Eco-geographical Distribution of Annual Medics Species in Iran

Iran is one of the most important centers of diversity for Medicago species. Annual medics collected from different provinces were evaluated and the relationship between their eco-geographical distribution, geographical and ecological characteristics was analysed. Results showed that annual medics were distributed mostly in the North-West, West and South of Iran. Altitude and average annual precipitation were the two important factors in distribution of annual medics in Iran. Most of the species were distributed from 0-2750 meter above sea level, in areas with 100-400mm of average annual precipitation and Mediteranean climates. Annual medics grow well in soils with pH=7.0-8.0. Soil texture analysis showed that the suitable soil for annual medics was Loam or Clay soils. Nevertheless, some species could grow in different ecological areas. Among these species M. rigidula and M. rigiduloides were adapted to cold zones, while M. laciniata and M. sauvagei were found in southern parts of Iran with 20 °C average temperature. M. littoralis is a littoral plant and grows near the Caspian Sea in the North and Persian Gulf in the South. M. noeana was also found only in North-west and West of Iran.