Three new species of Uvariodendron (Annonaceae) from coastal East Africa in Kenya and Tanzania.

Léo-Paul M.J Dagallier,W.R Quentin Luke,Thomas L.P Couvreur,Frank M Mbago

doi:10.3897/phytokeys.174.61630

Abstract

East Africa is a hotspot of biodiversity with many endemic plant species. We describe three new species of the genus Uvariodendron (Annonaceae) from the coastal forests of Kenya and Tanzania. Uvariodendron mbagoi Dagallier & Couvreur, sp. nov. is endemic to Tanzania and unique within the genus by its strong bergamot scent and its tomentose fruits having regular tufts of higher hair density. Uvariodendron dzomboense Dagallier, W.R.Q. Luke & Couvreur, sp. nov. is endemic to Dzombo Hill in Kenya and is rendered distinct by its small leaves and very densely pubescent carpels. Uvariodendron schmidtii W.R.Q. Luke, Dagallier & Couvreur, sp. nov. is endemic to Shimba Hills in Kenya and differs by its small flowers and fused sepals forming a ring. Following IUCN criteria we assessed U. mbagoi and U. dzomboense as endangered (EN) while U. schmidtii is assessed as Vulnerable (VU). We also propose a new combination: Polyceratocarpus oligocarpus (Verdc.) Dagallier, comb. nov. The description of these three new species underlines the richness in endemics in East Africa and that new discoveries might arise from further botanical exploration of this region.

Highlights

East Africa is one of the richest regions in terms of biodiversity across the continent (Myers et al 2000; Linder 2001)
East Africa harbors an incredible number of endemic species, in the Eastern Arc Mountains and in coastal forests (Burgess et al 1998, 2007; Küper et al 2004)
The three new species are morphologically close to Uvariodendron kirkii Verdc., one of the other Uvariodendron species occurring in East Africa

Summary

Introduction

East Africa is one of the richest regions in terms of biodiversity across the continent (Myers et al 2000; Linder 2001). This region has been described as acting both as a “cradle” (i.e. promoting lineage divergence) and as a “museum” of diversity (i.e. maintaining old lineages), due to its topographical heterogeneity (Dagallier et al 2020). In East Africa, several new species have been described for the region following the publication of the Flora of Tropical East Africa (Vollesen 1980; Verdcourt and Mwasumbi 1988; Johnson et al 1999; Deroin and W.R.Q. Luke 2005; Couvreur et al 2006; Couvreur and W.R.Q. Luke 2010; Marshall et al 2016; Johnson et al 2017; Gosline et al 2019)

Methods

Results

Conclusion