Description from Flora of China
Hedysarum lutescens Poiret in Lamarck, Encycl. 6: 417. 1805; Desmodium lutescens (Poiret) Candolle; D. viride Vogel; Phaca trifoliata Linnaeus, nom. utique rej.; Pycnospora hedysaroides R. Brown ex Wight & Arnott; P. nervosa Wight & Arnott.
Plants 15-60 cm tall. Stem erect or procumbent, branched from base of stem. Branchlets gray pubescent. Petiole ca. 1 cm, gray pubescent; terminal leaflet blade obovate or obovate-oblong, 1.2-3.5 × 1-2.5 cm, lateral veins 4-7 on each side of midvein, distinctly reticulate veined, both surfaces densely appressed pubescent, base cuneate or slightly cordate, apex rounded or emarginate; lateral leaflets often smaller or sometimes absent. Racemes 3-6 cm, 2-flowered at each node. Pedicel 2-4 mm, gray pubescent. Calyx ca. 2 mm; lobes narrowly triangular, pubescent. Corolla ca. 4 mm. Ovary pubescent. Legume black when mature, 6-10 mm, turgid, transversely veined, slightly hairy, lower suture distinctly prominent, along upper suture dehiscent. Seeds reniform-elliptic, ca. 2 mm. Fl. and fr. Aug-Sep.
This species is planted for soil conservation and green manure.
Grassy slopes on mountains, plains; sea level to 1300 m. ?Fujian, Guangdong, Guangxi, SW Guizhou, Hainan, S Jiangxi, Taiwan, Yunnan [Cambodia, India, Indonesia, Laos, Myanmar, New Guinea, Philippines, Thailand, Vietnam; E Australia].