A revision of Heterolepis Cass. (Asteraceae: Cichorioideae)

•A full literature review, description, character illustrations, and distribution maps are provided for all four species of Heterolepis.•An important character, the possession of milky sap, is documented for the first time in the genus.•Nomenclature of all names associated with Heterolepis is provided.

The small Cape genus Heterolepis (Asteraceae: Cichorioideae) containing four species, is poorly known and its tribal affinities within the subfamily are enigmatic. The genus has not been taxonomically treated since the 1865 publication of Harvey and Sonder's Flora Capensis, and a new species was recently described. Here, we collate information from the more than 200 collected specimens, combined with a detailed morphological investigation of each species, and present a full revision of the genus. A review of previous work, the taxonomic history, intrafamilial phylogenetic affinities, and morphological characteristics of Heterolepis are presented, together with a key to the species and detailed images of floral features. For each species a nomenclatural review, detailed description and observations, illustrations of selected features, distribution map and list of examined specimens is provided, as well as a full list of all relevant literature and a database of existing specimens.