Shrubs or subshrubs, erect or prostrate, 30-150 cm tall, much branched from base of stem. Leaves 3-foliolate; petiole 1-2 cm, slightly pubescent; terminal leaflet blade elliptic, nar­rowly elliptic, or broadly obovate, 2.5-6 × 1.3-3 cm, abaxially white adpressed pubescent, adaxially glabrous, base obtuse, apex rounded or obtuse, emarginate, mucronate. Racemes ter­minal or axillary, 2.5-7 cm; rachis with white, spreading, hooked hairs or yellowish or white, straight, appressed hairs, densely flowered. Pedicel 3-4 mm. Calyx 1.5-2 mm, 4-lobed; upper lobes slightly 2-toothed at apex. Corolla purple, purple-red, or white, ca. 5 mm; standard obovate-oblong, shortly clawed; wings obovate, auriculate, clawed; keel extremely curved, apex obtuse. Infructescence crowded. Legume erect, narrowly oblong, 1.2-2 cm × 2.5-3 mm, upper suture shallowly undulate, both sutures hooked hairy, 4-7-jointed; articles quad­rate. Fl. Jul-Oct, fr. Oct-Dec. 2n = 22*.

We (Huang and Ohashi) differ in our circumscriptions of Des­modium heterocarpon. One of us (Ohashi) recognizes eight infraspecific taxa, including D. heterocarpon subsp. angustifolium H. Ohashi, which corresponds to D. reticulatum in this treatment, and D. heterocarpon subsp. heterocarpon, comprising var. heterocarpon and var. strigosum (see J. Jap. Bot. 66: 14-25. 1991).

Grasslands, grassy slopes, watersides, thickets, forests; 300-1800 m. Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hubei, Hunan, Jiangsu, Jiangxi, Sichuan, Taiwan, Yunnan, Zhejiang [Bhutan, Cam­bodia, India, Indonesia, Japan, Laos, Malaysia, Myanmar, Nepal, Philip­pines, Sri Lanka, Thailand, Vietnam; Africa, Australia, Pacific islands].