Yamadaella, a new genus in the Nemaliales (Rhodophyta)

Yamadaella (Nemaliaceae, Rhodophyta) is recognized as a new genus, distinct from Nemalion because of its calcification and differing spermatangia, separate from Liagora (Helminthocladiaceae) because of its non-lateral carpogonial branch and axial filaments nearly uniform in diameter, and further differing from all known genera of red algae because divisions of the fertilized carpogonium produce uniseriate filaments resembling vegetative filaments and terminating in tetrasporangia. The general appearance of the gonimoblast suggests that it is a tetrasporophyte similar in some ways to those of certain species of Gymnogongrus (Gigartinales). The type, and only species is Liagora cenomyce Decaisne which includes Liagora rugosa Zanardini, L. holstii Zeh, and L. intricata Butters. It is widely distributed in the tropical and subtropical Pacific and Indian Oceans and in the Red Sea.