Morphology and molecular phylogeny of Virescentia guangxiensis (Batrachospermaceae, Rhodophyta)

Two collections of freshwater red algae from Zhejiang and Shanxi Province in China are described morphologically and their phylogenetic relationships investigated through molecular sequencing of the rbcL and COI genes. The molecular sequences show a close relationship to Virescentia guangxiensis, a species previously reported from Guangxi and Henan Province, China, particularly through robust support values for rbcL (97/0.95, 70/0.86 ML and BI, respectively) and COI (100/1.00). Morphologically, one sample is a multiseriate gametophyte stage, the other a uniseriate ‘Chantransia’ stage. The gametophyte morphology is consistent with that reported for Virescentia guangxiensis, including key features such as spirally twisted carpogonial branches, spherical spermatangia and carpogonium with clavate trichogynes. Both samples are therefore identified as Virescentia guangxiensis, extending the morphological, genetic and geographical range of this species.