Dicranum hengduanensis (Dicranaceae, Bryophyta), a new species with fragile leaves from the Hengduan Mountains in China

Abstract. Dicranum is one of the most diverse and widespread genera within the Dicranaceae. Species diversity and distribution in this genus, however, remain not well known. During our recent expeditions to the Hengduan Mountains in China, we found an interesting moss referrable to Dicranum species that is characterized by the stiff and fragile leaves, bistratose alar cells, and by the costal cross-section in the lower portion without stereid bands with one layer of cells above and below guide cells. Morphological and molecular-phylogenetic analyses based on five chloroplast markers (rpoB, rps4-trnT, rps19-rpl2, trnH-psbA, and trnL-trnF) and one nuclear marker (ITS region) suggest that this unknown moss represents a new species here described as D. hengduanensis. The plastome of this new species presented in this study is the first complete plastome of Dicranum.