Description from Flora of China
Hedysarum triquetrum Linnaeus, Sp. Pl. 2: 746. 1753; Desmodium acrocarpum Hance; D. triquetrum (Linnaeus) Candolle; Pteroloma triquetrum (Linnaeus) Desvaux ex Bentham.
Shrubs or subshrubs. Stem erect, 1-2 m tall. Leaves 1-foliolate; petiole 1-3 cm, wing 4-8 mm wide; blade narrowly lanceolate to ovate-lanceolate, 5.8-13 × 1.1-3.5 cm, usually more than 3 × as long as wide, abaxially pubescent on midvein and lateral veins, adaxially glabrous, base rounded or shallowly cordate, apex acute or acuminate. Inflorescences 15-30 cm, 2- or 3-flowered at each node. Pedicel 2-6 mm, with spreading, minute, hooked and silky hairs. Calyx broadly campanulate, ca. 3 mm. Corolla pink to bluish or reddish purple, 5-6 mm; standard nearly orbicular, emarginate at apex; wings obovate, auriculate, clawed; keel arcuate, auriculate, clawed. Stamens diadelphous. Ovary densely puberulent except at upper part of style. Legume 5-8-jointed; articles not reticulate veined, densely yellowish or whitish strigose. Seed transversely broadly elliptic or elliptic, 2-3 × 1.5-2.5 mm. Fl. Jun-Oct, fr. Oct-Dec. 2n = 22.
The whole plant is used medicinally as an antipyretic, as a diuretic, for invigorating the spleen, and for promoting digestion.
Wastelands, forest margins, roadsides; below 1400 m. Fujian, Guangdong, Guangxi, Guizhou, Hainan, Jiangxi, Taiwan, Yunnan [Bangladesh, Bhutan, Cambodia, India, Indonesia, Japan (Ryukyu Islands), Laos, Malaysia, Myanmar, Nepal, New Guinea, Philippines, Sri Lanka, Thailand, Vietnam; ?N Australia, Pacific islands].