Two new species of Raphia (Palmae/Arecaceae) from Cameroon and Gabon

PhytoKeys. 2018 Nov 6:(111):17-30. doi: 10.3897/phytokeys.111.27175. eCollection 2018.

Abstract

Raphia (Arecaceae, Calamoideae) is the most diverse genus of African palms with around 20 species. Two new species from Cameroon and Gabon, Raphiagabonica Mogue, Sonké & Couvreur, sp. nov. and Raphiazamiana Mogue, Sonké & Couvreur, sp. nov. are described and illustrated. Their affinities are discussed and the conservation status of each species is assessed. For both species, distribution maps are provided. Raphiagabonica is restricted to two small populations from central Gabon, where it occurs on hillsides on tierra firme soil, and close to small streams. Its preliminary IUCN status is Endangered, being amongst the five most threatened palm species in Africa. Raphiagabonica potentially belongs to the moniliform section. Raphiazamiana is largely distributed from south Cameroon to south Gabon and is very common. It is also a multi-used palm, from which wine, grubs and construction material are extracted and sold. It generally occurs in large stands in a wide range of ecosystems such as swamps, coastal forests on partially inundated sandy soils and inundated savannahs. Its large stature, hard to access habitat (swamps) and abundant presence might have discouraged botanists to collect it until now. Raphiazamiana belongs to the taxonomically complex raphiate section.

Keywords: Arecaceae; Calamoideae; Raphia; Cameroon; Gabon; IUCN conservation status; new common species.