Description from Flora of China
Crotalaria leschenaultii Candolle; C. sericea Retzius (1788), not N. L. Burman (1768), nor Willdenow (1802).
Herbs, erect, 0.6-1.5 m tall. Branches terete, glabrous. Stipules ovate-triangular, ca. 1 cm. Leaves simple; petiole 2-8 mm; leaf blade oblanceolate to narrowly elliptic, 7-15 × 2-5 cm, thin, abaxially appressed silky pubescent, adaxially glabrous, base broadly cuneate, apex obtuse and mucronate. Racemes terminal, 20-30-flowered; bracts ovate-triangular, 7-10 mm. Pedicel 1-1.5 cm; bracteoles inserted at or apical to middle of pedicel, linear, ca. 1 mm. Calyx 2-lipped, 1.2-1.5 cm, glabrous; lobes broadly lanceolate-triangular, longer than tube. Corolla pale yellow; standard veined purplish red, suborbicular to oblong, 1-2 cm, base with 2 appendages, apex obtuse to retuse; wings obovate, ca. 2 cm; keel rounded about middle, with a fairly short and slightly incurved twisted beak exserted beyond calyx. Legume broadly oblong, 2.5-3 × 1.5-2 cm, 20-30-seeded, shortly stipitate, glabrous. Seeds smooth. Fl. Aug-Oct, fr. Oct-Dec.
Montane grasslands, along trails; 100-1500 m. Anhui, Fujian, Guangdong, Guangxi, Hunan, Jiangsu, Jiangxi, Taiwan, Yunnan, Zhejiang [Bangladesh, India, Malaysia, Myanmar, Nepal, ?Philippines, Thailand; cultivated and naturalized in Africa and Madagascar].