A new species of Riccia, R. rosea Volk and Perold of the group 'Squamatae', section Riccia. subgenus Riccia. is described. It is endemic to southern Africa and is characterized by large ventral scales with hyaline margins and reddish pink to deep rose-pink bases, and bv the light green dorsal colour of the thallus. fading to white along the margins and older parts. Fertile male plants have prominent hyaline ostioles. The spores are globular or subglobular and apolar. with 9-11 well defined areolae across the diameter. Keywords: Marchantiales. Riccia rosea, species nova, southern Africa. 'Squamatae', taxonomy.