Description from Flora of China
Trees, (8-)10-17 m tall; old branches yellowish brown with vertical stripes, glabrous. Leaves trifoliolate, rarely 5-foliolate; rachis 4-7 cm, glabrous, grayish brown; terminal petiolule (1-)2.5-3.5 cm, lateral ones 2-3 mm or lateral leaflets sessile; leaflet blades oblong-oval to elliptic, (6-)8-10 × (2.5-)3.5-4.5 cm, papery, glabrous and dark green adaxially, slightly pubescent along veins near base of blade and pale green abaxially, veins conspicuous on both surfaces, lateral veins 6 or 7 pairs, base broadly cuneate, margin serrate, slightly revolute, apex acuminate. Inflorescence an axillary raceme, flowering before foliage, bracteoles linear. Flowers 9-12 mm; pedicel 4-5(-8) mm. Sepals linear-deltoid, 7-9 × ca. 4 mm, glabrous or exterior slightly pubescent at base. Petals spatulate, ca. 9 mm, glabrous, inserted at disk margin. Stamens alternate to petals; filaments ca. 7 mm, base glabrous; anthers ca. 2 mm. Ovary 1-locular, with numerous ovules per locule; styles 3, ca. 7 mm including ovary, base slightly pubescent; stigma capitate. Capsules 4.5-6.5 × 2-3.5 cm, columnar to campanulate, base rounded. Seeds 5-7 mm in diam., shining, olive green to yellow. Fl. May, fr. Aug.
● Open forests on slopes; 2300-2700 m. N Guangdong (Ruyuan), Guizhou, S Sichuan (Huidong), Yunnan (Songming).