Chamaebotrys erectus sp nov (Rhodymeniales, Rhodophyta) from the Socotra Archipelago, Yemen

A third species of Chamaebotrys, C erectus, is described from an upwelling region off Socotra Island, Yemen. The new species clearly displays one of the defining features of the genus, viz. terminal tetrasporangia in nemathecial sori. ne nemathecia become diffuse when mature and produce secondary tetrasporangia. Tetraspores can apparently germinate in situ, resulting in compound thalli with tetrasporic and cystocarpic parts. Carpogonial branches are four-celled and cystocarps are protuberant, both of which features illustrate the affinities of Chamaebotrys with the closely related Coelarthrurn.