XVI International Botanical Congess

The genus Astragalus L. is the biggest one in Southern Transcaucasia: about 125 species from 9 subgenera and 39 sections. Southern Transcaucasia is one of the largest centers of origin of the genus in South-West Asia. Here grow 26 highly local species, 20 species occur, except Southern Transcaucasia, in the adjacent regions of Turkey and Iran. Most species grow at the altitude 1,000-2,000 m above sea level. They occur in semi-desert, steppe, steppe-meadow landscapes, as well as in open woodlands, and are common in thinned out phryganoid xerophyte formations (mountain-xerophytes"). According to the geographical distribution the main part of the genus species in the region belongs to the Irano-Turanian species group.