The first comprehensive treatment of the Pteridophyta of Southern Africa was the first edition (1892) of T. R. Sim's The Ferns of South Africa. Over the past thirty years the senior author has travelled widely in this region in the course of field work on this group. On overseas visits the type specimens of species occurring in this area have been searched for and examined as far as possible. Most of the genera have been studied on a pan-African basis as a necessary background to the present treatment which led also to the publication of the pteridophyte volumes of the Flora Zambesiaca (1970), Conspectus Florae Angolensis (1977), Flora de Moçambique (1979) and taxonomic reviews of a number of fern families in continental Africa.
Although a number of more recent classifications of the ferns have been proposed and a number of genera redefined, the arrangement in this treatment follows that in the above works for the sake of compatibility. Generic and species concepts are mostly construed in the wide sense either for convenience or so as not to obscure phytogeographic relationships. However, a number of these aggregate species and genera require cytotaxonomic study for their elucidation.