Rinorea spongiocarpa and Rinorea dimakoensis (Violaceae), new threatened species of forest trees from East and South Regions of Cameroon and Gabon

Abstract

SummaryTwo tree species are described as new to science: Rinorea spongiocarpa Achound. sp. nov. (placed in Rinorea [unranked] Brachypetalae) and R. dimakoensis Achound. sp. nov. (placed in Rinorea [unranked] Ilicifolieae). Both species occur in Cameroon, south of the Sanaga river, the first from South and East Regions, occurring in evergreen forest from Ngovayang and Lolodorf across the southern plateau to the Dja forest. The second extends also to Gabon, occurring in Cameroon in the northern part of East Region in semi-deciduous forest towards the interface with woodland habitats in the Dimako-Bertoua area. The two species are mapped and illustrated, and their affinities and conservation status according to the 2012 IUCN categories and criteria are discussed. Both R. spongiocarpa and R. dimakoensis are threatened with extinction due to habitat destruction, both are assessed as Vulnerable.