"Itachi-sasage" (Lathyrus davidii) belongs to Fabaceae (the Pea family). It is a perennial herb that is distributed throughout Japan, the Korean Peninsula, and northeastern China. It grows in sunny grasslands in mountainous areas and grows to a height of about 120 cm. The leaves are 2-4 times pari-pinnate compound, alternate. Butterfly-shaped flowers bloom from July to August in inflorescences that extend from the leaf axils. The flowers are yellow at first, but eventually turn brown. The Japanese name comes from the color of the flower, which resembles the color of weasel hair. In Chinese, it is called "大山黧豆" (da shan li dou).