STUDIES IN THE GENUS RICCIA (MARCHANTIALES) FROM SOUTHERN AFRICA .22. R-RUBRICOLLIS, NOW VALIDATED, TYPIFIED AND DESCRIBED

Riccia rubricollis is a very rare endemic species, only known from a few collections by Duthie at Knysna. Unfortunately she and Garside did not publish anything on it, and Arnell's (1963) description has neither a Latin diagnosis nor was a type specimen cited. These omissions have now been rectified here, following the recent rediscovery of Duthie's collections at BOL. The species is characterised by conspicuous, mostly dark purple antheridial necks in the male plant and the spores have large, deepset areolae on the distal face. Although the species has some features typical of section Ricciella of subgenus Ricciella, it is not placed in this section because the sporangia do not bulge ventrally.