Intercontinental dispersal often creates diverse, species rich clades, but some lineages persist with only a few surviving taxa. Cnidone, previously known under the illegitimate name Kissenia, is the only African genus of the predominantly American family Loasaceae. Despite being recognised for nearly 200 years and comprising only two extant species, its nomenclature remains unusually complicated. The present study addresses nomenclatural ambiguities and provides an updated taxonomy and species descriptions. It draws on extensive material from more than 200 herbarium specimens housed in 18 herbaria, as well as observations of cultivated plants, and offers detailed morphological and distributional data. Because efforts to conserve the widely used but illegitimate name Kissenia were unsuccessful, publication of the correct names is required for future use. We designate lectotypes where necessary and propose the names Cnidone capensis for the southern African species and C. arabica for the northeast African-southern Arabian species. Their morphology overlaps considerably, and several botanists have treated them as synonyms, contributing to the nomenclatural confusion. We find that, despite considerable phenotypic and ontogenetic plasticity, Cnidone capensis typically has narrower, more deeply lobed leaves and lamelliform nectar scale ligulas, whereas C. arabica generally shows broader leaves and filiform ligulas.