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SummaryTwo tree species are described as new to science: Rinorea spongiocarpa Achound. sp. nov. (placed in Rinorea [unranked] Brachypetalae) and R. dimakoensis Achound. sp. nov. (placed in Rinorea [unranked] Ilicifolieae). Both species occur in Cameroon, south of the Sanaga river, the first from South and East Regions, occurring in evergreen forest from Ngovayang and Lolodorf across the southern plateau to the Dja forest. The second extends also to Gabon, occurring in Cameroon in the northern part of East Region in semi-deciduous forest towards the interface with woodland habitats in the Dimako-Bertoua area. The two species are mapped and illustrated, and their affinities and conservation status according to the 2012 IUCN categories and criteria are discussed. Both R. spongiocarpa and R. dimakoensis are threatened with extinction due to habitat destruction, both are assessed as Vulnerable.

SummaryWe describe two range-restricted new species to science from the genus Impatiens (Balsaminaceae), both threatened, from lowland of the Cross-Sanaga Interval of western Cameroon. The first, Impatiens banen, appears to be restricted to an open seepage microhabitat on granitic inselbergs in the lowland-submontane forest zone of the Ebo Forest in Littoral Region and is provisionally assessed using the 2012 IUCN standard as Vulnerable. Sharing characters with Impatiens burtonii and I. mannii, it differs from both, and appears to be unique in Cameroon inter alia 1) in the bicolored united lateral petals, the upper petals being white, while the lower petals are an intense pink-purple, 2) the hairy, filamentous spur, purple with a white apex, is curved along its length, almost describing a circle. Inselberg-specific species are unusual in Impatiens.The second species, Impatiens etugei, of the I. macroptera aggregate, is restricted to rocks in the Mutel River of the Kom Wum Forest Reserve of North West Region and is assessed as Critically Endangered. Having similarities with I. mackeyana and I. letouzeyi, it differs from other species in the aggregate inter alia by having opposite leaves (vs always alternate), flower exterior white (vs pink or pink-purple), and in the dorsal petal having a pair of lateral projections (vs projections absent).

SummaryWe revise and update the records of strict and near-endemic species of the Bali Ngemba Forest Reserve, the largest known surviving patch (c. 8 km2 in area) of submontane or cloud forest in the Bamenda Highlands, Cameroon which have lost >96 % of their original forest due to human activities. Nine strict endemics, and 11 near endemics are now documented, a drop from the number recorded after the first survey in 2004, since when five of the provisionally named species have been validly published. We test the hypothesis that a further one of the provisionally named putative Bali Ngemba new species, Vepris sp. A, an 8 – 20 m tall tree from cloud forest in the 1310 – 1700 m altitudinal band, is indeed new to science. We compare it morphologically with other multicarpellate, apocarpous, trifoliolate Cameroon tree species formerly placed in the genus Oricia Pierre until they were subsumed into Vepris by Mziray (1992). These are V. trifoliolata (Engl.) Mziray and V. gabonensis (Pierre) Mziray. We conclude that Vepris sp. A is a new undescribed species here named as Vepris onanae. The new species is illustrated, mapped and its conservation status assessed as Critically Endangered using the 2012 IUCN standard due to severe fragmentation and the threats of habitat clearance from agricultural pressures at its three locations all of which remain formally unprotected. Vepris onanae appears unique among the Guineo-Congolian African oricioid species of Vepris in that it occurs in cloud forest, the other species, apart from V. renieri (G.C.C.Gilbert) Mziray of the Albertine Rift, occurring in lowland forest. It also differs in the very broad, (7.8 –) 11.3 – 18 cm wide leaflets of the flowering stems which have a 6 – 18 (– 30) mm long, narrowly triangular acumen (vs leaflets Vepris and characterise a level of sexual dimorphism more advanced than usual in the genus. We highlight the importance of protecting Bali Ngemba and other forest patches in the Bamenda Highlands if species such as Vepris onanae are not soon to become extinct.

The Checklist of the Vascular Plants of the Republic of Guinea (CVPRG) is a specimen-based, expert-validated knowledge product, which provides a concise synthesis and overview of current knowledge on 3901 vascular plant species documented from Guinea (Conakry), West Africa, including their accepted names and synonyms, as well as their distribution and status within Guinea (indigenous or introduced, endemic or not). The CVPRG is generated automatically from the Guinea Collections Database and the Guinea Names Backbone Database, both developed and maintained at the Royal Botanic Gardens, Kew, in collaboration with the staff of the National Herbarium of Guinea. A total of 3505 indigenous vascular plant species are reported of which 3328 are flowering plants (angiosperms); this represents a 26% increase in known indigenous angiosperms since the last floristic overview. Intended as a reference for scientists documenting the diversity and distribution of the Guinea flora, the CVPRG will also inform those seeking to safeguard the rich plant diversity of Guinea and the societal, ecological and economic benefits accruing from these biological resources.

SummaryWe revise and update the records of strict and near-endemic species of Mt Kupe, Cameroon respectively from 31 strict endemics in 2004, to 25 today, and with near-endemic species 30, unchanged in number but with turnover. The changes result from new collections, discoveries and taxonomic changes in the last 16 years. While 15 of the provisionally named putative endemic species have now been formally published, a further 18 have not. The majority of the 30 near-endemic species (18) are shared with the adjacent Bakossi Mts, far exceeding the numbers shared with the more distant Mt Etinde-Mt Cameroon, Rumpi Hills and Ebo forest areas (sharing three near-endemic species each with Mt Kupe). We test the hypothesis that a further one of the provisionally named putative Mt Kupe species,Veprissp. 1 from submontane forest near the summit, is indeed new to science. We compare it morphologically with the two other bicarpellate high altitude Cameroon Highland tree speciesV. montisbambutensisOnana andV. baliCheek, concluding that it is a new undescribed species here named asVepris zapfackii. The new species is illustrated and its conservation status assessed as Critically Endangered using the 2012 IUCN standard, due to habitat clearance from agricultural pressures at its sole location which is unprotected.Vepris zapfackiiandV. baliappear unique in African trifoliolate species of the genus in having opposite leaves.Vepris zapfackiidiffers in having hairy petiolules and midribs and petiolules with the blade decurrent distally, narrowing towards a winged-canaliculate base (vs glabrous and petiolule long, terete), and sparsely golden hairy pistillodes and a glabrous calyx (vs densely black hairy pistillodes, and sepals hairy).

SummaryFour species of Rinorea are described as new to science; all four species are endemic to evergreen rain forest in Cameroon. Rinorea villiersii Achound. and R. amietii Achound are placed in Rinorea [unranked] Crassiflorae M.Brandt, while, R. dewildei Achound. and R. faurei Achound. fall in Rinorea [unranked] Dentatae Engl. The first species appears to be endemic to the Solé Forest Reserve northeast of Yabassi in Littoral Region. The second and the third species are found mainly in Littoral and South Regions, R. amietii extending to South West Region and R. dewildei extending to Central Region. The fourth species, R. faurei is an endemic of the Santchou Forest Reserve at the foot of Dschang Plateau in West Region. The taxonomic affinities of the four species are discussed, illustrations and a distribution map are provided, and their conservation status is assessed. All four species are threatened with extinction according to the 2012 IUCN categories and criteria.

SummaryA new species to science of evergreen forest shrub, Kupeantha yabassi M.G.Alvarez & Cheek (Coffeeae - Rubiaceae), is described, illustrated and compared morphologically with the closely similar species K. pentamera. Restricted so far to a single site in evergreen lowland forest near the Ebo Forest, Yabassi, Littoral Region, Cameroon, this species is Critically Endangered using the IUCN 2012 standard due to habitat clearance driven mainly by agriculture, adding to the growing list of threatened species resulting from anthropogenic pressure on Cameroon forests. A revised key to the six species of Kupeantha is presented. Two distinct geographical and ecological species groupings within the genus are identified and discussed. Notes are given on other narrowly endemic and threatened species in the Ebo Forest area, a threatened centre of diversity important for conservation in the Littoral Region.

SummaryThis paper reports a further discovery of a new endemic threatened species to science in the context of botanical surveys in the lowland coastal forests of Mount Cameroon in the Cross River-Sanaga interval of west-central Africa. These studies now focus on species discovery and conservation through the Tropical Important Plant Areas programme. New species to science continue to be discovered from Mt Cameroon. Most of these species are rare, highly localised, and threatened by habitat destruction, increasing the justification for improved conservation management of surviving habitat. Drypetes burnleyae is placed in and keyed out in Drypetes sect. Stipulares, a group mostly confined to Lower Guinea, here adjusted to accommodate nine species. The conservation status of Drypetes burnleyae is assessed as Endangered (EN B1+2ab(iii)) according to the 2012 criteria of the International Union for the Conservation of Nature. An updated overview of the plant endemics of Mt Cameroon is presented.

SummaryThe spectacular new species with horticultural potential described in this paper, Hibiscus hareyae L.A.J.Thomson & Cheek, was identified during an assessment of online digitised botanical specimens of H. schizopetalus (Dyer) Hook.f. as part of a review of species in Hibiscus sect. Lilibiscus Hochr. A short updated description and delimitation of the horticulturally important sect. Lilibiscus is presented. Flowering and fruiting specimens of Hibiscus hareyae are readily distinguished from H. schizopetalus by their short (0.4 – 2 (– 4.5) cm long, non-articulated peduncle-pedicels vs (6 –) 8 – 11 (– 14) cm long, articulated peduncle-pedicels, and larger, broader epicalyx bracts (1.5 – 4 × 1 – 1.2 mm vs 0.6 – 1.5 × 0.1 – 0.3 (– 0.5) mm), the epicalyx forming a shallow cup 0.5 – 1 × 2 – 3 mm vs bracts appearing free. The absence of an articulation of the peduncle-pedicel of H. hareyae is unique within sect. Lilibiscus. The species is also well-marked from H. schizopetalus by other morphological differences in corolla and foliage, and in ecology and geography. Hibiscus hareyae has a restricted natural distribution as an element in deciduous coastal thicket, usually on coral rag formations, sometimes in or near mangrove, in Lindi Province, southern Tanzania. It ranges from the Indian Ocean coast to as much as 20 km inland, from about 8.5oS to 10oS (c. 140 × 20 km) and is assessed as Vulnerable (VU B2ab(iii)). Hibiscus hareyae has high ornamental potential but is unknown in cultivation.

SummaryThree new species of Inversodicraea (Podostemaceae), I. senei from the Memv’ele falls of the Ntem River, Cameroon, I. tanzaniensis from the Ruhudji River near Lupembe, Southern Highlands, Tanzania, and I. botswana from the Kasane rapids on the Chobe River, Botswana, are described and illustrated. All three species are known from single sites. All three are assessed as Critically Endangered using the IUCN standard. With 35 species, Inversodicraea is the most species-diverse genus of Podostemaceae in continental Africa, to which it is endemic. Four species of Inversodicraea are now known to be sympatric and point endemics at Memv’ele Falls in Cameroon where a hydro-electric dam is being constructed, threatening them with global extinction. Equally, I. tanzaniensis is threatened by proposed hydro-electric projects in Tanzania. In contrast, I. botswana is threatened by sewage discharge and also by bridge construction.

SummaryVepris verdoorniana(Rutaceae) has long been regarded as a widespread and variable species occurring from Guinea to Gabon. Recent evidence has shown that the original material from the type locality in Cameroon consists of two different species,V. verdoornianain the strict sense, endemic to Lower Guinea (Cameroon, Gabon and C.A.R. in W-C Africa) andV. letouzeyiOnana, which was thought to occur from Guinea to Cameroon. In this paper we show that the West African (Upper Guinea) material previously referred to asV. letouzeyi/V. verdoornianais separate morphologically from that in Cameroon (Lower Guinea). In fact the West African material referred to comprises two distinct species, here described asV. occidentalisCheek & Onana (Guinea to Ghana, but probably extending to Benin) a tree of lowland marginal dry evergreen and semi-deciduous forest, andV. ferCheek, a species restricted to four mainly lower submontane forest locations on iron substrates in Liberia and Sierra Leone (also Upper Guinea).Vepris occidentalisis here assessed as Least Concern due to its wide range and high frequency, whilstV. feris assessed as Endangered due to the low number of locations and threats from iron ore mining projects. Both new species are illustrated and mapped.

Summary Cola cheringoma is described from the limestone gorge forest of the Cheringoma Plateau in Sofala Province of Central Mozambique. Tentatively treated previously as C. clavata Mast., it differs in being restricted to limestone substrate, the leaves drying white-green below (not on sandy soils, drying dark grey-brown). The tepal number of female flowers is 5 (not (5 –) 6), staminode number 5 (not 8), and the indumentum of the outer perianth covers only 50 – 60% of the surface with two distinct hair classes (not 100% coverage with a single hair type). The species is assessed as EN B2ab(iii) using the IUCN 2012 standard due to threats from the low number of locations, quarrying, and habitat modification. The Cola species growing in forest on limestone in tropical Africa are mapped and reviewed with respect to their status as obligate or facultative calcicoles, and with respect to their probable evolutionary origin. Based on morphological characters, adaptation to limestone habitats has probably occurred at least four times in the genus. Forests on limestone are rare and threatened in tropical Africa: only thirteen locations are known with certainty: these occur in Kenya (10 locations), Tanzania (2 locations) and Mozambique (1 location).

Species delineation and taxonomic status of three species of Coleus Lour. from the Guinean Highlands, West Africa, are discussed in the context of related taxa. A new species, C. ferricola Phillipson, O.Hooper & A.J.Paton, is found on iron-rich substrates. The related C. splendidus A.Chev. is recognised as a distinct species with C. djalonensis A.Chev. and C. peulhorum A.Chev. var. violacea A.Chev. placed in synonymy. The new combination, Coleus lateriticola (A.Chev.) Phillipson, O.Hooper & A.J.Paton, based on Solenostemon lateriticola A.Chev., but frequently treated at subspecific rank under Plectranthus monostachyus (P.Beauv.) B.J.Pollard, is established. These taxa are described and discussed, and distribution data, illustrations and IUCN Red List assessments are also provided.

Cola dorrii Cheek sp. nov. is described from Maputaland Sand and Northern Coastal Forest types in KwaZulu-Natal of South Africa. Formerly treated as Cola greenwayi Brenan, it differs in much shorter leaf-blades and petioles, and in the fruitlets which are stipitate, with apices that are rounded and forward-facing. The indumentum has stellate hairs which are soft, with sinuate arms, rather than subscabrid with stiff arms. The species is assessed as Vulnerable using the IUCN 2012 standard due to habitat modification and loss due to humans, elephants and due to the invasive shrub Chromolaena odorata.

Mesanthemum prescottianum is a West African species occurring in the uplands extending from Guinea to Ivory Coast. Variation within the species is discussed and the synonym M. tuberosum Lecomte is raised to specific status. The conservation status of the first species is assessed using the IUCN 2012 standard as Least Concern, and the second as Vulnerable. Lectotypes are selected for both names. The type location of M. prescottianum, claimed to be Brazil, is shown to be an error.

Warneckea ngutiensis R. D. Stone sp. nov. (Melastomataceae-Olisbeoideae) is described from near Nguti in SW Region, Cameroon. Unique in section Strychnoides in having only a vestigial staminal oil gland, this rainforest shrub is Critically Endangered due to an oil palm plantation project.

Ledermanniella yiben Cheek is described from the Seli (Rokel) river bed at a single rapid to be flooded by the proposed Yiben hydroelectric dam and reservoir in Sierra Leone. It is assessed as Critically Endangered using the IUCN categories and criteria. The species appears to be unique among African Podostemaceae in bearing dimorphic shoots having either cupuliform or short ribbon-like leaves.

Inversodicraea, shown by previous workers to merit resurrection, is restored here, to include all those species previously included in Ledermanniella subg. Phyllosma. The final seven species remaining in subg. Phyllosma are formally transferred to Inversodicraea as I. mortonii, I. gabonensis, I. boumiensis, I. harrisii, I. paulsitae, I. torrei and I. thollonii. A new species from the submontane forest of Mt Ziama, in Guinea-Conakry is formally described as I. pepehabai. Similar to I. adamesii, it is assessed as Endangered according to the IUCN 2012 standard.

Allophylus samoritourei from the lowland and submontane forests of the Loma-Man highlands in Guinea-Conakry and Liberia, Africa and Allophylus bertoua from lowland eastern Cameroon are described and illustrated as part of a synoptic revision of the four spiny African species of Allophylus. IUCN conservation assessments are given for all species. The phenomena of androgynophores and of spiny structures in the Sapindaceae, and the possibility of monophyly of spiny Allophylus are discussed.

The name Leptonychia kamerunensis Engl. & K. Krause is resurrected for an understorey tree of submontane forest in the Cameroon Highlands. L. subtomentosa K. Schum. is resurrected for a tree of the hilly semi-deciduous forests around Yaounde in Central Province, Cameroon. L. moyesiae Cheek, a shrub of lowland coastal evergreen forest of SE Nigeria, SW Province Cameroon and Bioko, is newly described. The taxonomic affinities and conservation status of these three species are assessed.

Calophyllum africanum Cheek & Q. Luke is described and illustrated from Mali, in that part close to the Fouta Djalon of Guinea. Plant species present in its gallery forest habitat are listed in detail. Threatened by gold and uranium mining activities, C. africanum is here assessed as Critically Endangered according to the categories and criteria of IUCN. This is the first native Calophyllum known from continental Africa apart from the indo-pacific littoral C. inophyllum. The affinities of C. africanum appear to lie with the Neotropics and it is most similar to the Caribbean species C. antillanum.

Psychotria samoritourei Cheek is described from the submontane forests of the Loma-Man highlands in Upper Guinea, West Africa. It is the sixth known lianescent African species of its genus. The distinguishing characters and taxonomic affinities of the species are analysed and its conservation status is assessed. An overview of the Loma-Man highlands and their forests is presented.

Ardisia ebo Cheek sp. nov. (Myrsinaceae) is described as a creeping African subshrub. Its taxonomic affinities are discussed and its conservation status assessed using the IUCN Red List Categories and Criteria (2001) as Endangered.

Striga magnibracteata Eb. Fisch. & I. Darbysh. is newly described from the Guinean savannas of eastern Guinee and southwestern Mali. Its affinity to S. klingii (Engl.) Skan, S. dalzielii Hutch. and S. macrantha (Benth.) Benth. is discussed and its conservation status is assessed.

Five species of achlorophyllous heteromycotrophs, better known as saprophytes, are here reported from Guinea for the first time, raising the national total to six. They include a new species, Gymnosiphon samoritoureanus Cheek, which is described and illustrated, and assessed as Vulnerable using IUCN (2001).

Deinbollia oreophila Cheek (Sapindaceae) is described from the submontane forests of the Cameroon Highlands, extending to the Obudu Plateau of Nigeria. It is unusual in being the only submontane species of the genus in West and Central Africa, and in being glabrous, with bright white raised lenticels. Its morphological variation and its conservation status are assessed.

Oricia lecomteana Pierre (Rutaceae), a rare and threatened shrub or tree of coastal lowland and lower submontane evergreen forest from Southeast Nigeria to Congo-Brazzaville, is transferred to Vepris A. Juss. as Vepris lecomteana (Pierre) Cheek & T. Heller and its taxonomic, geographic and conservation status is assessed.

Allophylus conraui Gilg ex Radlk. as treated in the Flora of West Tropical Africa is reassessed and shown to comprise two distinct taxa, one of which, a spiny shrub or small tree of upper submontane forest in Cameroon and Nigeria, is described as Allophylus ujori Cheek. The second taxon, a lowland to lower submontane spineless small shrub, of Cameroon is redescribed as Allophylus conraui and neotypified. The affinities and conservation status of both these threatened species are discussed. Both taxa are illustrated.

A key is presented to the Nepenthes group Montanae in Peninsular Malaysia, Thailand and Cambodia. Nepenthes bokor Cheek is described from Cambodia and Nepenthes thai Cheek from peninsular Thailand. The affinities of both taxa are discussed and their conservation status assessed.

Described and illustrated is Warneckea austro-occidentalis R. D. Stone, an endemic of tropical forests in Cameroon’s South West Province and adjacent Nigeria. The name W. mangrovensis (Jacq.-Fel.) R. D. Stone is also proposed at species level for the taxon originally described as W. fascicularis var. mangrovensis Jacq.-Fel. An IUCN (2001) status of endangered is assigned for both W. austro-occidentalis and W. mangrovensis.

Seven new names at species rank are proposed in Memecylon sect. Afzeliana Jacq.-Fel., a group of forest shrubs and small trees confined to Guineo-Congolian Africa. The group is centred in Cameroon, where 17 of the 20 species occur. A new flower type, the “star-flower” in Memecylon is revealed, and its taxonomic and ecological importance discussed. Three new, locally endemic species from the South West Province of Cameroon are described, mapped and illustrated: M. kupeanum R. D. Stone, Ghogue & Cheek, M. bakossiense R. D. Stone, Ghogue & Cheek, and M. rheophyticum R. D. Stone, Ghogue & Cheek. Two new names, M. accedens R. D. Stone, Ghogue & Cheek and M. hyleastrum R. D. Stone & Ghogue and one new combination, M. mamfeanum (Jacq.-Fel.) R. D. Stone, Ghogue & Cheek are provided at species level for three taxa originally proposed as varieties of M. afzelii G. Don. The taxon M. arcuatomarginatum var. simulans Jacq.-Fel. is also elevated to species status, as M. simulans (Jacq.-Fel.) R. D. Stone & Ghogue. Conservation assessments are provided for all the newly named taxa. A key is provided to the species of Memecylon sect. Afzeliana.

Psychotria kupensis Cheek is described as a new species in Psychotria sect. Confertiflorae Hiern. Attention is drawn to its monopodial, dwarf, litter-gathering and adventitious root-forming habit and to its anomalous stipules. The species appears to be endemic to the submontane evergeen forest of Mt Kupe in Cameroon. Its conservation status is assessed.

Two West-Central African species of Hannoa Planch. are formally resurrected in the genus Quassia L. and the necessary new names provided.

We show that two distinct species have been confused under the name of Tarenna hutchinsonii Bremek. T. hutchinsonii itself appears to be confined to its type location in Sierra Leone (where it is presumed extinct) and to several newly discovered locations in Guinea and Liberia. It has been assessed as Critically Endangered using the 2012 IUCN standard. Material from Ghana and Ivory Coast previously ascribed to T. hutchinsonii is here described as T. agnata Cheek & Lopez Poveda, and assessed as Critically Endangered, although it may well already be globally extinct.

Ledermanniella lunda Cheek sp. nov. is described and illustrated from Lunda Norte Province of Angola. Threatened by diamond mining and a hydro-electric dam, it is here assessed as Critically Endangered according to the categories and criteria of IUCN.

Korupodendron songweanum is described as the second genus of Vochysiaceae from Africa. Its classification, biogeography, conservation status, and local name and uses are discussed.

The unispecific Fijian genus Pimia Seem. (Sterculiaceae) has long been considered to be related to genera that are now included in the Byttneriaceae (also known as Malvaceae-Byttnerioideae). Morphological characters, however, indicate that Pimia is a mixture of Commersonia J. R. Forst. & G. Forst. (Byttneriaceae) and Diospyros L. (Ebenaceae). The name of the sole species, P. rhamnoides Seem., is lectotypified with an element that is determined to be C. bartramia (L.) Merr. and thus Pimia becomes a synonym of Commersonia. An epitype for P. rhamnoides is also selected because the lectotype now lacks flowers, which were an important element of the protologue.

Froelichia (Amaranthaceae) is reported from the Sahel of Senegal for the first time. This is a new generic record for Africa and is a cause for concern since the genus is known to be an invasive weed in other countries with warm climates and sandy substrates. The difficulties caused by this taxon are summarised and control measures are suggested.

Coleochloa domensis Muasya & D. A. Simpson, a new species of epiphytic sedge from submontane forest in Cameroon, is described and illustrated. Its conservation status is assessed as Critically Endangered (CR).

It is shown that the single record of the genus Brucea J. F. Mill. (Simaroubaceae) from Yemen in the Arabian Peninsula (Wood 2886), identified as Brucea antidysenterica J. F. Mill., is based on a misidentification. The specimen is actually Polyscias fulva (Hiern) Harms in the Araliaceae, a genus and species not previously recorded from the Peninsula although a common pioneer tree of submontane forest in neighbouring continental Africa.