18. Desmodium reticulatum Champion ex Bentham, Hooker’s J. Bot. Kew Gard. Misc. 4: 46. 1852.
显脉山绿豆 xian mai shan lü dou
Desmodium heterocarpon (Linnaeus) Candolle subsp. angustifolium H. Ohashi.
Subshrubs, erect, 30-60 cm tall. Leaves 3- or sometimes 1-foliolate near lower stem; petiole 1.5-3 cm, sparsely hairy; terminal leaflet blade narrowly ovate or ovate-elliptic to narrowly elliptic, 3-5 × 1-2 cm, lucid, abaxially adpressed pilose, adaxially glabrous, base slightly cordate, both ends obtuse or apex acute. Racemes terminal, 10-15 cm or longer; rachis densely hooked hairy, remotely 2-flowered at each node. Pedicel ca. 3 mm, glabrous. Calyx 4-lobed; lobes ca. as long as tube. Corolla pink or blue, ca. 6 mm; standard ovate-orbicular; wings obovate-oblong, wings and keel distinctly curved. Legume oblong, 1-2 cm × ca. 2.5 mm, subglabrous or hooked pubescent, lower suture undulate, upper suture straight, 3-7-jointed. Fl. Jun-Aug, fr. Sep-Oct.
Thickets, grassy slopes; 200-1300 m. Guangdong, Guangxi, Hainan, S Yunnan [Myanmar, Thailand, Vietnam].
This is a species similar to Desmodium heterocarpon but differs by the terminal leaflets usually narrowly elliptic, narrower, thicker, lucid adaxially, and the inflorescences longer and laxly flowered. One of us (Ohashi) considers it to be a subspecies of D. heterocarpon due to fundamental similarity in having erect or ascending loments comprising quadrate articles of 2.5-3 mm.