Flora, life forms and chorotypes of plants in south of Birjand

The present study was carried out in the south of Birjand, Center of South Khorasan province, with approximately area 1200km2 & highest altitude, is 2595 m in Bagheran range & lowest altitude 1461 m in Birjand plain. In this study, totally 300 species of 228 genera in 50 families, in two vegetation seasons, in Central Herbarium of Tehran University-Faculty of Science (TUH), were recognized. 1 species belong to Adiantaceae, 1 species to Ephedraceae and the others to Angiosperms. Among these families represented in the area, the following families have the highest number of species: Asteraceae (48 species), Brassicaceae (33 species), Poaceae (23 species), Apiaceae(23 species), Fabaceae (16 species) and Lamiaceae (13 species), Chenopodiaceae & Boraginaceae (11 species), Caryophyllaceae (10 species). The highest genus is Astragalus (6 species), in addition, the study of chorology indicated that the most plants belonged to the Irano- Turanian (143 spp.) & Euro-Siberian - Irano-Turanian – Mediterranean (26 spp.) & least plants belonged to Irano- Turanian – Irano-sendian (3 spp.) & Irano-Turanian – Mediterranean- sahara-sendian (3 spp.) chorotypes & 12 species are cosmopolitans & 16 species are Endemics. Among 300 recognized species of this region, based on Ranckaer s classification, the high frequency of Therophytes with 144 species (48%), Hemichryptophyes with 49 species (16.3%) & Chamaephytes with 43 species (14.3%), Geophytes with 36 species (12%), Nanophanerophytes with 15 species (5%), Phanerophytes with 6 species (2%), Helophytes with 3 species (1%), Hydrophyte with 1 species(0.33%).

Keywords:

Endemic , Bagheran range , South Khorasan