Peltiera (Fabaceae), the coming and going of an “extinct” genus in Madagascar

Peltiera Du Puy & Labat is a Malagasy genus of two described species thought probably to be extinct at the time of its publication in 1997, when it was known only from a total of three pre-1950 collections. However, recent field work in east-central Madagascar has resulted in the discovery of still extant populations, and therefore it is now possible to reconsider the phylogenetic position and status of the genus and its two species. Phylogenetic analyses based on molecular (chloroplast trnK and nuclear ribosomal ITS sequences) and morphological data corroborate the close relationship between Peltiera and Ormocarpopsis R. Vig., a genus of six species, also endemic to Madagascar. Peltiera differs from Ormocarpopsis mainly by having articulated, dehiscent fruits, and the two genera together are, in turn, sister to the widespread but mainly African Ormocarpum P. Beauv. Morphological, distributional and habitat data gathered from the new collections show that only a single species of Peltiera can be recognized, and as this species shares important synapomorphies with all species of Ormocarpopsis, it is transferred to this genus as O. nitida, comb. nov. A distribution map and photographs of O. nitida comb. nov. are presented, and a conservation threat analysis of the species is provided. The name Ormocarpopsis is lectotypified and an amended description of the genus with its new circumscription is given.