Berlinia, a genus of tropical African trees in the subfamily Caesalpinioideae (Leguminosae), comprises 21 species, five of which were discovered during this study and previously published. A phylogeny of Berlinia based on nucleotide sequence data from the nuclear ribosomal ITS region of 14 species is presented, which places the species in two clades. The two clades appear to be ecologically differentiated: one is exclusively composed of hygrophilous species of evergreen forest, and the other contains species that in all but one case occur in habitats of lower annual rainfall. The genus is almost exclusively West and West-central African, with a center of diversity in coastal Gabon. A single species, B. orientalis, is confined to coastal East Africa. Typically, species of Berlinia are trees of lowland forest, including swamp and gallery forest formations.
Red data assessments for all species indicate that eight are Vulnerable, one is Endangered, and two are Critically Endangered. A dichotomous key and a table of key characters are presented. Each species account includes nomenclature, full description, and distribution map; many species are illustrated.