The "Kasa-suge" (Carex dispalata) belongs to Cyperaceae (the Sedge family). It is a perennial herb that is distributed to all over Japan. This herb grows in wet places in lowland by ponds or rivers and can reach 40-100 cm in heght. It has thick rootstocks, speads by stolons and forms clumps. The stems are triquetrous, the leaves are hard and linear. The 4-7 spikelets are borne on upper stems from April to July. The acrogyrous spikes are male, brown and linear. The pleurogerous spikes are female and columnar. The leaves had been used to make straw raincoats and straw hats.