Description from Flora of China
Caesalpinia aestivalis Chun & F. C. How; Pterolobium indicum Hance; P. rosthornii Harms.
Climbers, woody, or climbing shrubs, 3-10 m tall. Branchlets angular, silvery white puberulent and light yellow hairy when young, glabrescent when old, with blackish, recurved, short prickles scattered or in pairs at bases of petioles. Leaf rachis 12-20 cm; petiole 3-5 cm, with paired blackish stipulaceous spines; pinnae 9-14 pairs, long and narrow; rachis of pinnae 5-8 cm, sulcate; petiolules short, articulate; leaflets 19-30 pairs, opposite, narrowly oblong, blades at middle 9-10 × 2-2.5 mm, both surfaces yellowish hairy, abaxially denser, abaxially with conspicuous or obscure blackish dots, veins obscure, base slightly oblique, apex rounded-cuspidate or emarginate. Racemes 8-13 × 1.5-2.5 cm, puberulent, supra-axillary or at apices of branches forming a panicle; bracts setiform, 3-5 mm. Pedicels 2-4 mm, slender, spaced at intervals of 1-2 mm. Flower buds obovoid, ca. 4.5 mm, tomentose. Sepals: lowest one longer, navicular, ca. 4 mm, ciliate; others oblong, ca. 3 mm. Petals equal, slightly longer than calyx, obovate, apex slightly praemorse. Stamens equal in length, exserted; filaments 5-6 mm, pubescent from middle downward; anthers broadly ovoid, ca. 1 mm. Ovary compressed, ciliate on one side, 2-ovuled; style glabrous; stigma funnel-shaped. Legume shiny, 4-6 cm, part containing seed rhomboid, 1.6-2 × 1-1.3 cm, wings straight on one side and curved on other side, 3-4 × 1.3-1.5 cm, with persistent style. Seed solitary, elliptic, ca. 8 mm. Fl. Jun-Aug, Oct, fr. Apr, Sep-Jan.
Sparse forests, sunny slopes, dry rocky hills, near roads, limestone mountains; 300-2000 m. Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hubei, Hunan, Jiangsu, Jiangxi, Sichuan, Yunnan, Zhejiang [Laos].