A contribution to flora, life form and chorology of plants of political boundary mountains of Arzaneh - Taybad, Khorassan-e Razavi

The current investigation concerns the flora of a political boundary mountainous area of Arzaneh، 70 km northwest of Taybad، Khorassan-e Razavi province. A total of 255 plant species belonging to 51 families and 186 genera were identified during 2011 and 2012. Hemicryptophytes (37. 5%)، therophytes (32. 8%)، geophytes (14. 8%)، chamaephytes (9. 8%) and phanerophytes (4. 7%) constitute the life form spectrum of the study area. From a chorological point of view، Irano-Turanian elements were dominant chorotypes (55. 9%) and the rest of plants were related to one، two، three or various other phytogeographical regions. The area comprises 31 Iranian endemic species. According to IUCN conservation categories، seven species of the area were classified as vulnerable (VU) and lower risk (LR) in Iranian red data list.