The endemic plant species of Mt Kupe, Cameroon with a new Critically Endangered cloud-forest tree species, Vepris zapfackii (Rutaceae)

Abstract

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, Vepris sp. 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 species V. montisbambutensis Onana and V. bali Cheek, concluding that it is a new undescribed species here named as Vepris 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 zapfackii and V. bali appear unique in African trifoliolate species of the genus in having opposite leaves. Vepris zapfackii differs 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).

A taxonomic synopsis of unifoliolate continental AfricanVepris(Rutaceae) with three new threatened forest tree species from Kenya and Tanzania

“…The genus was last revised for tropical Africa by Verdoorn (1926). Founded on the Flore du Cameroun account of Letouzey (1963), nine new species were recently described from Cameroon (Onana & Chevillotte 2015;Cheek et al 2018a;Onana et al 2019;Cheek & Onana 2021;Cheek et al 2022a), taking the total in Cameroon to 24 species, the highest number for any country globally, followed by Tanzania (16 species). The greatest concentrations of Vepris species in Cameroon are within the Cross-Sanaga Interval (Cheek et al 2001) with 15 species of Vepris of which nine are endemic to the Interval.…”

“…2018a; Onana et al . 2019; Cheek & Onana 2021; Cheek et al . 2022a), taking the total in Cameroon to 24 species, the highest number for any country globally, followed by Tanzania (16 species).…”

Impatiens banensp. nov. &I. etugeisp. nov. (Balsaminaceae), threatened lowland species of the Cross-Sanaga Interval, Cameroon

“…2021; Alvarez-Aguirre et al . 2021; Cheek & Onana 2021; Cheek et al . 2021a; 2021b; in press; Gosline et al .…”

“…New species to science from Cameroon are being published steadily, from herbs of waterfalls, forest shrubs to canopy trees (Achoundong et al 2021;Alvarez-Aguirre et al 2021;Cheek & Onana 2021;2021b;in press;Gosline et al 2022). Many of these species, including those described in this paper, were collected as part of a programme to produce a series of conservation checklists (see below) for areas of intact natural habitat ranging over much of the Cross-Sanaga interval (Cheek et al 2001).…”

Monanthotaxis bali (Annonaceae) a new Critically Endangered (possibly extinct) montane forest treelet from Bali Ngemba, Cameroon

“…About 2000 species of vascular plant have been described as new to science each year for the last fifteen years or more. Cameroon currently has the highest number of new species to science published each year(Cheek et al 2020b), recent examples being published are(Achoundong et al 2021;Aguirre-Alvarez et al 2021;Cheek et al 2021a;2021b;2021c;Cheek & Onana 2021; Couvreur et al in press; Gosline et al 2021). While some exceptions exist(Cheek & Etuge 2009;Cheek et al 2019…”