"Tsukushi-oo-gayatsuri" (Cyperus ohwii) belongs to Cyperaceae (the Sedge family). It is a perennial herb that is widely distributed in southeastern Asia. It was probably introduced in Kyushu of Japan. Now, it is distributed to Fukuoka, Ooita prefecture in Kyushu and Chiba, Ibaraki prefecture in Honshu. This herb grows in lowland wetlands and up to a height of 1-1.5 m. The stems are thick, triquetrous and crowded. The leaves are linear 1-1.5 cm wide. The many spikelets are borne on the cluster-branches atop of stems and ripen in September and October. The terrestrials are blighted and pass the winter in the rhizome.