Description from Flora of China
Mimosa pennata Linnaeus, Sp. Pl. 1: 522. 1753.
Climbers, with copious, scattered prickles. Branchlets and leaf rachis ferruginous pubescent. Stipules (ovate-)lanceolate, 3-5 × 1-1.5 cm, cuspidate; petiolar glands subpulvinate, narrowly terete or slightly obconic, 0.3-3 mm in diam., below middle of petiole, usually just above basal pulvinus and several between distal pinnae; pinnae 8-22 pairs; leaflets 30-54 pairs, densely crowded, linear, 5-10 × 0.5-1.5 mm, midvein near upper margin, base truncate, margin ciliate, apex sharply acute, asymmetric, bent forward, often nearly hooked, or apex broadly acute, straight. Heads solitary or 2- or 3-fasciculate, globose, ca. 1 cm in diam., arranged in axillary or terminal panicles; peduncles 1-2 cm, yellow pubescent or reddish glandular hairy. Flowers pedicellate or subsessile. Calyx subcampanulate, 1.5-2.5 mm, 5-toothed. Corolla 2-3.2(-4.2) mm. Ovary puberulent, stipitate. Legume strap-shaped, 9-20 × 2-3.5 cm, glabrous or finely puberulent when young, sutures slightly sinuate. Seeds black, 8-12, narrowly elliptic, 6-10 × 4.5-7 mm, flat. Fl. Mar-Oct, fr. Jul-Apr of following year.
Acacia pennata var. pennata occurs in India, Myanmar, Sri Lanka, and Thailand.
Thin forests, thickets. Fujian, Guangdong, Guangxi, ?Guizhou, Hainan, Yunnan, ?Zhejiang [Bhutan, Cambodia, India, Laos, ?Malaysia, Myanmar, Nepal, Sri Lanka, Thailand, Vietnam].