Studies On Taxonomy And Flora Of Pottiaceae In China

Detailed investigation and research on the flora of Pottiacea will provide not only basic information to the protection of species diversity but also samples for studying physiology, developmental biology and phylogeny of Pottiaceae. However, there are lots of difficulties in traditional Pottiaceae classification and identification due to intrinsic problems such as polymorphy, taxonomic importance of anatomical characters, obscure areolation, and sterility of many specimens.According to statistics,39genera,179species and varieties of the family are considered to be taxonomically recognizable entitles in China.3genera and22species are new to China. Keys to the genera and species, herbarium numbers of collection and detailed discussion are given.The author conducted a preliminary analysis of the Pottiaceae components. In Chinese moss species composition,6dominant genera (over and including10species) Barbula, Bryoerythrophyllum, Desmatodon, Didymodon, Hydrogonium, Syntrichia, consist of81species, which make up45.25%of the total number. Didymodon is the first major genera, of26species, which occupies14.53%of the total number.The species of Pottiaceae could be grouped into10geography distribution types as Cosmopolitan (7.82%), Tropical Asian—Tropical American elements (2.23%), Tropical Asian—African elements (2.23%), Tropical Asian elements (5.59%), North Temperate elements (36.87%), Asian and North American elements (7.26%), Old World Temperate elements (2.23%), East Asian elements (16.76%), Temperate Asian elements (1.68%) and Endemic to China (17.88%).The Pottiaceae in China shows distinct characteristics of those in Temperate Zone, North Temperate elements play an leading role, the Endemic to China and the East Asia elements are important parts of all elements, and makes it full of China and the East Asia features. The statistics of geographical distribution indicate that Yun-Gui region had the highest species diversity (132species,73.74%), the Mengxin region (122species,68.16%) is second to it, and the lowest diversity appears in Northeast region (59species,32.96%). The similarity coefficient of species shows that the flora of China is closer to those of Japan and North America, while farthest to Europe.