"Shira-suge" (Carex doniana) belongs to Cyperaceae (the Sedge family). It is a perennial herb that is distributed not only in various parts of Japan, but also in the Korean Peninsula, China, Taiwan, Malaysia Peninsula and India. It grows in wetlands on flatlands to mountainous and can reach a height of 50 to 70 cm. The stem has three ridges and linear leaves alternate. The underside of the leaves have densely papillae and appear whitish. From April to June, 4 to 6 spikelets are borne to the top of the stem. The acrogyrous spikes are male and the pleurogerous spikes are female. The Japanese name is because the back of the leaf is white. It is also known as "Musha-naruko-suge" in Japan.