Lindenberg (1836) regarded and published Riccia stricta as a variety of R. fluitans L. Subsequently, Nees (1838) and Gottsche et al. (1846) also treated it as a variety. Trevisan (1877) raised its rank and published the epithet, Ricciella stricta Trevis. Ricciella is, however, regarded as a subgenus; Ricciella stricta is, therefore, transferred to Riccia stricta (Lindenb.) Perold. It is described in detail and illustrated. R. purpurascens Lehm. & Lindenb., a related endemic species, is also more fully described than before and illustrated. R. fluitans L. apparently does not occur naturally in southern Africa. As far as is known, a single local specimen of it was introduced. Keywords: Marchantiales, Riccia fluitans, R. purpurascens, R. stricta, southern Africa, subgenus Ricciella, taxonomy.