Taxonomic studies in the Schizymeniaceae (Nemastomatales, Rhodophyta): on the identity of Schizymenia sp in the Azores and the generic placement of Nemastoma confusum

Comparative rbeL. sequence analysis indicates that the species going under the name Schizymenia dubyi in the Azores should be referred to as S. apoda. Sequences of Sehizymenia specimens from China and Namibia were also identified as S. epode, of which the type locality is the Cape Province in South Africa. Sehizymenia dubyi, described from Atlantic France, is clearly a distinct species that we here report for Japan and Sicily in the Mediterranean Sea. Both Schizymenia species, along with an unreported species from Japan, are distinct from S. pacifica described from Washington, in the Pacific Coast of North America. Secondary pit connections were observed in gametophytes of S. epode from the Azores, a previously unknown character for the Nemastomatales. Examination of type material of Nemastema confusum indicates that this species, currently placed in the Nemastomataceae, should be transferred to the genus Mamma in the Schizymeniaceae. A morphological comparison between Mamma confusum (Kraft & John) comb. nov. with descriptions or P. cyclocolpum and P. chrysymenioides suggests that the three species are closely related.