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

SummaryTwo tree species are described as new to science: Rinorea spongiocarpa Achound. sp. nov (placed in Rinorea [unranked] Brachypetalae) and Rinorea dimakoensis Achound. sp. nov.( placed in Rinorea [unranked] Ilicifolieae). Both species are endemic to Cameroon, occurring south of the Sanaga river, the first from South and East Regions, occurring in evergreen forest from Ebolowa to Dja, while the second occurs 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 illustrated, and their affinities and conservation status according to the 2012 IUCN categories and criteria are discussed. Both species are threatened with extinction due to habitat destruction, the first is assessed as Vulnerable, the second Endangered.