红马蹄草 hong ma ti cao

Hydrocotyle polycephala Wight & Arnott.

Stems robust, decumbent 5–45 cm long. Petioles 4–27 cm, distally densely pubescent; leaf blade orbicular or reniform, 2–5 × 3.5–9 cm, shallowly 5–7-lobed, thin-papery, both surfaces strigose, base cordate, palmately 7–9-nerved, lobes triangular to rounded, crenate. Umbels several to numerous, fascicled in axils and ends of stems; each umbel densely capitate, 20–60-flowered; peduncles 0.5–2 cm, shorter than petioles, puberulous; bracts ovate or obovate, minute, membranous. Pedicels very short, 0.5–1.5(–2) mm in fruit. Petals white or with purplish red stains. Stylopodium depressed; styles incurved when young, spreading in fruit. Fruit pale brown or deep purple with dark stains when mature, broadly oblate-globose, 1–1.2 × 1.5–1.8 mm. Fl. and fr. May–Nov.

Mountain slopes, shady wet grassy places, stream banks; 300–3600 m. Anhui, Guangdong, Guangxi, Guizhou, Hainan, Hubei, Hunan, Jiangxi, Shaanxi, Sichuan, Xizang, Yunnan, Zhejiang [Bhutan, NE India (Assam), Myanmar, E Nepal, Sikkim, Vietnam].

This species has reputed medicinal value. It is part of the highly variable complex of Hydrocotyle javanica Thunberg, which extends from Nepal east to Japan and south through Indonesia into Australia. The umbels fascicled at the nodes unite this group and differentiate it from other species of Hydrocotyle, but its classification is in need of revision across its whole geographic range.