Studies in the genus Riccia (Marchantiales) from southern Africa. 8. R. campbelliana (subgenus Riccia), newly recorded for the region

Abstract

R. campbelliana Howe (1899), a rare species originally known from California and later from Georgia, Arkansas (Jacobs 1951; Wittlake 1954), Kansas and Nebraska (S. Jovet-Ast pers. comm.), as well as from Kazakhstan (Ladyzhenskaja 1967), has now also been found at a few localities in southern Africa. It is characterized by the distinctive yellow-brown or rusty colouration of the dorsal surface along the margins and over the proximal parts; enlarged cells, ‘idioblasts', which differ in shape and contents from the adjacent cells, are generally found in all parts of the thallus.