Bunchy flatsedge (Cyperus polystachyos) belongs to Cyperaceae (the Sedge family). It is a perennial herb that is dstributed westward from Kanto district of Honshu to Shikoku, Kyushu, the Ryukyu Islands, and as well as Taiwan, the southern Korean Peninsula and sub-tropical to tropical areas throughout the world. This herb grows in coastal sandy places or grasslands, and can reach 10-40 cm in height. The stems are very hard and clumping, and the leaves are linear. The flowering stalks are borne and produce globose inflorescences at the top of stalks from August to October. The spikelets are flat linear-lanceolate with acute tips. The several, long leafy bracts are borne at the base of inflorescences.