HARALDIOPHYLLUM EROSUM COMB-NOV (DELESSERIACEAE, RHODOPHYTA) FROM SOUTHERN AND WESTERN-AUSTRALIA

Nitophyllum erosum Harvey (Delesseriaceae, Rhodophyta) is a branched, monostromatic red alga that is readily recognised by its distinctive f ringe of branched, multicellular processes. It has been considered to be a member of the genus Myriogramme Kylin, since it was thought to ha ve carposporangia borne in short chains, a feature partially diagnosti c for that genus. Recent collections of female and cystocarpic materia l have allowed us to ascertain the structure of the procarp, a feature important in generic placement. The procarp includes two periaxial ce lls, of which one acts as a cover cell while the other functions as th e supporting cell, ultimately bearing two sterile cell groups and a fo ur-celled carpogonial branch. In addition, the carposporophyte include s a distinctive fusion cell that incorporates gametophytic cells from the floor of the cystocarpic cavity, and the carposporangia are single and terminal on gonimoblast filaments. This combination of characters is diagnostic of the genus Haraldiophyllum, a genus to which we trans fer this species as Haraldiophyllum erosum (Harvey) Millar & Huisman, comb. nov.