CLATHROMORPHUM TUBIFORME SP-NOV (RHODOPHYTA, CORALLINACEAE) IN SOUTH-AFRICA WITH COMMENTS ON GENERIC CHARACTERS

A nongeniculate, crustose coralline alga (Rhodophyta, Corallinaceae) f rom South Africa, is found growing epiphytically on fronds of species of the geniculate genus Amphiroa. Analysis of the vegetative and repro ductive morphology and anatomy of the alga shows that it belongs to th e subfamily Melobesioideae and genus Clathromorphum. It is the only kn own representative of the genus in South Africa. It has tetrasporangia l conceptacles that are significantly smaller than those of any other described species of the genus and it is described as the new species Clathromorphum tubiforme. The diagnostic features of Clathromorphum an d other genera of the Melobesioideae are discussed and it is considere d that, among melobesioid genera, Clathropmorphum is probably most clo sely related to Melobesia.