An investigation of the flora of the Chadegan region in Isfahan province

In this study, the flora of the Chadegan region, in 115 Km of the west of Isfahan investigated. This region is a mountainous area with some small plains and short hills that cover a surface of ca. 10000 hectares. The annual precipitation in the region is about 324.3 mm and its elevation varies from 1950 to 3915 meter above of the sea level (mean is 2932 m). The results showed that there were 339 plant species belonging to 204 genera and 54 families of higher vascular plants (49 families were dicotyledones, 5 families were monocotyledons, 1 family was gymnosperme and 1 family was cryptogame). The family Asteraceae with 27 genera and 49 species was the largest family and the genus Astragalus (Fabaceae) with 25 species was the largest genus in the region, respectively. The genera Centaurea with 9 species, Cousinia and Salvia each with 6 species, and Polygonum, Stachys and Allium each with 5 species are the other large genera in the flora of Cahdegan region. Furthermore, 3 species were parasitic or semi- parasitic plants. Survey of the life form of the plants showed that 5% of the species were phanerophytes, 11% were chamaephytes, 44% were hemicryptophytes, 13% were geophytes and 27% were therophytes. The dominance of hemicryptophytes and therophytes (totally, 71%), indicates the severe conditions of the area which is characteristics of the mountainous regions. Phytogeographically, 64.6% of the species belonged to the Irano-Turanian region, 9.7% were pluriregional and 25.7% belonged to the other regions. Also, 29 species were endemic for the flora of Iran, 3 species were endangered, 3 species were rare, and 15 species were vulnerable.