A molecular and morphological investigation of Batrachospermum arcuatum (Batrachospermales, Rhodophyta) in China

► Batrachospermum arcuatum specimens were analysed from seven stream segments in North China. ► Cluster analysis showed that the monoecious specimens were not separated from the dioecious specimens, based on morphology, but rather the specimens were grouped by geographical closeness and habitat similar. ► The rbcL and the cox2-3 spacer data from our research provided more evidence that breeding system (monoecy vs. dioecy) is not a good morphological character to distinguish species.