The "Oku-torikabuto" (Aconitum japonicum) belongs to Ranunculaceae (the Buttercup family). It is a perennial herb that is endemic to Japan and distributed northward from Chubu district in Honshu to southern Hokkaido. This herb grows in wettish forest floors of montane beech forests and along montaine streams, and can reach 1-2 m in height. The stems are scendent at the forest edges and erect at the grasslands. The leaves are divided into 5-7 lobes. They are not divided more fine lobes. The flowers are dark purple and helmet-shaped, and bloom August to October. The Japanese name comes from its abundance in Michinoku (Tohoku district).