Description from Flora of China
Crotalaria acuminata G. Don; C. angulosa Lamarck; C. mollis Weinmann.
Herbs, erect, 50-100 cm tall. Branches 4-angled, glabrescent. Stipules leaflike, ovate-falcate, 5-8 mm. Leaves simple; petiole 3-5 mm; leaf blade ovate to elliptic, 10-15 × 3-5 cm, thinly membranous, abaxially densely pubescent, adaxially glabrous, base broadly cuneate, apex acuminate. Racemes terminal, 10-20-flowered; bracts linear, ca. 1 mm. Pedicel 3-4 mm; bracteoles inserted apically from middle of pedicel. Calyx subcampanulate, 8-10 mm, 5-lobed; lobes lanceolate, slightly longer than tube. Corolla pale yellow, white, or often tinged blue; standard orbicular to obovate, 1-1.8 cm, base with 2 appendages; wings oblong, 1-1.6 cm; keel ± as long as wings, exserted beyond calyx, rounded with an incurved, fairly shortly twisted beak. Ovary subsessile, pilose on apical part. Legume oblong, 2-4 cm, 10-12-seeded, pubescent. Seeds nearly smooth to papillose, shiny. Fl. Aug-Oct, fr. Nov-Dec.
Crotalaria verrucosa is now quite a common weed throughout the tropics.
Grasslands, sparse forests; 100-200 m. Guangdong, Hainan, Taiwan [Bangladesh, Cambodia, Indonesia, Laos, Malaysia, Myanmar, Nepal, Philippines, Sri Lanka, Thailand, Vietnam; Australasia, introduced in Africa and the Americas].