Batrachospermum arcuatum Kylin (Batrachospermales, Rhodophyta), a Freshwater Red Alga Newly Recorded in Taiwan

A freshwater red alga, Batrachospermum arcuatum Kylin, is recorded for the first time to the freshwater algal flora of Taiwan. It was found attaching on submerged stones in a clean river in Yuanshan Village, Yilan County. In addition to describe the morphological and reproductive structures of B. arcuatum in detail, we also used rbcL sequences to confirm its phylognetic relationship to other species of Batrachospermum