A revision of the genus Melolobium (Genisteae, Fabacaeae)

Melolobium is a hitherto poorly known southern African papilionoid genus of the family Fabaceae. Although 20 species have previously been described, in the present revision, we recognize only 15 species. The genus appears to have close affinities with a number of other African genistoid genera (Adenocarpus, Argyrolobium, Dichilus and Polhillia), but can be distinguished by the often spiny habit, auriculate stipules and presence of glands (stalked and sessile) in most species of the genus. A cladistic analysis of morphological and anatomical characters resulted in a partially resolved cladogram in which virgate, non-spiny species are sister to the divaricately branched spiny group of species. The correct nomenclature, typification of names, descriptions, geographical distributions and a key to all the species of Melolobium are presented.