Dicranum shennongjiaense W.Z.Huang & R.L.Zhu (Dicranaceae, Bryophyta), a new species from Central China supported by morphological and molecular evidence

Introduction: Dicranum Hedw. is one of the most taxonomically challenging genera of mosses, having 93 accepted species worldwide. Although recent integrative taxonomic revisions have clarified the delimitation of most species within this genus, the circumscriptions of some Dicranum species remain unsolved. During our recent survey of Dicranum in China, an intriguing species with an unknown combination of morphological traits was discovered in the Shennongjia National Nature Reserve, Central China. We carried out a study to provide morphological and phylogenetic evidence with which to determine the taxonomic status of this Chinese species. Methods: The phylogenetic evidence was obtained through the combined analysis of five loci (rps4–trnT, trnL–trnF, trnH–psbA, rps19–rpl2 and rpoB) and one nuclear region (nrITS1–5.8S–ITS2). Morphological characteristics were investigated by microscopic examination of specimens. Key results and conclusions: A new moss species, Dicranum shennongjiaense W.Z.Huang & R.L.Zhu, is described and illustrated based on molecular and morphological evidence. This new species is characterised by its falcate leaves, rectangular and elongated laminal cells with strongly protruding upper angles on the dorsal side in the upper leaf portion, irregularly bistratose laminal cells above the midleaf, one layer of guide cells in the costa, and sharp serrations on the dorsal side of the costa in the upper leaf portion. Additionally, D. baicalense Tubanova, previously known only from Russia, is newly reported for China. A key for identification of the Chinese species of Dicranum sect. Dicranum is provided.