KEW BULLETIN (2018) 73:12 DOI 10.1007/S12225-018-9739-4 ISSN: 0075-5974 (print) ISSN: 1874-933X (electronic) A revised key to the Warneckea species of Cameroon, and description of Warneckea ngutiensis (Melastomataceae-Olisbeoideae), a new Critically Endangered rainforest shrub Robert Douglas Stone1 & Martin Cheek2 Summary. 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. Key Words. Banyang Mbo, conservation, Earthwatch, extinction, Herakles, oil palm plantation. Introduction The genus Warneckea Gilg is closely allied with and has previously been united with the genus Memecylon L., but is phylogenetically distinct and generally distinguished by its conspicuously 3-nerved leaf-blades (Stone 2006; Stone & Andreasen 2010). On-going studies have steadily increased the number of known species of Warneckea, with the most recent additions to the genus for Cameroon being the range-restricted and threatened species W. austro-occidentalis R. D. Stone and W. mangrovensis (Jacq.-Fél.) R. D. Stone (Stone et al. 2009). With these additions there were 12 species of Warneckea recognised by Onana (2011) as occurring in Cameroon. The present investigation concerns an unusual Warneckea (represented by the specimen Pollard 552) that was collected in November 2000 during a two-week botanical survey and training exercise in the forest on the southern boundary of the then Banyang Mbo Wildlife Sanctuary, located near the town of Nguti in Cameroon’s South-West Region. At the time of this field survey, Banyang Mbo was co-managed by the Wildlife Conservation Society (WCS) and the Ministry of Environment and Forest (MINEF). The survey was conducted as part of the Earthwatch-Darwin Initiative supported “Plant Diversity of western Cameroon” project led by botanists from Royal Botanic Gardens, Kew and the National Herbarium of Cameroon. The methodology used is detailed in Cheek & Cable (1997). Numerous herbarium specimens were collected with the intention that they would form the nucleus of data for a 'Conservation Checklist' of Banyang Mbo, in the series that began with Mt Cameroon (Cable & Cheek 1998) and continued with Kupe-Bakossi (Cheek et al. 2004), Bali-Ngemba (Harvey et al. 2004), Mefou (Cheek et al. 2011) and Lebialem Highlands (Harvey et al. 2010). Pollard 552 was later identified by one of us (RDS) as a member of the main section present in W-C Africa, Warneckea sect. Strychnoides (Engl.) Jacq.-Fél. ex R. D. Stone (Stone & Andreasen 2010). However, uniquely in this group, among other features, the anther connectives of the Nguti taxon have only a vestigial oil gland, a feature generally important at the species-group or subgeneric level throughout the subfamily Olisbeoideae. Accordingly, the species represented by Pollard 552 is here described as Warneckea ngutiensis sp. nov. The lowland evergreen forests of SW Cameroon have proved to be rich in new species of plants, from herbs, shrubs and lianas to canopy trees. Among those published from the surveys discussed above, from the forests adjoining those at Nguti, mainly from the Bakossi area immediately adjacent to the South, are: Coffea montekupensis Stoff. (Stoffelen et al. 1997), Diospyros kupensis Gosline (Gosline & Cheek 1998), Ancistrocladus grandifolius Cheek (2000), Ledermanniella onanae Cheek (2003), Memecylon kupeanum R. D. Stone, Ghogue & Cheek and M. bakossiense R. D. Stone, Ghogue & Cheek (Stone et al. 2008). To date, two new genera have also been discovered, Kupea Cheek & S. A. Williams (Cheek et al. 2003) and Korupodendron Litt & Cheek (2002). However, all of these taxa are threatened with extinction due to habitat clearance, mainly for agriculture (Onana & Cheek 2011). Efforts are now being made to delimit the highest priority areas in Cameroon for plant conservation as Tropical Important Plant Areas (TIPAs) using the revised IPA criteria set out in Darbyshire et al. (2017). This is essential if more narrowly endemic species are not to become extinct in Cameroon as has Oxygyne triandra Schltr. (Cheek & Onana 2011). Accepted for publication 14 February 2018. 1 School of Life Sciences, University of KwaZulu-Natal, Private Bag X01, Pietermaritzburg, 3209, South Africa. e-mail: StoneRD@ukzn.ac.za 2 Herbarium, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AE, UK. © The Board of Trustees of the Royal Botanic Gardens, Kew, 2018 12 Page 2 of 6 KEW BULLETIN (2018) 73:12 Revised key to the species of Warneckea in Cameroon 1. Leaf bases rounded and narrowly cordate above the petiole; leaf-blades with principal nerves prominent on both surfaces; inflorescences sessile or short-pedunculate; bracts persistent, imbricate-decussate; flowers sessile or short-pedicellate (Warneckea sect. Guineenses R. D. Stone) . . . . . . . . . . . . . W. mangrovensis (Jacq.-Fél.) R. D. Stone Leaf bases either rounded, cordate or cuneate (not rounded and narrowly cordate); leaf-blades with principal nerves impressed on the upper surface, prominent on the lower; inflorescences conspicuously pedunculate, in some cases with well-developed secondary axes (rarely contracted and subsessile); bracts ± rapidly deciduous; flowers distinctly pedicellate (rarely subsessile); (Warneckea sect. Strychnoides (Engl.) Jacq.-Fél. ex R. D. Stone) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Inflorescences mainly below the leaves, fascicled at the swollen nodes of older branchlets (in W. memecyloides borne in the lower leaf axils and at recently defoliated nodes); flowers distinctly pedicellate . . . . . . . . . . 3 Inflorescences mainly in the leaf-axils (in W. cinnamomoides and W. fosteri also at the recently defoliated nodes); flowers in some species short-pedicellate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3. Leaf-blades elliptic, 10 − 20 cm long × 4 − 9 cm wide, cuneate at base; inflorescences subsessile or on peduncles 2 − 7 mm long; fruits ± globose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Leaf-blades broadly elliptic to ovate, obovate, oblanceolate or suborbicular, mostly 12 − 32 cm long × 7 − 12 cm wide, rounded to cordate or broadly cuneate at base; inflorescences on peduncles 6 − 30 (− 40) mm long; fruits ellipsoid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4. Leaf-blades c. 10 cm long × 4 cm wide; inflorescences densely fascicled, on peduncles 2 − 7 mm long . . . . . . . . . . . . . . . . . . . . . . . W. sapinii sensu Jacques-Félix (1983), but not as to type Leaf-blades up to 20 cm long × 9 cm wide; inflorescences subsessile . . . . . . . . . . . . . . . . . . . . . . . . W. wildeana Jacq.-Fél. 5. Leaf-blades ovate to broadly elliptic or suborbicular, 12 − 18 cm long × 7 − 10 cm wide, rounded to shallowly cordate at base; inflorescences borne in the lower leaf axils and at recently defoliated nodes; peduncles 6 – 10 mm long; fruits 10 mm long × 6 mm wide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . W. memecyloides (Benth.) Jacq.-Fél. Leaf-blades larger, or if of similar dimensions then broadly cuneate to rounded at base (not cordate); inflorescences fascicled at the swollen nodes of older branchlets; peduncles mostly c. 20 – 30 mm long; fruits as above or larger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 6. Leaf-blades ± oblanceolate, 20 – 32 cm long × 9 – 12 cm wide, narrowly cordate-auriculate at base; petioles 2 – 4 mm long; petals blue-violet; fruits 10 mm long × 8 mm wide . . . . . . . . . . . . . . . . . . . . W. pulcherrima (Gilg) Jacq.-Fél. Leaf-blades broadly ovate to broadly elliptic or broadly obovate, 12 – 19 cm long × 7.5 – 10 cm wide, broadly cuneate to rounded at base; petioles 7 – 10 mm long; petals white; fruits 15 – 16 mm long × 10 – 11 mm wide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . W. austro-occidentalis R. D. Stone 7. Leaves apparently 1-nerved (the lateral pair of nerves submarginal, scarcely visible on the upper surface, forming a series of shallow arches from the base between the junctions with the transverse veins); inflorescences sessile to subsessile . . . . . . . . . . . . . . . . . . . . . . . . . . . W. bebaiensis (Gilg ex Engl.) Jacq.-Fél. Leaves distinctly 3-nerved (the lateral pair of nerves clearly visible and percurrent from the base to the apex); inflorescences as above or on peduncles to 10 mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 8. Inflorescences on peduncles 2 – 10 mm long, directly umbelliform or if branched then each secondary axis ± unbranched and 1 to 3-flowered; flowering pedicels slender, 4 – 10 mm long . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Inflorescences compact, borne on peduncles up to 6 mm long or subsessile and reduced to 1 to 3 flowers; flowers ± sessile or on pedicels 1 – 4 mm long . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 9. Leaves subcoriaceous; inflorescences axillary and sometimes terminal; fruits globose . . W. jasminoides (Gilg) Jacq.-Fél. Leaves coriaceous; inflorescences in the lower leaf-axils and at the recently defoliated nodes; fruits globose or ellipsoid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 10. Leaf-blades 8 − 14 cm long × 4 − 7 cm wide; fruits ellipsoid, 10 mm long × 6 mm wide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . W. cinnamomoides (G. Don) Jacq.-Fél. Leaf-blades 6 − 8 cm long × 3 − 4 cm wide; fruits globose, 6 × 6 mm . . . . . . . . . W. fosteri (Hutch. & Dalziel) Jacq.-Fél. 11. Young branchlets robust, subquadrangular; leaf-blades 10 − 17 cm long × 5 − 8 cm wide; fruits globose, 10 – 15 mm in diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . W. reygaertii sensu Jacques-Félix (1983) Young branchlets acutely quadrangular to narrowly quadrangular-alate; leaf-blades 5 − 13.5 (− 18) cm long × 3 − 6.5 (− 7) cm wide; fruits ellipsoid-oblong to ovoid or pyriform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 12. Inflorescences on peduncles 3 – 6 mm long, shortly branched, 5 – 7-flowered, 1 – 1.5 cm long in total; flowers on pedicels 1 – 2 mm long . . . . . . . . . . . . . . . . . . . . . . . . W. yangambensis (A. Fern. & R. Fern.) Jacq.-Fél. Inflorescences sessile or on peduncles to 2 mm long, unbranched, 1 – 3-flowered, 0.5 cm long in total; flowers sessile or on pedicels to 2 mm long . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 © The Board of Trustees of the Royal Botanic Gardens, Kew, 2018 KEW BULLETIN (2018) 73:12 Page 3 of 6 12 13. Anther connective gland conspicuous, elliptic in outline . . . . . . . . . . . . . . . . . . . . W. membranifolia (Hook. f.) Jacq.-Fél. Anther connective gland vestigial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . W. ngutiensis R. D. Stone Warneckea ngutiensis R. D. Stone sp. nov. Type: Cameroon, South West Province, Nguti region, towards river Lowoa near edge of Banyang Mbo Wildlife Sanctuary, 5°20.23'N, 9°28.41'E, alt. 250 m, forest understory, fls. & fr., 28 Nov. 2000, Pollard 552 (holotype K [K000460176]; isotype YA). http://www.ipni.org/urn:lsid:ipni.org:names:77175882-1 Evergreen understorey shrub to 1.5 m tall. Branchlets slender, the youngest quadrangular in cross section and narrowly alate becoming terete with age; internodes 3 – 4 (– 4.7) cm long. Leaves on petioles 3.5 – 4 mm long, the petioles channelled on the adaxial side. Blades subcoriaceous, dark green and shining on the upper surface, paler beneath, elliptic in outline, up to 13.5 cm long and 6.5 cm wide, base broadly cuneate, acuminate at apex, the acumen slender and 1.5 – 2.5 cm long; midnerve and principal lateral nerves impressed on the upper surface, prominent on the lower, the lateral nerves diverging from the midnerve at the base of the blade, curvilinear except near the leaf apex where forming weak arches between the junctions with the transverse veins; secondary lateral nerves 1 pair, much thinner than the principal laterals, intramarginal and weakly arched for their entire length; transverse veins 8 – 12 pairs, of about the same thickness as the secondary laterals, somewhat prominent on the lower surface along with the conspicuous network of smaller venules. Inflorescence sessile, 3-flowered, borne at the thickened nodes of older branches below the existing leaves; bracts and bracteoles 1 – 1.5 mm long, lance-ovate, cucullate. Flowers sessile or nearly so (if pedicels present then very short and concealed by the subtending bracts and bracteoles); hypantho-calyx obconic, 2 × 2 mm, the margin spreading and distinctly lobed, the lobes broadly triangular. Petals violet, narrowly spatulate – unguiculate, 2 mm long and 0.75 – 1 mm wide, at anthesis spreading to slightly recurved. Stamens well exserted on slender violetcoloured filaments 4 mm long; anthers 1 mm long, the connective yellow, ± straight to slightly incurved dorsally, the oil-gland vestigial and appearing as a dark discolouration between the middle and the extremity of the connective. Style slender, 5 mm long. Fruit dark purple at maturity, 8 mm long and 5 mm wide, crowned by the persistent calyx. Fig. 1. RECOGNITION. Differs from other species of Warneckea sect. Strychnoides by the combination of inflorescences sessile, flowering pedicels very short, and staminal oilgland vestigial (not conspicuously present on the dorsal side of the anther connective). SPECIMENS EXAMINED. CAMEROON. South West Province, Nguti region, towards river Lowoa near edge of Banyang Mbo Wildlife Sanctuary, 5°20.23'N, 9°28.41'E, alt. 250 m, forest understory, fls. & fr., 28 Nov. 2000, Pollard 552 (holotype K [K000460176]; isotype YA). HABITAT & ECOLOGY. Lowland evergreen forest; 250 m alt. CONSERVATION. Warneckea ngutiensis is assessed here as Critically Endangered CR B1 + B2ab(iii) + D using the IUCN (2012) criteria. This is because it is known from a single location just to the south of the former Banyang Mbo Wildlife Sanctuary (since downrated in protected status) near the town of Nguti. Many memecyloid species are both restricted in their range and infrequent within it (Cheek pp. 212 – 222 in Onana & Cheek 2011), and this is supposed by us to be the case with W. ngutiensis. This is because, in 2 weeks’ botanising by numerous botanists at this location in 2000, only one gathering was made of this species. Further subsequent botanical surveys from the same base near Nguti by botanists from the University of Rostok, Germany led by Prof. Stefan Porembski (pers. comm. to Cheek) and Prof. Bonaventure Sonké of the École Normale Supérieure, University of Yaoundé (pers. comm. to Cheek) have similarly not produced any additional records of the species so far as is known. The only known site for Warneckea ngutiensis is within the boundary of the area proposed as an oil palm plantation by the U.S.A.-based company, Herakles (http://www.greenpeace.org/usa/wp-content/uploads/ legacy/Global/usa/planet3/PDFs/ HeraklesCrimeFile.pdf., and https://www.google.co.uk/ ?gfe_rd=cr&ei=JaTuVdz2FYnj8weqyIKIBQ&gws_rd=ssl#q=herakles+oil+palm+plantation,+cameroon both downloaded 8 Sept. 2015). Although this operation was reported as suspended in 2013 (http:// www.greenpeace.org/international/en/news/Blogs/ makingwaves/herakles-cameroon-palm-oil-project-startsto-/blog/45259/ downloaded 9 Sept. 2015), there are concerns that it will be resurrected in the near future since Herakles has continued its activities on the ground (https://www.grain.org/article/entries/5037-communities-lose-out-to-oil-palm-plantations, downloaded 9 Sept. 2015). Therefore, there is every chance that all known individuals of the species will become extinct when clearing proceeds for the establishment of the plantation. It is perfectly possible that the species also extends to the © The Board of Trustees of the Royal Botanic Gardens, Kew, 2018 12 Page 4 of 6 KEW BULLETIN (2018) 73:12 Fig. 1. Warneckea ngutiensis. A habit, flowering branch; B detail of stem apex, leaf base and internode; C transverse section of stem showing four wings — from B; D inflorescence, showing bracts and bracteoles; E single flower, detail of D; F flower cut open longitudinally and flattened to show insertion of filaments and petals; G bract, adaxial surface, showing colleters-hairs; H petals; J – L anther with expanded connective, oil gland absent, J outer surface, K inner surface, L side view; M fruit. All from Pollard 552. DRAWN BY ANDREW BROWN. © The Board of Trustees of the Royal Botanic Gardens, Kew, 2018 KEW BULLETIN (2018) 73:12 north into the Banyang Mbo reserve where it might have the prospect of protection. Yet equally it might extend south and west of Nguti into the main part of the area designated for plantation by Herakles. This area remains relatively unsurveyed for plants, although it occurs within the area of Tropical Africa with the highest density of wild plant species, which occurs in SW Region Cameroon (Cheek et al. 2001). Even if a broad buffer area were created outside the boundary of Banyang Mbo, there is a risk that farmers displaced by the future plantation project will take up land within it and so threaten the only known locality of Warneckea ngutiensis. For these reasons we consider the only known location for Warneckea ngutiensis to be highly threatened, and the extent of occurrence and area of occupancy of the species to be 4 km2, adopting the preferred IUCN (2012) 4 km2 grid cell. Warneckea ngutiensis is also threatened because of the low number of individuals recorded: no more than five were thought to have been seen by Pollard (pers. comm. to Cheek). In the Red Data Book of the Plants of Cameroon (Onana & Cheek 2011), ‘Warneckea ngutiensis ined.’ was first mentioned and considered to be Critically Endangered. However, since it had not been published, its threatened status could not be accepted by IUCN at that time. ETYMOLOGY. Named for the town of Nguti, the closest settlement to the type location. Discussion Warneckea ngutiensis evidently belongs in W. sect. Strychnoides, a monophyletic group of c. 24 species distributed in Guinean-Congolian Africa (Stone & Andreasen 2010). Amongst the species of this section, the inflorescence dimensions are quite variable, as are the size and position of the anther gland. On the one hand there is a group of closely related species with long peduncles and distinctly pedicellate flowers, e.g. W. pulcherrima, W. austro-occidentalis and W. bequaertii (De Wild.) Jacq.-Fél. On the other hand there are several species with inflorescences sessile or subsessile and with flowering pedicels also very short, e.g. W. membranifolia, W. reygaertii, W. yangambensis, and W. gilletii (De Wild.) Jacq.-Fél. In terms of the anthergland, there are several species in sect. Strychnoides with the gland occupying 1=3 to 2=3 the length of the connective, while in other species it is positioned near the extremity of the connective, or even reduced and punctiform e.g. W. sapinii (De Wild. ) Jacq.-Fél. as per the description in Fl. Cameroun (Jacques-Félix 1983). Within Warneckea sect. Strychnoides, the new species W. ngutiensis seems closest to the above-mentioned group of four species with sessile or subsessile inflorescences and flowers. Of these there is only one species, W. membranifolia, in which both the Page 5 of 6 12 inflorescences and flowers can be fully subsessile as in W. ngutiensis. Warneckea membranifolia is widespread and common in intact evergreen forest in Cameroon, but is clearly distinguished by having anthers with a conspicuous oil-gland (vs gland vestigial and inconspicuous in W. ngutiensis). Acknowledgements The authors are grateful to the National Herbarium of Cameroon-IRAD-MINRESI for permission to collect specimens in Cameroon, to WCS Cameroon for accommodation in the Banyang Mbo Research Station, and to Earthwatch Europe for supporting the survey by sponsoring costs of the participants. The Darwin Initiative also supported elements of this survey. Janis Shillito typed the manuscript. Two anonymous reviewers are thanked for comments on an earlier version of the manuscript. References Cable, S. & Cheek, M. (1998). The Plants of Mt Cameroon. A Conservation Checklist. Royal Botanic Gardens, Kew. Cheek, M. (2000). A synoptic revision of Ancistrocladus (Ancistrocladaceae) in Africa, with a new species from western Cameroon. Kew Bull. 55: 871 – 882. ____ (2003). A new species of Ledermanniella (Podostemaceae) from western Cameroon. Kew Bull. 58: 733 – 737. ____ & Cable, S. (1997). Plant Inventory for conservation management: the Kew-Earthwatch programme in Western Cameroon, 1993 – 96. In: S. Doolan (ed.), African Rainforests and the Conservation of Biodiversity, pp. 29 – 38. Earthwatch Europe, Oxford. ____, Pollard, B. J., Darbyshire, I., Onana, J.-M. & Wild, C. (2004). The plants of Kupe, Mwanenguba and the Bakossi Mountains, Cameroon. A Conservation Checklist. Royal Botanic Gardens, Kew. ____, Harvey, Y. & Onana, J.-M. (2011). The Plants of Mefou Proposed National Park, Yaoundé, Cameroon. A Conservation Checklist. Royal Botanic Gardens, Kew. ____, Mackinder, B., Gosline, G., Onana, J.-M. & Achoundong, G. (2001). The phytogeography and flora of western Cameroon and the Cross River-Sanaga River interval. Syst. & Geogr. Pl. 71: 1097 – 1100. ____, Williams, S. & Etuge, M. (2003). Kupea martinetugei, a new genus and species of Triuridaceae from western Cameroon. Kew Bull. 58: 225 – 228. ____ & Onana, J.-M. (2011). Red Data Species in Cameroon, a Guide for Secondary School Teachers. Royal Botanic Gardens, Kew. Darbyshire, I., Anderson, S., Asatryan, A., Byfield, A., Cheek, M., Clubbe, C., Ghrabi, Z., Harris, T., Heatubun, C. D., Kalema, J., Magassouba, S., McCarthy, B., Milliken, W., de Montmollin, B., Nic © The Board of Trustees of the Royal Botanic Gardens, Kew, 2018 12 Page 6 of 6 Lughadha, E., Onana, J. M., Saıdou, D., Sarbu, A., Shrestha, K. & Radford, E. A. (2017). Important Plant Areas: revised selection criteria for a global approach to plant conservation. Biodivers. Conserv. 26: 1767 – 1800. https://doi.org/10.1007/s10531017-1336-6. Gosline, G. & Cheek, M. (1998). A new species of Diospyros (Ebenaceae) from Southwest Cameroon. Kew Bull. 53: 461 – 465. Harvey, Y., Pollard, B. J., Darbyshire, I., Onana, J.-M. & Cheek, M. (2004). The Plants of Bali Ngemba Forest Reserve. Cameroon. A Conservation Checklist, Royal Botanic Gardens, Kew. ____, Tchiengue, B. & Cheek, M. (2010). The Plants of the Lebialem Highlands, A Conservation Checklist. Royal Botanic Gardens, Kew. IUCN (2012). IUCN Red List Categories and Criteria: Version 3.1, Second edition. IUCN, Gland and Cambridge. Jacques-Félix, H. (1983). Mélastomatacées, In: B. Satabié & J.-F. Leroy (eds), Flore du Cameroun Vol. 24. Délégation Générale à la Recherche Scientifique et Technique, Yaoundé. Litt, A. & Cheek, M. (2002). Korupodendron songweanum, a new genus of Vochysiaceae from West-central Africa. Brittonia 54(1): 13 – 17. © The Board of Trustees of the Royal Botanic Gardens, Kew, 2018 KEW BULLETIN (2018) 73:12 Onana, J.-M. (2011). The Vascular Plants of Cameroon, A Taxonomic Checklist with IUCN Assessments. Flore Du Cameroun 39. Ministry of Scientific Research and Innovation, Yaoundé. ____ & Cheek, M. (2011). Red Data Book of the Flowering Plants of Cameroon. Royal Botanic Gardens, Kew. Stoffelen, P., Cheek, M., Bridson, D. & Robbrecht, E. (1997). A new species of Coffea (Rubiaceae) and notes on Mt Kupe (Cameroon). Kew Bull. 52: 989 – 994. Stone, R. D. (2006). Phylogeny of major lineages in Melastomataceae, subfamily Olisbeoideae: utility of nuclear glyceraldehyde 3-phosphate dehydrogenase (GapC) gene sequences. Syst. Bot. 31: 107 – 121. ____ & Andreasen, K. (2010). The Afro-Madagascan genus Warneckea (Melastomataceae): molecular systematics and revised infrageneric classification. Taxon 59: 83 – 92. ____, Ghogue J.-P. & Cheek, M. (2008). Revised treatment of Memecylon sect. Afzeliana (Melastomataceae-Olisbeoideae), including three new species from Cameroon. Kew Bull. 63: 227 – 241. ____, ____ & Cheek, M. (2009). Warneckea austrooccidentalis, a new species from Cameroon and Nigeria, and a re-evaluation of W. fascicularis var. mangrovensis (Melastomataceae-Olisbeoideae). Kew Bull. 64: 307 – 312.