A revision of 45 South African species of Argyrolobium is presented comprising nomenclature, typification, recorded distributions and full descriptions. In an attempt to reduce confusion between subtly different species, diagnostic characters are listed and comprehensive illustrations are provided. The dissertation includes numerous taxonomic and nomenclatural changes. Currently two sections are recognised based on fruit morphology. This is replaced by a system of five new sections based on morphological, micromorphological and phytogeographical evidence. Constraints and advantages of floral dimorphism and monomorphism are discussed with respect to the fecundity and distribution of sections. It is proposed that the occurrence of facultative cleistogamy in two sections has enhanced their success and distribution. Generic and specific phylogeny is interpreted using models generated through cladistic methodology. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1994.