Four new threatened species of Rinorea (Violaceae), treelets from the forests of Cameroon

Abstract

Four species of Rinorea are described as new to science; all four species are endemic to evergreen rain forest in Cameroon. Rinorea villiersii Achound., and Rinorea amietii Achound. are placed in Sect. Crassiflorae Wahlert, while Rinorea dewildei Achound. and Rinorea faurei Achound. fall in Rinorea section Dentatae (Engl.) Wahlert. The first species appears to be endemic to the Sole Forest Reserve northeast of Yabassi in Littoral Region. The second and the third species are found mainly in Littoral and South Regions, Rinorea amietii extending to South West Region and Rinorea dewildei extending to Central Region. The fourth species, Rinorea faurei is an endemic of the Santchou Forest Reserve at the foot of Dschang Plateau in West Region. The affinities of the four species are discussed, they are illustrated and mapped, and their conservation status is assessed. All four species are threatened with extinction according to the 2012 IUCN categories and criteria.