A New Species of Drypetes (Euphorbiaceae) from Western Cameroon

Cheek, Martin; Radcliffe-Smith, A.; Faruk, Adam C.

doi:10.2307/4113635

Cited by 3 publications

(2 citation statements)

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“…A summary can be found in Cable & Cheek (1998). Apart from Oxygyne triandra, numerous other narrowly endemic and threatened species are recorded from this forest, e.g., Drypetes moliwensis (Cheek, Radcliffe-Smith & Faruk, 2000), Cola cecidifolia Cheek (Cheek, 2002), Salacia nigra Cheek (Gosline, Cheek & Kami, 2014), Psychotria moliwenis Bridson & Cheek, P. bimbiensis Bridson & Cheek (Cheek & Bridson, 2002) and Ancistrocladus grandiflorus Cheek (Cheek, 2000). …”

Section: Taxonomic Treatmentmentioning

confidence: 99%

Taxonomic monograph of Oxygyne (Thismiaceae), rare achlorophyllous mycoheterotrophs with strongly disjunct distribution

Cheek

Tsukaya

Rudall

et al. 2018

PeerJ

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Oxygyne Schltr. (Thismiaceae) is a rare and little-known genus of achlorophyllous mycoheterotrophic perennial herbs with one of the most remarkable distributions of all angiosperm plant genera globally, being disjunct between Japan and West–Central Africa. Each species is known only from a single location, and in most cases from a single specimen. This monographic study names, describes and maps two new species, Oxygyne duncanii Cheek from cloud forest in SW Region Cameroon and O. frankei Cheek from gallery forest in the Central African Republic, representing the first new Oxygyne species described from Africa in 112 years, and raising the number of described Oxygyne species from four to six. Oxygyne duncanii is remarkable for sharing more morphological characters with two of the three Japanese species (O. hyodoi C.Abe & Akasawa, O. shinzatoi (H. Ohashi) Tsukaya) than with the geographically much closer type species of the genus, O. triandra from Mt Cameroon. Based mainly on herbarium specimens and field observations made in Cameroon and Japan during a series of botanical surveys, we provide descriptions, synonymy, mapping and extinction risk assessments for each species of Oxygyne, together with keys to the genera of Thismiaceae and the species of Oxygyne. The subterranean structures of African Oxygyne are described for the first time, and found to be consistent with those of the Japanese species. We review and reject an earlier proposal that the Japanese species should be segregated from the African species as a separate genus, Saionia Hatus. The only character that separates the two disjunct species groups is now flower colour: blue or partly-blue in the Japanese species compared with orange-brown in the African species. Studies of the pollination biology and mycorrhizal partners of Oxygyne are still lacking. Two of the six species, O. triandra Schltr. and O. hyodoi, appear to be extinct, and the remaining four are assessed as Critically Endangered using the IUCN 2012 criteria. To avoid further extinction, an urgent requirement is for conservation management of the surviving species in the wild. Since few achlorophyllous mycoheterotrophs have been successfully cultivated from seed to maturity, ex situ conservation will not be viable for these species and protection in the wild is the only viable option. While natural habitat survives, further botanical surveys could yet reveal additional new species between Central Africa and Japan.

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Section: Taxonomic Treatmentmentioning

confidence: 99%

Taxonomic monograph of Oxygyne (Thismiaceae), rare achlorophyllous mycoheterotrophs with strongly disjunct distribution

Cheek

Tsukaya

Rudall

et al. 2018

PeerJ

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“…It is possible that Memecylon ebo will yet be found at additional locations in Cameroon outside Ebo. However, while surveys have not been exhaustive, many thousands of specimens have been collected in areas to the north, south, west and east of Ebo (Cheek et al 1992; Cheek et al . 1996; Cable & Cheek 1998; Cheek et al .…”

Section: Methodsmentioning

confidence: 99%

The endemic plant species of Ebo Forest, Littoral Region, Cameroon with a new Critically Endangered cloud forest shrub,Memecylon ebo(Melastomataceae-Olisbeoideae)

Stone,

Tchiengué,

Cheek

2023

Preprint

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SummaryWe emphasise the urgent need to conserve the Ebo forest (Littoral Region, Cameroon), which holds 10 strict endemic plant species and 15 near endemics for a total of 25, a very high number far exceeding the threshold for its recent status as an Important Plant Area (IPA). We describe a further strict endemic species from the Ebo Forest,Memecylon ebosp. nov. (Melastomataceae-Olisbeoideae) placed in sect.Afzelianadue to its ellipsoid blue-green fruits. The yellow petals and jade green anther-connectives ofM. eboare unique in the genusMemecylonas a whole, among its >400 species ranging overall from Africa to the western Pacific.Memecylon ebois assessed as Critically Endangered (CR) using the 2012 IUCN standard due to the small range size and the extremely high and ongoing threats of logging at Ebo, and also due to subsequent threats of potential oil palm plantation and mining projects. With the addition ofMemecylon ebo, the tally of Critically Endangered plant species recorded from Ebo forest is now the highest of any IPA in Cameroon, equalling that of, Ngovayang with 24 CR species.

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Notes on the threatened lowland forests of Mt Cameroon and their endemics including Drypetes burnleyae sp. nov., with a key to species of Drypetes sect. Stipulares (Putranjivaceae)

2021

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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.

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A New Species of Drypetes (Euphorbiaceae) from Western Cameroon

Cited by 3 publications

References 1 publication

Taxonomic monograph of Oxygyne (Thismiaceae), rare achlorophyllous mycoheterotrophs with strongly disjunct distribution

Taxonomic monograph of Oxygyne (Thismiaceae), rare achlorophyllous mycoheterotrophs with strongly disjunct distribution

The endemic plant species of Ebo Forest, Littoral Region, Cameroon with a new Critically Endangered cloud forest shrub,Memecylon ebo(Melastomataceae-Olisbeoideae)

Notes on the threatened lowland forests of Mt Cameroon and their endemics including Drypetes burnleyae sp. nov., with a key to species of Drypetes sect. Stipulares (Putranjivaceae)

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