Studies in the genus Riccia (Marchantiales) from southern Africa. 20.,R. albovestita and its synonyms, R. duthieae and R. sarcosa

Abstract

As has been repeatedly emphasized elsewhere, species in section Pilifer Volk are often very difficult to distinguish (Perold 1990b, 1990c). This is nowhere better illustrated than in the case of R duthieae Volk & Perold and  R. sarcosa Volk &Perold. both initially described as new species, which are now regarded by me as synonyms of R. albovestita Volk. Comparisons are drawn between the thallus dimensions, dorsal cell pillars, spore ornamention and other characters, in support of the above conclusion. An updated distribution map and a list of the specimens examined are added, because several new collections have been made since the original publications.