Biology subjects

Cheek, M.

Publications and source records attributed to Cheek, M..

At least 19 recordsLinked to original sources

bioRxiv2026

Denisea fonensis (Thismiaceae), a new genus and species of mycoheterotroph from Guinea.

Distinct from plants which directly parasitise other plants (parasites), non-photosynthetic mycoheterophic plants (MHPs, previously known as achlorophyllous mycotrophs or saprophytes) depend upon fungal hyphae for their carbon and have been viewed as cheaters or parasites in their fungal partnerships rather than mutualistic as in most other plant-mycorrhizal interactions. Over 400 such species in 87 genera and 11 families are recorded which maintain this lifeform through their life-cycle, while an estimate 30,000 further species, mainly orchids, depend on this mode of life to establish themselves from seeds. In most cases the fungal partners and the ultimate carbon sources, usually autotrophic plants, are unknown. High fungal specificity is the norm in those MHPs researched. We describe a new MHP genus and species, Denisea fonensis that we discovered in the Simandou range of the Republic of Guinea, West Africa in October 2025 on the footprint of a mining project. While clearly placed in Dioscoreales (which has three MHP families), the features of Denisea are so unusual that it was not initially clear in which family to place it. Finally, with molecular data we placed Denisea in Thismiaceae, corroborated by morphology. The new discovery is all the more unexpected as this is the first record of Thismiaceae from West Africa. Until now the family has only been recorded in Africa from three species of the very different genus Oxygyne, of Cameroon and Central African Republic. We provisionally assess Denisea fonensis as Critically Endangered since less than ten individuals are recorded in only a few square metres at one site, where there are imminent threats from animals. We propose urgent measures to conserve this species to reduce the risk of global extinction that has eliminated other African MHP species such as Oxygyne triandra, and further research to determine the fungal and autotrophic plant partners of this remarkable plant genus.

plant biology↗

bioRxiv2026

Ardisia mela (Primulaceae) a new threatened, herbaceous species of Ardisia subgen. Kamardisia from the forest of the Crystal Mts, Gabon.

Ardisia mela is formally described from the forests of the Crystal Mts, Gabon based on a specimen collected in 1968 and informally described in 1979 by Taton as Species 2. Despite the proximity of the collection to a road, and a resurgence of botanical surveys in the Crystal Mts in recent years, the species appears not to have been refound, and as it occurs in a logging concession and areas of cleared forest can be seen in the vicinity of the collection site, the species is considered threatened and provisionally assessed as Critically Endangered using the 2012 IUCN standard.

plant biology↗

bioRxiv2026

A Taxonomic Revision of the Monocaul Phanerophyte Ardisia (Primulaceae) of Gabon

Monocaul Ardisia (Primulaceae) have a single, vertical, woody stem and spiral phyllotaxy. They range from 30 cm to 100 cm tall. Three species of this architectural group, Ardisia mayumbensis, A. hallei and A. bracteata, have been recorded from Gabon hitherto. In this taxonomic revision we show that A. mayumbensis does not occur in Gabon, and we describe three new species. Two of these, Ardisia doudou sp. nov.and A. mica sp.nov., are endemic to Gabon and one, A. litterbin sp.nov, is found in both Gabon and Republic of the Congo. Ardisia hallei and A. bracteata are redescribed. All five species have a litter-gathering habit with a terminal funnel of leaves, and two of these species, Ardisia doudou and Ardisia litterbin, also possess adventitious roots in the distal part of the stem, a well-established strategy found in litter-gathering forest species of other plant families in tropical Africa. We provisionally assess the conservation status of all five taxa using the 2012 IUCN standard, finding that all monocaul Ardisia in Gabon fall within threatened categories. Two of the species, Ardisia bracteata and A. mica, are known from single collections and have not been seen for 164 and 63 years respectively and are conceivably extinct although further surveys are needed to establish this. We employ new characters in delineating and describing African Ardisia using leaf thickness and oil gland data.

Plant Biology↗

bioRxiv2026

Afrothismia lovettii sp. nov. (Afrothismiaceae) Critically Endangered (Possibly Extinct) and endemic to the Kihansi Falls Forest, Tanzania

The fully mycotrophic (or mycoheterotrophic) non-photosynthetic Afrothismia lovettii Cheek sp. nov. (Afrothismiaceae), is described and illustrated from the Kihansi Gorge Forest of the Udzungwa Mts, Tanzania where a World Bank-funded hydroproject may have resulted in its extinction, together with the possible extinction of two other narrowly endemic species of mycoheterophic plant, Kihansia lovettii and Kupea jonii (Triuridaceae). The co-incidence of these three species makes (or made) the Kihansi Falls the most important site for species diversity of mycotrophic plants in eastern Africa. In terms of numbers (three) of strict endemic species of this lifeform, the Kihansi Falls is or was, the most important site in Africa together with Mt Kupe in Cameroon. Afrothismia lovettii is similar and may be related to Afrothismia mhoroana Cheek of the Uluguru Mts with which it was confused, differing inter alia in the mainly white, short (6.5-10 mm long), {+/-}monomorphic perianth lobes (vs red, 12 and 20 mm long, di- or tri-morphic) and glabrous (vs hairy) adnate staminal filaments. The provisional extinction risk assessment for Afrothismia lovettii is Critically Endangered (Possibly Extinct) (CR B1ab (iii)+2ab(iii)) using the IUCN 2012 categories and criteria, due to the small area of occupancy and the forest habitat degradation (loss of waterfall spray) resulting from the construction of the World Bank financed Kihansi dam.

plant biology↗

bioRxiv2026

Two new threatened Inversodicraea (Podostemaceae) species from Sierra Leone: I. joulei and I. lebbiei

Two threatened new species of Podostemaceae belonging to the genus Inversodicraea, I. joulei and I. lebbiei, both from the Republic of Sierra Leone, are described and illustrated. A first record in Sierra Leone of the genus Lestestuella is also reported. Inversodicraea is the most species-rich genus of Podostemaceae in Africa and now comprises 38 species. Inversodicraea joulei is easily recognised because it has a persistent spine distally on the median rib of each fruit valve, and scattered, membranous scale-leaves with broadly rounded apices, while Inversodicraea lebbiei is distinct in having narrowly triangular robust scale-leaves which are inrolled, spreading distally, and completely covering the stem, arranged in five ranks. Inversodicraea joulei is known from a single location with three sites while I. lebbiei is known from two locations each with one site. Using the latest IUCN Red List guidance, Inversodicraea joulei is assessed as Critically Endangered and I. lebbiei is assessed as Endangered, due to threats from dam construction projects, agricultural practices and mining activities, resulting in high levels of siltation on rocks in the fast-flowing rivers where these species grow.

plant biology↗

bioRxiv2026

Afrothismiaceae West of the Dahomey gap: Afrothismia fonensis sp. nov. Critically Endangered and endemic to Pic de Fon forest, Simandou, Republic of Guinea

The fully mycoheterotrophic, non-photosynthetic Afrothismia fonensis Cheek & G.Delhaye sp. nov. (Afrothismiaceae), is described and illustrated from two sites in submontane forest in or adjacent to the Pic de Fon Foret Classee, Simandou Range, Republic of Guinea. This is the first record of the genus and family in West Africa west of Nigeria. The new species is remarkable for its small size, and for being unique in the genus in the entirely connate intertepaline lobes (in other species of the genus they are free or only partly united) and the longitudinal ridges on the outer perianth tube (unknown in other species). The provisional extinction risk assessment for Afrothismia fonensis is Critically Endangered (CR B1ab (iii)+2ab(iii)+D1) using the IUCN 2012 categories and criteria, due to less than 50 individuals being recorded, and due to the both the very small range and the immediate threats from foraging by red river hogs, trampling by cattle and from de-watering of the adjacent Oueleba iron-ore body where mining began in 2025. It should be noted that mitigation actions are expected to adequately address the risks associated with mining activities, and direct impacts to both areas of Afrothismia fonensis habitat have been fully avoided through relocation of planned infrastructure. We review the importance of the Boyboyba forest, Simandou range, as the West African centre of diversity for non-photosynthetic heteromycotrophs. This new discovery is examined in the context of other recently discovered range extensions to Guinea of Central African genera and families.

plant biology↗

bioRxiv2025

Setting priorities for the acquisition of primary plant occurrence data

AimEffective implementation of the Global Biodiversity Framework and Global Strategy for Plant Conservation depends on accurate species distribution data. Current vascular plant distribution data, while crucial for understanding terrestrial ecosystems, is often sparse and biased and requires significant expansion. This study developed a scalable approach to prioritize areas for plant occurrence data acquisition, adaptable to national priorities and providing a framework for botanical institutions to coordinate efforts and allocate resources. LocationGlobal. MethodsUsing a Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) analysis, we prioritized areas based on: (a) ecosystem service value; (b) floristic value threatened by climate or land-use change; and (c) uncertainty in species richness estimates, stratified by biome and region. Regional prioritization maps for Africa & Madagascar; East, South and Southeast Asia; Siberia and the Russian Far East; South America; and North & Central America were reviewed by botanical experts for validation. Scalability was assessed by comparing regional and global analyses. ResultsData-driven priority maps, divided into tree-dominated and grassland/deforested areas, largely received expert support. High similarity between global and regional maps demonstrated scalability. Main conclusionsOur approach provides a framework for supporting national implementation of the Global Biodiversity Framework. Variables and their weights can be tailored to national or local needs. The methods flexibility and adaptability extend to other taxonomic groups and objectives, such as protected area selection By prioritizing data acquisition, whether field-based or digital, this research promotes the efficient use of resources. A key advantage of this approach is its capacity to systematically translate expert opinion into explicit and quantitative criteria, which in turn facilitates clear communication with policymakers and funders.

plant biology↗

bioRxiv2025

Keetia tinka sp. nov. & K. kounounkan sp.nov. (Rubiaceae - Vanguerieae) new threatened forest climbers and shrubs of sandstone plateau of the Republic of Guinea.

Two new species of Keetia are described from recent botanical collections for conservation management made in surviving submontane forest areas of the sandstone plateau areas of the Republic of Guinea. Keetia kounounkan Cheek & Simbiano is a shrub of the Kounounkan Plateau towards the border of Sierra Leone, so far with a single location in gallery forest. K. tinka Cheek & Simbiano is an evergreen rainforest climber of the main part of the Fouta Djalon Highlands with two locations both in degraded forest. Both species are described, illustrated and provisionally assessed for their conservation status, the first as Critically Endangered, the second as Endangered.

plant biology↗

bioRxiv2025

A taxonomic synopsis of Heterotis (Melastomataceae), including H. kupensis, a new threatened species endemic to Mt Kupe, Cameroon

We provide a synopsis of the African genus Heterotis (Melastomataceae), recognising seven species and including the description of a new species to science Heterotis kupensis Sv. & Cheek (Melastomataceae) which is only known from Mt Kupe in the South West Region of Cameroon. In addition, we select a lectotype for H. prostrata (Thonn.) Benth., second step lectotype for H. buettneriana (Cogn. ex Buttner) Jacq.-Fel. and create the new combination H. welwitschii (Cogn.) Sv. & Cheek to replace H. cogniauxiana (A.Fern. & R.Fern.) Ver.-Lib. & G.Kadereit synon. nov. Distribution, habitat, phenology, taxonomic notes, and preliminary conservation assessments following IUCN Red List criteria are presented along with a key to the species.

plant biology↗

bioRxiv2025

Traditional uses, population, threats and conservation of the bansouman or gingerbread plum Neocarya macrophylla (Chrysobalanaceae) in Republic of Guinea (West Africa)

The flora of the Republic of Guinea (West Africa) includes nearly 4000 vascular plants species, of which c. 10% have been documented to have local socio-economic uses. These socio-economic plants provide among others, foods, medicines, materials and a source of income for the people of Guinea. One example is the bansouman or gingerbread plum, Neocarya macrophylla (Chrysobalanaceae) which is locally valued for its large, delicious seeds (nuts), edible fruit flesh, and medicinal bark (among other medicinal parts). Through a field survey of 17 local communities adjacent to Neocarya populations and the Neocarya populations themselves (780 mature individuals measured), in seven of the ten Guinean prefectures from which the species is recorded, this study documents (1) the local names, harvesting methods, uses and seed sale prices at different points in the value chain, partitions the species by habitat, records perceived threats to trees, key elements of the population structure and relative frequency of Neocarya macrophylla in Guinea, (2) map and re assesses its global conservation status as Near Threatened using the 2012 IUCN Red List categories and criteria, and (3) construct a species conservation action plan. Analysis of our survey data suggests that the largest number of mature trees (75% of the total) is in the three northern prefectures (Gaoual, Koundara, Pita) at the western foot of the Fouta massif whence seeds are exported internationally. Trees mainly occurred in shrub savannah (45% of mature individuals), with lower numbers in three other habitats. Human set bush fires appear to be the most ubiquitous threat (55%) in Guinea, but sand quarrying (18%), agricultural conversion and debarking are also key threats. Natural regeneration levels seem low compared with data from Niger with juveniles (<1 m tall) less than 10 % of the number of mature, fruiting trees (> 11 cm circumference) recorded. This is the first study focused on Neocarya macrophylla in the Republic of Guinea. In contrast the species has been the subject of numerous other papers elsewhere in its range, and we document 14 studies from Niger alone in the last 15 years. While the species is well known as an important Indigenous Fruit Tree with multiple uses in some countries, it is currently not among the top 10 such species listed for Guinea. Compared with Nigeria where numerous other uses including industrial are derived from the species, Neocarya macrophylla appears under utilised in Guinea. We suggest that studies of the chemistry and nutritional value of the seeds of Guinean Neocarya are made, since there are indications that these differ between Guinea and e.g. Niger. Follow up studies to map tree distribution in Guinea in more detail, quantify tree density, fruit yield per tree and per Ha, and duration between germination and fruiting are advised. Field trials to select elite individuals are recommended. Development of a machine to extract seeds from the endocarp (decortication) is a priority as this is the major factor limiting wild harvesting and availability of seed for human consumption.

plant biology↗

bioRxiv2025

The chemistry and morphology of Vepris wadigo (Rutaceae) a new Endangered tree of Kenyan coastal forest with the description of wadigin, a newly named alkaloid.

Here we describe Vepris wadigo based on new collections and observations of the informally published Diphasia sp. A of the Flora of Tropical East Africa. Vepris wadigo is known with certainty only from Kaya Kinondo and Kaya Timbwa forests in Kwale District of coastal Kenya where it is known as Mchikoma (Digo language). A sterile specimen from the Usambara Mts of Tanzania suggests that the species may also occur there, but this needs verification with a fertile specimen. Vepris wadigo is compared with the only other known diphasoid Vepris species of East Africa, Vepris morogoroensis of Tanzania. However, Vepris wadigo most closely resembles Vepris stolzii of Tanzania which differs in the 4-locular fruit. The chemistry of Vepris wadigo is unique among the African species of Vepris which have been analysed, since acridones, quinolines and limonoids which characterise the genus were not detected. The six compounds which were characterised included compound 1 a benzamide newly described and named in this paper as wadigin (N-(2,6-dihydroxybenzoyl)-O-methyltyramine) which is an O-glucosylated derivative of riparin III, and four lignans and neolignans not previously found or very unusual in Vepris, namely heterotropan (2), asaraldehyde (3) a degradation product of compound 4, E-asarone (4) and its isomer, Z- asarone (5). Finally, Lupeol (compound 6) which has previously been found in African Vepris. Vepris wadigo is here provisionally assessed as Endangered, EN B1ab(i-iii)+B2ab(i-iii) since only two threat-based locations are known, with an area of occupation of 8 km2 using the IUCN preferred 4 km2 cell size, although the actual total area of the habitat occupied is 22.57 Ha as calculated with Google Earth Pro. Since there are only two points the extent of occurrence cannot be calculated. Satellite imagery has shown that the area of the habitat has slowly decreased in recent decades.

plant biology↗

bioRxiv2025

Notes on the endemic and near endemic threatened rainforest plant species of Banyang Mbo Wildlife Sanctuary, SW Region, Cameroon, and Tricalysia banyangmbo sp nov. (Rubiaceae-Coffeeae) a new coffee relative.

Species new to science discovered from the Banyang Mbo Wildlife Sanctuary (BMWS) of SW Region Cameroon are reviewed and summarised, as are species listed as threatened which have been recorded, both from A. lowland evergreen forest and B. from cloud (submontane) forest. In total five globally Critically Endangered, 17 Endangered and 21 Vulnerable plant species are listed for BMWS. We describe an additional narrow endemic of BMWF, Tricalysia banyangmbo sp. nov. (Sect. Tricalysia Rubiaceae-Coffeeae), similar in the subulate calyx lobes exceeding the calyx tube, and in the stems being densely patent shortly hairy to T. sylvae Robbr. of Littoral, South Region, Cameroon and Gabon. The new species differs in having stipules in which the awn is shorter than the blade (vs vice versa), the leaf bases are rounded (vs cordate), the blades lack domatia (vs present) and the flowers are 4([ndash] 5)-merous (vs 5 &[ndash] 6&[prime] merous), the anthers lacking a distinct and conspicuous apical connective appendage (vs present). The new species is known from three collection sites with an estimated area of occupation of c. 4 km2 and is in an area threatened by oil palm plantations. We provisionally assess the species with the 2012 IUCN standard as Critically Endangered CR B1ab(iii) + B2ab(iii).

plant biology↗

bioRxiv2025

Sericanthe etugei and S. onanae (Coffeeae Rubiaceae) new cloud forest tree species Endangered in Southwest Cameroon & Bioko (Equatorial Guinea).

Two new species of cloudforest tree are described and illustrated from the Cross-Sanaga Interval within the Lower Guinea Domain. Sericanthe etugei Cheek from South West and Littoral Regions of Cameroon is species from the Cameroon Highlands, and Sericanthe onanae Cheek from South West Region, Cameroon, and Bioko (Equatorial Guinea). Sericanthe etugei is similar to Sericanthe leonardii (N. Halle) Robbr. of DRC (Kivu) and Rwanda, differing in the stipular awn 0.25 mm long (vs 1 - 4 mm), the adaxial leaf midrib and secondary nerves glabrous (vs hairy), the tertiary nerves conspicuously scalariform with the naked eye (vs not visible). The species is also similar to Sericanthe testui var. testui, differing in being a tree (vs liana), with stems not decorticating (vs decorticating), the calyx truncate in bud (vs closed) and in the pubescent ovary (vs glabrous). Sericanthe onanae is similar to S. mpassa Sonke & Robbr. of lowland forest in Gabon, differing from that species in that the leaves have an acumen (0.5 - )0.7 - 0.8(- 1.2) cm long vs 0.3 - 0.5 cm, secondary nerves are 7 - 10 (- 12) on each side of the midrib (vs 4 - 6 in S. mpassa), and that the stipules are 5 - 6.5( - 7) x 3 - 5(- 6) mm ( vs 2.5 mm long) and truncate (vs overtopped by an awn c. 1 mm long). It is also similar to S. jacfelicis (N. Halle) Robbr., differing in that the leaves are smaller (<15 cm long vs 16 - 20 cm long), the abaxial surface of the leaf blade has 7 - 10( -12) lateral nerves on each side of the midrib (vs 5 -7) and has a glossy surface and papery texture (vs matt, coriaceous), the petioles are hairy (vs glabrous), the stipules are 5 - 6.5( - 7) mm long, truncate, lacking an awn or arista, (vs 3 -4 mm long, with an arista 0.5 - 1 mm long). These two new species are both provisionally assessed as Endangered EN B2ab(iii) with the 2012 IUCN standard. The new species are briefly discussed in the context of other newly discovered submontane species from the Cross-Sanaga Interval. We speculate that the seeds of these species may be primate-dispersed.

plant biology↗

bioRxiv2024

Placodiscus bijugus (Sapindaceae) a new species of Endangered lowland evergreen forest tree from the western foothills of Mt Cameroon and from Korup National Park, Cameroon.

A new range-restricted species of Placodiscus Radlk. is described, mapped and illustrated. Placodiscus bijugus is a cauliflorous tree (4 -)5 - 10 m tall, characterised by having two pairs of leaflets, 1(- 2)-flowered cymules with minute bracts, a glabrous disk, pedicels 3 - 3.2 mm long and large (3 - 4 cm diam.), shortly stipitate, retuse fruits, orbicular in outline. It is similar to P. caudatus Pierre ex Pellegr. which has been reported from surveys in Cameroon. We discuss the typification and range of the latter species which in fact appears to be absent from Cameroon. Placodiscus bijugus is provisionally assessed as Endangered (EN B1ab(iii)+2ab(iii)) using the IUCN standard, since only three locations, with threats are reported. The species has a small, slightly range, disjunct between Mt Cameroon and Korup National Park in coastal SW region Cameroon. We review other species with this disjunct range.

plant biology↗

bioRxiv2024

Keetia magassoubiana sp. nov. (Rubiaceae - Vanguerieae) a threatened evergreen forest climber of West Africa

Keetia magassoubiana Cheek, an evergreen rainforest climber, is described and illustrated from the Republic of Guinea, Sierra Leone, Liberia and Ivory Coast. Previously indicated as being close to but different from Keetia tenuiflora (Hiern) Bridson, it differs in the glossy black, glabrous, epidermis of the distal stem internodes, the first internode rarely with very sparse red adpressed hairs (vs epidermis pale white-brown, dense pale yellow spreading hairs) and abaxial leaf surface with domed domatia with a central aperture (vs domatia absent or obscure), the secondary stem leaf bases acute (vs obtuse to truncate), the bracts forming a laciniate sheath on the distal peduncle (vs two opposite triangular bracts), the pyrene surface honeycombed with pits (vs entire). The species was earlier included within Canthium multiflorum (Schum. & Thonn.) Hiern (now K. multiflora (Schum. & Thonn.) Bridson) in the Flora of West Tropical Africa second edition. An updated key is presented to the 16 species of the genus from West Africa. Keetia magassoubiana is provisionally assessed using the IUCN standard as Endangered EN B1ab(iii) due to only five of the recorded 14 locations having extant forest habitat, and because of ongoing threats of habitat clearance mainly for agriculture, but also mining.

plant biology↗

bioRxiv2024

Keetia korupensis sp. nov. (Rubiaceae - Vanguerieae) a threatened lowland evergreen forest climber and the endemic plant species of Korup National Park, SW Region, Cameroon

A review of the strictly endemic plant species of the Korup National Park, S.W. Region, Cameroon, is presented together with consideration of the importance of Korup for global plant conservation. Eighteen strict endemic species are known, 14 of which occur in lowland evergreen forest habitat (including Keetia korupensis) and of which 3 are among the 29 grove-forming monodominant detarioid legume species for which Korup is world famous. Four of Korups endemic species are rheophytes restricted to the Mana (Ndian) River rapids and falls which is probably the most species diverse site for shrubby rheophytes on the African continent. No endemics are yet known from Korups submontane forest, possibly because this is comparatively small in extent. Keetia korupensis Cheek, a rainforest climber, is described and illustrated as strictly endemic, on current evidence, to the Korup National Park. The species differs from all other known species of the genus in its stipitate 2-seeded fruits which are twice as long as broad (vs non-stipitate and subisodiametric in most of the species) and for the 2 mm long stiff, skin-penetrating stem indumentum (vs non-injuring or soft in other long hairy species). Keetia korupensis is provisionally assessed using the IUCN standard as Vulnerable (VU D2).

plant biology↗

bioRxiv2024

Virectaria stellata (Sabiceeae Rubiaceae), a new sandstone cliff species from the Republic of Guinea with stellate hairs recorded for the first time in the Rubiaceae

Virectaria is a morphologically isolated genus of tropical African herbs or subshrubs, occurring from Senegal to Tanzania. Virectaria stellata, a new species from Guinea, is published. It is a perennial herb, with stems becoming creeping and rooting, to 60 cm long. Virectaria stellata has stellate hairs, recorded here for the first time in the family Rubiaceae. We hypothesize that the stellate hairs of this species result from horizontal gene flow from an Acanthaceae, most likely Barleria, due to their common and perhaps unique microstructure. Virectaria stellata is found in Forecariah and Kindia Prefectures in the Republic of Guinea. The species occurs in fissures in vertical sandstone rock at altitudes of 450 to 910 m, in sun or half-shade. An overview of sandstone endemic plant species in the vicinity of the new Virectaria is provided. No threats have been observed, therefore, Virectaria stellata is provisionally assessed here as Least Concern (LC).

plant biology↗

bioRxiv2024

Keetia gordonii sp. nov. (Rubiaceae - Vanguerieae) a new species of threatened forest liana from the littoral forest of Gabon

Keetia gordonii sp. nov. (Rubiaceae - Vanguerieae) a new species of forest liana from the littoral forest of Gabon is formally described and illustrated as the first endemic species of the genus from that country. On current evidence, the species appears to have three locations and is threatened by forest clearance. It is provisionally assessed using the IUCN 2012 standard as Endangered (EN B2a,b(i-iv). The new species is extremely distinctive within the genus, showing several character states previously unrecorded in Keetia. Keetia gordonii is currently unique in its genus for the massively thick, coriaceous leaf blades seen in the fruiting axillary branches (in this respect resembling a Psydrax Gaertn., vs papery or rarely thinly coriaceous in other Keetia species), and also for the globose, smooth pyrenes (vs ovoid, colliculose in other species), in which the lid crest is so vestigial that it is almost imperceptible (vs lid crest conspicuous in other species). The tanniferous seed endosperm shows a new character state for the genus being present in a continuous, solid layer in the outer part of the seed, rather than being in radial bands or diffuse as in other species of the genus. However, there is no doubt that this taxon is best placed in Keetia as opposed to Psydrax due to the disc concealed deep inside the calyx tube (vs exposed), the presence of a pyrene cap (vs none) and the stipules that lack a well-developed keel (vs keel present). Further, the presence of tanniniferous seed endosperm is not recorded in any other genus of the tribe. Keetia gordonii is currently assigned to the K. hispida species group of Guineo-Congolian Africa.

plant biology↗