Description from Flora of China
Callerya pachyloba (Drake) H. Sun; Derris lasiopetala Hayata; Millettia lasiopetala (Hayata) Merrill; M. obovata Gagnepain; M. pachyloba var. lasiopetala (Hayata) P. K. Lôc.
Lianas, to 20 m. Bark yellow, splitting longitudinally. Branches straight, hollow, densely brown sericeous, glabrescent, sparsely scattered with large lenticels. Leaves 9-foliolate; rachis 25-35 cm, including petiole 6-8 cm; stipels acicular, ca. 3 mm; leaflet blade elliptic-oblong to obovate-oblong, 7-17 × 3-5.5 cm, papery, abaxially yellow sericeous, secondary veins 13-17 on each side of midvein, base rounded, apex acute to obtuse and sometimes emarginate. Pseudoracemes axillary near apex of branchlets, 20-30 cm, brown sericeous; rachis nodes with 3-7 flowers clustered on a 4-5 mm spur. Pedicel 2-3 mm. Flowers 1.2-1.5 cm. Calyx ca. 3 × 4-5 mm, sericeous. Corolla lilac; standard without basal calluses, outside sericeous. Ovary sericeous, with 4-6 ovules. Legume rhomboid-oblong, 5-8 × 3-4 cm, inflated, woody, yellow tomentose, base rounded, apex beaked. Seeds 1-4 per legume, dark brown, ovoid, shiny, 1.8-2 × ca. 1.5 cm. Fl. Apr-Jun, fr. Jul-Nov.
Millettia pachyloba is represented in China by the typical variety. Another variety, Millettia pachyloba var. spireana (Gagnepain) P. K. Lôc, occurs in Cambodia, Laos, Thailand, and Vietnam.
Evergreen broad-leaved forests in valleys; below 1500 m. Guangdong, Guangxi, SW Guizhou, Hainan, SW Hunan, Yunnan [Vietnam].