Introduction of the flora, life form and chorology of Helen protected area in Chaharmahal and Bakhtiari province

Each region''s flora is as a result of communities'' reactions to the current environmental conditions and plant evolution in the past. This aim of this study is to introduce floristic list، life form and endangered species of Helen region. This region covers about 40231 ha and lies in the west part of Chaharmahal and Bakhtiari province. The results showed that 392 plant species existed in the region belonging to 67 families and 267 genera. The families Compositae، Labiatae and Papilionaceae with 60، 37 and 34 species embraced higher species respectively. The genus Astragalus with 15 species was the largest genus in the region. According to Raunkiaer’s life form، species followed as: 43. 88% hemicryptophytes (172 species)، 22. 96% therophytes (90 species)، 14. 03% cryptophytes (55 species)، 7. 44% phanerophytes (37 species) and 8. 93% chamephytes (35 species). The chorology of species showed that 64. 80 percent of species belonged to Irano-Turanian، 6. 12 percent Polyregional، 3. 32 percent Cosmopolitan and the rest to the others. Threatened species included 70 totally belonging to Irano-Turanian. Among which them the endangered class، vulnerable، lower risk and data deficient were 3، 3، 55 and 9 species respectively.