A comprehensive revision of the genus Justicia L and, the closely  related genera Siphonoglossa Oersted and Aulojusticia Lindau in  southern Africa was undertaken as part of the Flora of Southern  Africa project. Taxonomic characters re-examined include traditional morphological features and novel characters such as SEM studies of pollen~ seed and indumentum morphology, as well as chromatographic work on floral, pigments. Traditional morphological features examined included habit, the size and shape of leaves, the corolla, anthers and capsules. Inflorescence features were thoroughly re-examined. Pollen morphology was found to be diverse with three types of grain present in the genus. The number of colpi was either two or three and there were major differences in the appearance of the sexine. Pollen and inflorescence type were found to correlate. On the basis of this a natural infrageneric classification was proposed.