关键词: 塔吉克斯坦, 种子植物, 植物区系, 分布区类型

Abstract: Tajikistan is an inland country located in Central Asia with special flora position, unique and abundant species. Study on characteristics of this flora has important significance for further comprehensive understanding the status，origin and evolution of plant resources in Central Asia. Through the literature collecting，field investigation，specimen examination， the seed plant flora characteristics in Tajikistan was systematically analyzed. The results showed as follows：（1）The wild seed plants in Tajikistan have the characteristics of high richness and uniqueness，there are totally 4 115 species of the wild seed plants belonging to 864 genera in 110 families，including 770 endemic species.（2）There are 13 large families with more than 100 species，which only accounts for 11.82% of total number of families，but accounts for more than 70% of the total number of seed plants. These families play dominant role in the flora of Tajikistan. On the other hand，emergencey of nearly 50% single-species and oligo-specific families indicates that environment condition in Tajikistan is quite vulnerable also. For the composition of genera，single-species and oligo-specific genera is also abundant here，which is one of the main reasons of constituting the diversified flora in Tajikistan.（3）The seed plant flora has wide connection in geographical relationship on both family level and genus level. The flora is composed of temperate elements and tropical elements. Comparing with tropical elements，temperate elements take up absolute predominance in Tajikistan. There are 33 temperate families，occupying 55.93% of the total number of families (excluding the Cosmopolitan families)，and 712 genera， occupying 91.05% of the total number of genera (excluding the Cosmopolitan genera)，which suggests that this flora is characterized with obvious temperate features. The tropical components occupy a relatively high proportion on the family level， indicating the connection with the tropical flora. And it also suggests that the tropical components bring an extensive but weak influence on the flora of Tajikistan. The modern complicated mountain topography and low-lying river valley may create or provide the natural refuge for the thermophile plants. As a result，this flora is temperate in nature with wide connection with tropical components. Species is abundant and mixed with cold-resistant and thermophile plants.（4）There is no endemic family in this flora and only 6 endemic genes which accounted for 0.77% of the total genera （excluding the Cosmopolitan genus），but the endemic phenomenon is obvious on species level，confirming that this flora is young with the characteristics of  distinct  and continuous evolution.

Key words: Tajikistan, seed plants, flora, areal types