Abstract:

This paper deals with the floristic phytogeography of Pteridophytes of Dulongjiang, which is situated in the north-west of Yunnan, the west of Hengduan Mountains and the south-east margin of Qingzhang Plateau. 41 families, 102 genera and 275 species (including 5 varieties and forms) of pteridophytes have been recorded from this region up to now. The Polypodiaceae is the largest family among this pteridoflora. The geographical distribution of genera and species have been divided into 16 distribution-types and 13 distribution-types in this paper separately (see table 3 and table 4) . In addition, the similarity coefficients between this pteridoflora and those of other 15 regions are included in the present paper in table 5. Ac-cording to the results of the comparison with the species number per unit area, the analysis of geographical elements of the genera and species and the study on the similarity coefficients etc.

Key words: Pteridophytes, Floristic phytogeography, Dulongjiang region