Studies in the genus Riccia (Marchantiales) from southern Africa. 17. Three new species in section Pilifer: R. elongata, R. ampullacea and R. trachyglossum
Species in section Pilifer Volk (1983) are often very difficult to identify (Perold 1990b). Most of them require close examination of the dorsal cell pillars in reasonably fresh collections, as these cells can seldom be reconstituted in long dried material.The three species, R elongata. R ampullacea and R trachyglossum, here described as new, have been maintained in cultures for lengthy periods, during which their dorsal cells were studied. The spore ornamentation was also quite useful in separating these species. R elongata is known from eastern Transvaal, R. ampullacea from the Witteberg Mountains of the eastern Cape Province and the Drakensberg Mountains of Lesotho and Natal, and R. trachyglossum is so far known only from (he highlands of Lesotho.