Two New Species of Ardisia (Primulaceae) from Southeastern Madagascar
Abstract
Ardisia sharoniae Manjato, Ravololoman.& Razakamal. and A. vohimenensis Manjato, Ravololoman. & Razakamal. (Primulaceae) are described as new species from southeastern Madagascar, the former from the Ankarabolava and Agnakatrika forests (Atsimo-Atsinanana Region) and the latter from the Vohimena range (Anosy Region). They differ from the four currently recognized Malagasy species of Ardisia Sw. by their leaves with serrate margins and their striking angulate twigs. The two new species differ from one another in several characters of their leaves, inflorescences, and fruits. An illustration and a distribution map are provided for each species. Preliminary assessments of the risk of extinction following the IUCN Red List categories and criteria indicate that both are Endangered. An identification key to the seven species of Ardisia occurring in Madagascar is presented.
