Gelidiophycus(Rhodophyta: Gelidiales): A new genus of marine algae from East Asia

A new genus of gelidioid red algae,Gelidiophycus, is described. Separated fromGelidiumon the basis of a molecular phylogeny and morphological characters, it contains two species,Gelidiophycus freshwaterisp. nov. andG. divaricatuscomb. nov., distributed in East Asia. OurrbcLandcox1phylogenies revealed close relationships ofGelidiophycuswith theCapreoliagroup in Australasia and unidentified taxa in Chile.Gelidiophycusis characterized by repent thalli and lateral branches arising at almost right angles. The occurrence of tetrasporophytes, male and female gametophytes, and carposporophytes in the field indicate that both species have the triphasic type life history, different fromCapreolia. Gelidiophycus freshwaterioccurs in Korea, China, and Japan, andG. divaricatusis found in Hong Kong. We discussGelidiophycusand its two species and provide keys, descriptions, and illustrations.