Studies in the liverwort family Metzgeriaceae (Metzgeriales) from southern Africa. 1. Metzgeria nudifrons Stephani and a key to the species

This is the first of several projected articles on the taxonomy of southern African Metzgeriaceae H. Klinggr. A brief history of the genus Metzgeria Raddi in southern Africa, the only local representative, is presented. Family and genus descriptions, as well as a key to the species, are provided. Of the seven species currently recognized in southern Africa, M. nudifrons is the only species with gemmae on the dorsal surface of the thallus. It is also characterized by the distinctly broad costa, hairy male branchlets as well as single and straight hairs on the ventral face and margins of the thallus. Metzgeria nudifrons is described, illustrated and its geographical distribution mapped.