A taxonomic account is given ot the genus Plagiochasma Lehm. & Lindenh. and its two subgenera. Micropvlum Bischl. and Plagiochasma. The first subgenus is represented in southern Africa by P. rupestre var. rupestre (J.R. & G. Forst.) Steph. and P. rupestre var. volkii Bischl.: the second by P. appendiculatum Lehm. & Lindenb. (newly recorded for the region). P. heccarianum Steph.. P eximium (Schiffn.) Steph. and P. microcephalum (Steph.) Steph. var. microcephalum. Descriptions and illustrations of these taxa together with distribution maps and a key to the subgenera and species are provided. Keywords: Hepaticae, Marchantiales, Plagiochasma appendiculatum, P. heccarianum, P. eximium, P. microcephalum var. microcephalum, P. rupestre var. rupestre, P. rupestre var. volkii, southern Africa.