"Oo-marubano-horoshi" (Solanum megacarpum) belongs to the Solanaceae (the Nightshade family). It is a perennial herb that is distributed eastward from Hiroshima prefecture in Hoanshu to Hokkaido, the sothern Kuril Islands and Sakhalin. This herb grows in forest edges, marshes or streamsides, and can reach 30-70 cm in height. The leaves are ovate to narrow ovate, arranged oppositely with entire edges. The cymes are borne and the pale purple flowers bloom from July to September. The corolla is divided deeply into five lobes. The fruits are poisonous berries and ripen red.