XVI International Botanical Congess

Critical checklist of arctic Leguminosae was compiled, showing the distribution of species between 23 areas of «Panarctic flora». Legumes are absent in 6 of the 23 (Atlantic Sector) and in northern islands of 4 others (lack of polinators: bumble-bees). Centres of their species diversity lie in Megaberingia: W Beringia (48), E Siberia (39), E Beringia (36). Of the total 108 sp native to Arctic, 26 are stenochoric endemics (1-3 areas), 19 - stenochoric subendemics (mostly metaarctic endemics), 40 - other stenochoric differential taxa, which could be explained by allopatric speciation (+polyploidy). In its species composition of legumes, W Beringia is similar to E Siberia by 51.1% (Soerensen index), to E Beringia by 49%. Generic diversity is low - 8, of which Oxytropis (64 sp: 5 sections), Astragalus (27:11), Hedysarum (7:2) are constant. Only Oxytropis showed intensive speciation in 4 sections. The formation of arctic legumes compri-sed besides Arctic also subarctic low and high elevation areas, being little dependent on southern alpine floras.