Cryptogamie, Algologie
26 (1) - Pages 77-89Gracilaria articulata Chang et Xia, previously known from southern China and Vietnam, is reported for the first time from the Okinawa Island, southern Japan.The species is characterized by the following set of morphological features: 1) terete thalli, 2) the presence of articulated segments with attenuated bases and obtuse apices, 3) the presence of traversing filaments in the cystocarp, and 4) shallow, cup-shaped spermatangial conceptacles. Molecular phylogenetic analyses, using the intergenetic spacer regions between the mitochondria encoded cox2 and cox3 genes (cox2-3 spacer), and the plastid encoded rbcL and rbcS genes (RuBisco spacer) supported the conspecificity of the Chinese alga and our Japanese entity, but clearly distinguished G. articulata from morphologically similar species such as G. blodgettii Harvey and G. salicornia (C. Agardh) Dawson.