The genus Exochaenium (22 species) is endemic to sub-Saharan Africa, with species occurring in most tropical and sub-tropical regions of the continent, particularly on the Katanga plateau (Angola, Democratic Republic of Congo and Zambia), with many extending to the Sudano-Zambesian and Guineo-Congolian regions. The genus is monophyletic and is used to study the variation and evolution of herkogamy.