Abstract
Croton sect. Barhamia subsect. Medea is a South American group represented by a number of endemic and rare species, most of them subshrubs with small vegetative and floral structures. The Brazilian ‘campos rupestres’, mostly inserted in the savanna areas of Minas Gerais State, are one of the centers of species diversity of the subsection. The species of subsection Medea from Brazilian campos rupestres share a morphological pattern, which is characterized by features of stipules, bracts and sepals such as type of margin (entire or laciniate), the presence or absence of glands, and the type of gland insertion (sessile or stipitate). Based on new material collected and the study of type material, detailed species descriptions, illustrations, taxonomic keys to the species, and data on geographic distributions are provided. Lectotypes are designated for seven species. The rediscovery of Croton staechadis is also recorded.