The first record of Astragalus sect. Aegacantha (Fabaceae) in Iran

A new distinct population of Astragalus leiosemius, hitherto unknown to science, is reported for the first time from the eastern Alborz mountains in the Irano-Turanian part of Iran, at an altitude of 2400 m, far disjunct (ca. 800 km) from the populations at the Asia media and Afghanistan. The new taxon is described and illustrated as Astragalus leiosemius subsp. sabzevarensis. This orophilous and tragachantic plant belongs to A. sect. Aegacantha. On the basis of some important data on morphology, ecology and chorology, the new taxon is reported and its affinities and differences with regard to close taxa are presented. A. sect Aegacantha is recorded for the first time from the eastern part Iran.