Description from Flora of China
Ophioxylon serpentinum Linnaeus, Sp. Pl. 2: 1043. 1753; O. majus Hasskarl.
Shrubs to 1 m tall, erect, glabrous. Stems usually unbranched, slender, straw colored. Leaves grouped near stem apex, in whorls of 3-5; petiole 1-1.5 cm; leaf blade narrowly elliptic or obovate, membranous, 7-17 X 2-9 cm, base cuneate, apex acuminate or rarely obtuse; lateral veins 7-15 pairs. Cymes congested; peduncle 5-13 cm, red or reddish. Pedicel and calyx red or reddish. Corolla white, tube cylindric, 1-1.8 cm, inflated at middle and pilose inside distal half; lobes obliquely suborbicular, 1.5-3.5 mm. Stamens inserted at middle of corolla tube. Ovaries connate in basal half. Drupes ellipsoid, ca. 8 mm, connate for half their length. Fl. Feb-Oct, fr. May-Dec. 2n = 22.
The roots are used as a sedative and in the treatment of hypertension. The bark, leaves, and roots are used against snake and scorpion poisoning.
Montane forests; 800-1500 m. S Yunnan (Gengma, Jing-hong), cultivated in S Guangdong, S Guangxi, Hainan [India, Indonesia, Malaysia, Myanmar, Sri Lanka, Thailand].