Study of the genus Euphorbia and importance of its species in Iran with emphasis on biodiversity and their conservation status in the country

Euphorbia (Euphorbiaceae) with more than 2000 species is the second largest giant genus distributed throughout the continent except the Arctic. Iran with four subgenera, 19 sections, three subsections, and 93 species is the second richest country after Turkey and one of the most important biodiversity centers in west Asia. Iran, is the richest concentration of endemic and subendemic Euphorbia species among West Asian countries with 21 and 33 species, respectively. Four northern provinces of Iran viz. Mazandaran, Khorasan, Alborz, and Eastern Azarbaijan, are the most diverse ones with 30, 27, 26, and 26 species, respectively. The lowest diversity of the genus with six and eight species occur in Qom and Bushehr provinces, respectively. The highest number of endemics was observed in Esfahan and Fars with eight and seven species, respectively, followed by Kerman, Khorasan and Mazandaran provinces with five species each. There is no endemics in Qom and Kermanshah provinces. All endemic and subendemic species in Iran were evaluated by the IUCN Red List categories and criteria. Of the 60 known evaluated species at the country level, 27 species was classified under threatened categories including, CR, EN, and VU with nine species each. The 33 remaining species were considered as NT and LC with three and 30 species, respectively.