Studies in the genus <i>Riccia</i> (Marchantiales) from southern Africa. 18. New species in section <i>Pilifer</i> from the NW Cape: <i>R. furfuracea</i>, <i>R. vitrea</i> and <i>R. namaquensis</i>

Abstract

Another three new species of Riccia in section Pilifer Volk are described from Namaqualand, namely R. furfuracea, R vitrea and R. namaquensis. There are certainly more undescribed species present in that region, but species from there are often very difficult to distinguish: almost all have hyaline scales, the free-standing dorsal cell pillars need to be examined in living plants and the spore ornamentation is quite variable.