Study on the fern flora in grassland of Gansu Province

In order to fully understand the distribution characteristics and geographical elements of fern flora and reveal their process of natural history in the Gansu Province grassland, the present study investigated the fern in this area and analysis the floristic composition and geographical distribution. The results show that there are 31 species which belong to 19 genera and 14 famlies in Gansu rangeland which accounts for 22.22% of the total family, 8.26% of the total genus, 1.99% of the total species of China ferns resources (63 families 230 genera and 2 600 species) , respectively. The dominant families are Dryopteridceae and Polypodiaceae; dominant genera are Selaginella and Woodsia. The family is mainly tropical distribution type and the genus is mainly tropical and temperate distribution without endemic genus. Vertical distribution is obvious containing old families and genera. The richness of fern in Gansu grassland is not high.