A new species of Thilachium (Capparaceae) from the Analanjirofo Region, Madagascar

Madagascar is a centre of speciation for the genus Thilachium Lour., which includes several species of small trees and shrubs occurring in a wide range of habitats. A new species of Thilachium, T. latifolium Fici, from the Analanjirofo Region of northeastern Madagascar is here described and illustrated. It is characterised by 1-foliolate leaves, leaf blades widely ovate or elliptic with shortly acuminate or acute apices, flowers in terminal, dense subumbels or corymbs, short pedicels and ellipsoid, ribbed fruit. The new species is related to T. madagascariense Fici, a species recently described from eastern Madagascar, differing in the wider, coriaceous leaves with shorter, mucronulate tip, flowers in terminal, 7–16-flowered subumbels or corymbs, shorter pedicels and longer anthers. The distribution, autecology and affinities of the new species are discussed, its conservation status is assessed, and an updated key is provided for the species of the genus Thilachium known from Madagascar.