Description from Flora of China
Glycine pinnata Merrill, Lingnan Sci. J. 14: 15. 1935; Cruddasia pinnata (Merrill) Niyomdham; Paraglycine pinnata (Merrill) F. J. Hermann.
Vines. Stems twining, herbaceous or almost woody, hirsute. Leaves pinnately 5-7-foliolate, 10-15 cm; stipules lanceolate; petiole 3-6 cm; stipels filiform, ca. 1 mm, deciduous; petiolules 1-2 mm; leaflets oblong or elliptic, 2.5-7(-9) × 1.4-3.8 cm, papery, abaxial surface densely clothed with white coarse hairs, adaxial surface glabrous or sparsely clothed with coarse adpressed hairs, lateral veins 5 or 6 pairs, base rounded, apex obtuse to acuminate, sometimes with mucro. Raceme axillary, 4-10 cm; peduncles 6-10 mm. Flowers small, solitary or paired, ca. 6 mm; bracts filiform, ca. 1 mm, persistent; bracteoles filiform or linear, ca. 1 mm. Calyx membranous, 2.5-3.5 mm, 5-lobed, upper 2 lobes connate to broadly triangular, lower lanceolate, all shorter than tube. Corolla purple to pink; standard pandurate, 5.5-6 mm; wings usually narrowly elliptic, with auricles and stipe; keels oblong, equal to wings, with auricles and stipe. Ovary 2-8-ovuled. Legume oblong, 2.5-4 × 6-8 cm, compressed, apex with short beak, densely hirsute, reflexed after dehiscence. Seeds 2-5, brown or black, suborbicular, compressed, ca. 4.5 mm in diam.; strophiole dry membranous, scalelike. Fl. Jul-Aug, fr. Aug-Sep.
Open scrub; below 1200 m (in Vietnam). Hainan [Vietnam].