Re-Evaluation Of The Taxonomic Status Of Calyptothecium Hamatum (Mull.Hal.) M. Fleisch (Pterobryaceae, Bryophyta)

Calyptothecium hamatum (Mull.Hal.) M.Fleisch. was described by Muller (1869) as Pilotrichum hamatum, and it was transferred to Calyptothecium by Fleischer in 1905. Its taxonomic status has been controversial. Fleischer (1907) reduced it to synonymy with C. wightii (Mitt.) M.Fleisch. while Noguchi (1965) considered it to be separable from C. wightii by its imbricate leaves and shorter costae, which was followed by Crosby et al. (2000) and Gangulee (1976). It is necessary to check the type specimen to clarify its taxonomic status. Correspondence to: Yu Jia, State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, China. Email: yjia@ibcas.ac.cn