Studies in the liverwort genus Riccia (Marchantiales) from the south-west Cape

摘要

A new species of Riccia, R. parvo-areolata Volk & Perold, as well as sporophytes and spores of R. villosa Steph. ex Brunnthaler, are described. Earlier descriptions of R. villosa were based on sterile plants. The unique structure of the dorsal epithelium consisting of loose cell pillars in these two species (and also present in allied species grouped together in the section Pilifer) is described and illustrated.