Abstract
Oxytropis megalantha H. Boiss. (Leguminosae) is an endemic species in Rebun Island, Hokkaido. It is listed in the red data book published by Environment Agency and Hokkaido, as "Critically Endangered" and "Endangered", respectively. Effects of temperatures and sulfuric treatment on germination were investigated in an incubator. Since seeds have a physical dormancy, non–treated seeds show the germination of about 10% or less. Treatment with concentrated sulfuric acid for 10–40 min caused cracks or cavities on the seed coat and water absorption became possible, then a high germination rate was attained within 10 days after sowing. Non–dormant seeds treated with sulfuric acid germinated to 71–77% at wide temperature range of 10–30°C, 10 days after sowing. Individuals came to flower from late May to mid–August next year, when seeds treated with sulfuric acid were sown in late May, seedlings were transplanted in the pot, and they were grow in the green house.
