Four new species in the endemic genus Rhodocolea Baill. (Bignoniaceae) from Madagascar

A recent review of the Malagasy Bignoniaceae for the Catalogue of the Vascular Plants of Madagascar has enabled us to discover new species in most genera in the family. In this part of a series of publications detailing the necessary taxonomic changes, we provide descriptions of four new species in the endemic Malagasy genus Rhodocolea: R. humbertii Callm. & Phillipson, R. magnifica Callm. & Phillipson, R. parvifoliolata Callm. & Phillipson and R. ranirisonii Callm., Phillipson & L.Gaut. Each of the new species is provided with line drawings, a discussion of its morphological affinities and a conservation threat analysis based on the IUCN Red List Categories and Criteria.