Révision du genre Bathiorhamnus Capuron (Rhamnaceae) endémique de Madagascar

The Malagasy endemic genus Bathiorhamnus Capuron (Rhamnaceae) is revised taxonomically. Seven species are recognised, based on our study of morphological characters. In addition to the two previously-described species: B. cryptophorus Capuron and B. louvelii (H.Perrier) Capuron, the delimitation of the three varieties recognised in the latter is amended and they are raised to the species level: B. dentatus (Capuron) Callm., Phillipson & Buerki, B. macrocarpus (Capuron) Callm., Phillipson & Buerki, B. reticulatus (Capuron) Callm., Phillipson & Buerki. Two new species are described: B. capuronii Callm., Phillipson & Buerki, from the dry forests in the west and north of Madagascar and B. vohemarensis Callm., Phillipson & Buerki from littoral forest near Vohémar in the northeast. A key to the species of Bathiorhamnus is presented as well as preliminary assessments of the conservation status for each species.