"Agi-nashi" (Sagittaria aginashi) belongs to the family Alismataceae (the Water-plantain family). It is a perennial herb that is native to all over Japan, as well as the Korean Peninsula and China. This herb grows in rice fields, marshes and shallow freshwater environments, and can reach about 50 cm in height. The leaves are narrow elliptic at first, and their bases divide into two lobes when aging. It resembles to Arrowhead closely, and defined that the lower lobes are shortish than the upper lobe. The flowering stalks are borne and the white flowers from August to October. The male flowers are arranged on upper stems, and the female flowers are arraged on lower stems.