Abstract
A taxonomic revision of the genus Geissospermum Allemão (Apocynaceae) is provided. Identification key, descriptions and illustrations of the species are presented, as well as data on geographical distribution and taxonomic comments. The following species are recognized: G. argenteum, G. reticulatum, G. sericeum, G. urceolatum and G. vellosoi. Geissospermum fuscum and G. laeve are synonymized in G. sericeum and G. vellosoi, respectively. After a careful analysis of the protologues of G. laeve and G. vellosoi, we concluded that the basionym for the type species of the genus is Tabernaemontana laevis, for which a lectotype was elected. Leaf blade indumenta characters were particularly useful for species recognition.