The Floristic Characteristics in the Region of Xiqing Mountains

The region of Xiqing Mountains is situated between latitude 33°80′～35°50′N and longitude 100°10′～102°40′E. There are 711 species of seed plants that belong to 56 families and 257 genera in this region. The floristic characteristics in the area are as follows: (1) The Temperate elements has a percentage of 96.88%, it shows the clear nature of the Temperate Zone that is the decisive factor of the floristic characteristics. (2) Most of the cosmopolitan elements and the endemic elements of China are developed from them relational genera that are wildly distributed. Shows the flora is a young and derivative flora. (3) The main vegetation such as alpine meadows, alpine thickets and alpine moor meadows are all alpine type typical. Most of the constructive species of them are character species of typical alpine vegetation. Therefore, in this flora, the alpine vegetation are typical, and the characteristic species are typical, and the feature of alpine and plateau flora is obvious. (4) It is specially glaring the selection of ecological factor and the alpine specialization, and appearance to adapt hydro-coldize, and coldize and droughtize in the flora. It depends on the ecological environment that is formed by the geographical position, the elevation and the climatic characteristics. This flora is one of the representatives flora of the Tanggute flora. However, by the analysis of the endemic species of China, the flora is close relationship with both the floras of Hengduan Mountains and Southern Gansu. Its the richest common species between the three areas, and including 363 species and has a percentage of 66 73% of total endemic species of China in this area. Its such a similarity to support Professor Li Xiwen( 1993) who is about the dividing of “the subregion of Northwest Sichuan-Southwest Gansu-Southeast Qinghai” in Hengduan Mountains undoubtedly and strongly.