The epidermis of the leaves and fruit of every species of the genus Combretum is covered in scale-like glandular trichomes (subspecies Combretum) or stalked glands (subspecies Cacoucia). In the subspecies Combretum, it has been discovered that both the anatomy of the trichomes and the mixture of the mainly triterpenoid acids and saponins secreted by the trichomes onto the surface of leaves and fruit are species specific. These secretions provide a chemical fingerprint for each species. Thus trichome anatomy and trichome secretions provide an important combination of taxonomically useful characters and these have been used to resolve taxonomic problems in this genus. Chemical fingerprints plus the anatomy of the trichomes for all Southern African species are given and the compounds isolated from these species are reviewed. Based on these findings, the chemical relationships between the Southern African Combretum and those from other continents are discussed. Certain of the saponins isolated are pharmacologically activity, which suggests that these compounds play a beneficial role in the physiology of the leaf surface.