series (Fig. 2H). Sometimes the prophylls are so minute in P. aromatica that only the larger prophyll series is visible to the naked eye (Fig. 2D). The supra-numerary prophylls are an exclusive morphological synapomorphy of Pachyptera (Fig. 2G, H).
Extrafloral nectaries. Extrafloral nectaries (i.e. EFNs) are useful generic and species level markers within Bignonieae, aiding the identification of sterile materials (Seibert 1948, Lohmann andTaylor 2014). EFNs produce sugar that attracts ants which, in turn, have an important protective role against herbivores (Gentry 1974, Nogueira et al. 2015. In Pachyptera, EFNs are composed of large groups of patelliform glands located between the interpetiolar region ( Fig. 2D, G, H) and at the petiole apex, right below the junction with the petiolules. Interpetiolar gland fields are also found in other Bignonieae genera (e.g. Fridericia, Lundia, Tanaecium) and have evolved multiple times within the tribe (Nogueira et al. 2013, Lohmann andTaylor 2014). On the other hand, clusters of patelliform glands located on petioles and petiolules are rare in Bignonieae and only known from a few species (e.g. Tanaecium pyramidatum and Mansoa standleyi).
Leaves and tendrils. As with most representatives of Bignonieae, leaves of Pachyptera are 2-3-foliate, with the terminal leaflet replaced by a trifid tendril. Tendrils are often deciduous, leaving a tiny scar in the position of tendril detachment. Leaflets can be quite variable in shape, varying even within a single species. Leaflet asymmetry is striking in the group and can help in its identification. Inflorescences. The inflorescence of Pachyptera is a simple raceme that can originate from the apical and axillary buds, producing terminal and axillary inflorescences respectively. Racemes can be lax, with a well-developed central axis, ca. 6-24 cm in P. aromatica ( Fig. 2A, C) or reduced, with a short central axis (< 4.8 cm long) in all other species of the genus (Fig. 2E, I, N). In Pachyptera, inflorescence bears ca. 6-30 flowers, although only 1-2 flowers open at a time.
Calyx. The calyx of Pachyptera is tubular (cupular in P. erythraea) with grouped patelliform glands on the upper half (Figs 2M-N, 3A, F, K, P, U), a synapomorphy of the genus. Even though this feature evolved multiple times within the tribe (Lohmann 2006;Lohmann and Taylor 2014), each evolutionary event led to a different gland type and arrangement and the calyx glands found in Pachytpera have a unique mor- phology and arrangement within the tribe. These patelliform glands are conspicuous, sometimes wine-coloured ( Fig. 1M) and thought to play an important role against nectar robbers (Gentry 1974).
Corollas. More than half of Pachyptera species have infundibuliform and dorso-ventrally compressed corollas (Fig. 2I, N), with internal yellow nectar guides (Fig. 2F, O) and a villous portion where stamens and staminodes are included ( Fig. 3G, L, Q, V). The corolla tube shape of P. erythraea is slightly modified and expands above the short basal constriction and becomes tubular-campanulate (Figs 2E-F, 8B). On the other hand, P. aromatica exhibits an extraordinary and distinctive morphology, showing a corolla hypocrateriform, not compressed ( Fig. 2A-B), without nectar guides that are glabrous internally (Fig. 3B). Corolla colour is useful for species identification, ranging from white to red (see Figs 1, 2). All species display nectaries on the upper portion of the corolla tube and base of the corolla lobes that exude large globules of colourless and viscous liquid ( Fig. 2K, P), likely associated with ant-plant interactions. This feature is a morphological synapomorphy of the genus (Lohmann 2006;Lohmann and Taylor 2014).
Androecium. As with most members of Bignonieae, Pachyptera has four didynamous stamens and one staminode. Filaments are usually glabrous but puberulous in P. erythraea. The anthers are generally included, but sub-exserted in P. erythraea (Fig. 2F).
The densely villous anthers, with curved thecae, are diagnostic of the majority of Pachyptera species (Fig. 2F, O). Only P. aromatica has glabrous anthers with straight thecae. Villous anthers are an important feature of Pachyptera (except P. aromatica), only shared with Lundia.
Gynoecium. Members of Pachyptera have capitate, elliptic and ovate stigmas. While the style and stigma are always glabrous, the ovary is pubescent (Fig. 3E, T, Y) or lepidote (Fig. 3J, O). As with most representatives of Bignoniaceae, Pachyptera has bilocular ovaries, with two ovules per locule and axillary placentation. All species have well-developed nectar discs.
Fruits. Fruits are coriaceous to woody septicidal capsules, with two valves. The capsule is linear and flattened in most species (fusiform and inflated in P. kerere), puberulous, lepidote, covered with patelliform glandular trichomes and without lenticels ( Fig. 4A, C, E, G). Each valve has an inconspicuous longitudinal midline (conspicuous and raised in P. kerere).
Seeds. The seeds of Pachyptera are mostly oblong, thin, chartaceous to coriaceous, with membranaceous and hyaline wings, except from P. kerere in which seeds are irregularly circular and obcordate, thick, corky and wingless. Seed surface has provided excellent information for the systematics of various plant groups (Barthlott 1981). The seed surface of Pachyptera species is striated, with a distinctive secondary sculpture in each species. More specifically, the seed surface of P. aromatica is striated and smooth, while the seed surface of P. incarnata is striated with randomly distributed micropores and the seed surface of P. kerere is striated with two pairs of medium micropores on each striation. In P. linearis, the seed surface is striated, with the striations being regularly interrupted by lateral rays (Fig. 4B, D, F, H). The seed surface of P. erythraea is unknown.

Material and methods
Species delimitation. Molecular phylogenetic data (Francisco and Lohmann submitted) was used to aid species delimitation. While it is understood that not all species need to be monophyletic, species are evolutionary lineages that reach a status of reciprocal monophyly in advanced stages of the speciation process (de Queiroz 2007;Funk and Olmland 2003). As such, independent evolutionary units that share a unique combination of features are treated here as separate species, following Cracraft (1983). Morphological descriptions and measurements were conducted on dried specimens and fresh materials following the terminology of Lohmann and Taylor (2014), with additional terms from Radford (1974), Gentry and Tomb (1979), Hesse et al. (2009), Hickey (1979, Nogueira et al. (2013) and Weberling (1992). Rare conditions are shown within parentheses. Calyx, corolla and ovary surfaces, fruit coat, pollen surface and seed coat were analysed from representative specimens of each taxon using scanning electron microscopy (SEM) (Appendix 1). The selected structures were mounted on stubs and sputter-coated with gold. Micrographs were obtained on a Zeiss DSM 970 scanning electron microscope.
Phenology. This species flowers from June to January. Fruits were collected in January, March and July through November.
Nomenclatural note. Like Lohmann and Taylor (2014), it was not possible to locate the holotype of P. aromatica during multiple visits to the RB, where the holotype was thought to be deposited. It was also not possible to locate any isotypes of any of the collections visited, indicating that the types of P. aromatica were likely lost, just like several other type materials collected by Barbora Rodrigues in the Amazon (Mori and Ferreira 1987). As such, we here designate the illustration used in the original description of this species as the lectotype.
Taxonomic comments. P. aromatica is characterised by cylindrical (tetragonal when ≥ 6 cm 2 diameter) and vinaceous stems with greyish striations, interpetiolar extrafloral nectaries, triangular and minute prophylls of the axillary buds 3-seriated and white and hypocrateriform corollas (Figs 2A-D, 5A). This species was originally described within a monotypic genus due to its unusual morphology (Barbosa Rodrigues 1891), but was later transferred into Pachyptera based on a combination of morphological and molecular phylogenetic data (Lohmann and Taylor 2014). Pachyptera aromatica is sister to the remaining species of the genus ( Fig. 1; Francisco and Lohmann 2017, Francisco and Lohmann submitted). The phylogenetic placement of P. aromatica corroborates its placement within Pachyptera and helps to explain the unusal morphology of this taxon. Selection exerted by differ pollinators may help to explain the floral differences amongst P. aromatica and its close relatives. Pachyptera aromatica also has a series of other unusual features in the genus such as the poorly developed,  Phytologia 35(3): 186, fig. 2A  Distribution. Pachyptera erythraea is endemic to wet forest vegetation from the Magdalena River Valley in northern Colombia (Antioquia, Santander). Fig. 8.

Pachyptera erythraea (Dugand) A.H. Gentry,
Phenology. Flowers collected in January, March and July to December. Two fruiting collections are known, one collected in July and the other in September.
Phenology. Pachyptera incarnata flowers in February to May and July to December. Fruiting material has been colected in April, May, July to October and December.
Etymology. The specific epithet "incarnata" refers to the corolla colour referred by Aublet as "of flesh". Nomenclatural note. This species was first described by Aublet (1775) as Bignonia incarnata. Gentry (1973) treated B. incarnata as a variety of P. kerere due to the shared racemose inflorescences, corolla infundibuliform, villous anthers and prophylls of the axillary buds 3-seriated. Gentry (1973) distinguished the two varieties based on differences in the fruit and seed morphology. More specifically, P. kerere var. kerere included the individuals with inflated fruits, corky and wingless seeds, while P. kerere var. incarnata included the individuals with flattened fruits, thin and winged seeds. Despite the floral similarity between these two species, P. incarnata is phylogenetically more closely related to P. erythraea, with which it shares a densely lepidote ovary and flattened and linear fruits (Fig. 1). Based on the authors' new molecular phylogeny (Francisco and Lohmann submitted) and morphological data, this taxon is raised back to species-level, following Aublet (1775). As it was not possible to locate original material, the original illustration is here designated as the lectotype.
Phenology. This species flowers and fruits throughout the year. Etymology. The specific epithet is derived from vernacular name "kéréré" or "téréré" adopted by the indigenous group Galibis, from French Guiana, who use this plant as rope material.
Nomenclatural note. The original description of this species by Aublet (1775) included a mistake in the fruit illustration and description, which consists of the description of Amphilophium magnollifolium (Kunth) L.G. Lohmann instead.
Bignonia benensis was described by Britton (1990) based on a collection by Rusby 1143. This material cannot be considered a holotype because it was not cited in the protologue. Two related specimens are deposited at NY and US and one at MICH. Although there are two materials deposited at NY, only one is original material. The the other specimen is a duplicate that was originally deposited at the College of  Pharmacy Herbarium, where Britton worked. Materials from this herbarium were only later incorporated into the NY collection along with other items. Therefore, the specimen originally deposited at NY (NY313133) is here designated as lectotype.
Taxonomic comments. Pachyptera kerere is easily recognised by the infundibuliform, white to cream corollas, with densely pubescent ovary. The fusiform, woody, inflated (sometimes slightly flattened) fruit, with a conspicuous and raised longitudinal midline, is very distinctive. The seeds are irregularly circular and obcordate, corky and wingless.
Diagnosis. Pachyptera linearis is similar to Pachyptera kerere, but can be distinguished by the linear and flattened capsule (vs. the fusiform and inflated capsule of P. kerere), inconspicuous longitudinal midline on each valve (vs. conspicuous and raised longitudinal midline on each valve of P. kerere) and thin, oblong and wingless seeds (vs. corky, irregularly circular, obcordate and wingless seeds of P. kerere).
Taxonomic comments. Pachyptera linearis is characterised by white and infundibuliform corollas, with a sparsely pubescent and sparsely lepidote ovary. Furthermore, the capsule is linear, flattened, coriaceous to woody, with an inconspicuous longitudinal midline on the valves. The seeds are oblong, thin, coriaceous to woody, winged, with short membranaceous or coriaceous and hyaline wings. Pachyptera linearis shares the white infundibuliform flowers with its sister species P. kerere (Fig.1). Nevertheless, P. linearis is easily distinguible from P. kerere by the fruit morphology.