Systematics of Hypnea (Cystocloniaceae, Rhodophyta) from coastal North Carolina, with a first report of Calliblepharis saidana from the United States Atlantic Coast

Abstract

Abstract Complete and/or partial DNA sequences for the plastid-encoded rbcL gene and the 5′ end of the mitochondrial cytochrome oxidase I (COI-5P) gene were used to re-examine the systematics of Hypnea species (Cystocloniaceae, Rhodophyta) from North Carolina, USA. These data, combined with light microscopic observations, indicate that two species (Hypnea cryptica and H. musciformis sensu stricto) are present in nearshore waters of coastal North Carolina. Molecular and morphological analyses with topotype material of Hypnea volubilis from North Carolina offshore waters revealed that it and Calliblepharis saidana are conspecific. Hypnea volubilis is proposed as a heterotypic synonym of C. saidana. This is the first report of Calliblepharis from the United States Atlantic coast and only the second report from the western hemisphere.