Neosiphonia yongpilii sp. nov. (Rhodomelaceae, Rhodophyta), known asNeosiphonia simplexfrom Korea, with an emphasis on cystocarp development

:A critical re-examination of recent collections and herbarium specimens from Korea previously referred to Neosiphonia simplex (Hollenberg) Y.Lee showed them to be incorrectly identified. The phylogenetic analyses of rbcL sequences demonstrated that ‘N. simplex’ from Korea formed a clade distinct from other species in Polysiphonia sensu lato, and was clearly separate from N. simplex from California, with high sequence divergence. We propose N. simplex sensu Y.Lee from Korea as the new species, Neosiphonia yongpilii sp. nov. This novel species was characterized by severely twisted erect axes, with two to three pinkish sterile cells at apices of spermatangial branches. We also noted that lateral and basal sterile cell groups remain until maturation of the gonimoblast, and that the origin of inner and outer cortical filaments of the pericarp are central cells and pericentral cells respectively.