Abstract: The species delimitation of Lemmaphyllum, including the former segregated Lepidogrammitis in China, was considered as unresolved. Previous treatments accepted between one and 20 species. In the present study, multivariate analysis and maximum parsimony analyses were carried out on data from herbarium specimens of this genus by evaluating 24 quantitative characters and 13 qualitative characters. In total, 558 specimens representing 11 previously accepted species and one variety in China were studied. As a result, three species and two varieties were recognized, Lemmaphyllum pyriforme, L. rostratum, L. carnosum, L. carnosum var. microphyllum, and L. carnosum var. drymoglossoides. Two new combinations and seven new synonyms were introduced. An identification key and distribution maps were provided. This study also elucidated the diagnostic value of two previously ignored characters, scales at the base of stipe and laminae hydathodes.

Key words: hydathodes, Lepidogrammitis, morphological characters, scales, species delimitation, taxonomy.