"Aze-naruko" (Carex dimorpholepis) belongs to Cyperaceae (the Sedge family). It is a perennial herb that is distributed widely westward from Honshu to Shikoku, Kyushu of Japan, as well as the Korean Peninsula, China and the Indochina Peninsula. This herb grow in rice field linches or marshes, and can reach 40-70 cm in height. The 4-7 drooping spikes are borne on the terminal flowering stalks from April to June. The acrogyrous spike is bisexual, it consists of the female apical part and the male basal part. The other spikes are female.