1. Pollia japonica Thunberg, Fl. Jap. 138. 1784.
杜若 du ruo
Herbs perennial. Stems erect or ascending, 30--50 cm × 3--8 mm, puberulent. Leaves sessile or base attenuate into winged petiole; leaf sheaths glabrous; leaf blade narrowly elliptic, 10--30 × 3--7 cm, subglabrous and scabrous adaxially, glabrous abaxially. Inflorescence much longer than distal leaves; peduncle 15--30 cm, puberulent; cincinni numerous, 2--4 cm, often in several distant whorls, some in panicles, puberulent; involucral bracts lanceolate, puberulent; bracts membranous. Sepals ovate-orbicular, ca. 5 mm, glabrous, persistent. Petals white, obovate-spatulate, ca. 3 mm. Stamens 6, all fertile, rarely staminodes 1 or 2 with shorter filaments. Fruit globose, ca. 5 mm in diam. Fl. Jul--Sep, fr. Sep--Oct.
Forests in ravines; near sea level to 1200 m. SE Anhui (Huang Shan, Xiuning Xian), Fujian, N Guangdong, Guangxi, Guizhou, SW Hubei (Laifeng Tujia Zu Zizhixian, Xuan’en Xian), Hunan, Jiangxi, SE Sichuan (Pengshui Xian), Taiwan, Zhejiang [Japan, Korea].
The root has sedative, stimulant, and carminative properties, and is used for the treatment of colds and vertigo.