Scapania paraphyllia, a new synonym of Scapania koponenii (Marchantiophyta, Scapaniaceae) with special reference to paraphyllia, pseudoparaphyllia, and paraphyses

Scapania paraphyllia T.Cao, C.Gao, J.Sun & B.R.Zuo and S. koponenii Potemkin are both endemic to China. They share considerable morphological similarities except that the former species has pseudoparaphyllia. In order to elucidate the taxonomic status of the two species, we investigated morphological characters possessed by their type specimens and additional collections, and reconstructed a species phylogeny for S. koponenii, S. paraphyllia, and closely related species. The phylogenetic trees were constructed using maximum parsimony, maximum likelihood and Bayesian inference analyses based on the nuclear marker nrITS and the plastid markers trnL-F region and atpB-rbcL spacer. Both morphological and molecular evidence contradicted the hypothesis that S. paraphyllia and S. koponenii are separate species. The pseudoparaphyllia reported for S. paraphyllia are confirmed as paraphyses. The paraphyllia, paraphyses, and pseudoparaphyllia in Scapania are discussed.