Pterocladiella xiae sp. nov. (Gelidiales, Rhodophyta), a new species from southern China

Turf-forming Gelidiales frequently occur in tropical coral reef regions. It is challenging to identify species correctly due to their small size and simple morphology. In the present study, we combined morphological and molecular phylogenetics methods to study turf-forming species of the genus Pterocladiella from tropical coral reef areas in southern China. Both COI-5P and rbcL gene analyses revealed a novel species described here, Pterocladiella xiae sp. nov. The species was less than 1 cm in height, with a distinctive slender thallus, compressed percurrent axis with up to two orders of ribbon-like branches, and short warty-like branchlets which usually occurred irregularly on the upper thallus. Pterocladiella bartlettii was also recorded in China for the first time. Additional descriptions of reproductive structure in P. musciformis and P. beachiae were also documented. This study enriches our understanding of the biodiversity of Pterocladiella in China and reveals the potential diversity of small turf-forming species in tropical coral reefs.