Trees to 10(-25) m tall. Bark pale gray-brown; branches lenticellate. Petiole short or absent; leaf blade obovate-oblong or obovate-elliptic, 7-41 X 3-20 cm, base cuneate or decurrent, apex obtuse or acute, glabrous on both surfaces or pubescent abaxially; lateral veins 8-22 pairs. Cymes 6-25 cm, usually many flowered. Calyx 0.7-1.9 cm, lobes broadly ovate to oblong. Corolla yellow or white, tube 0.7-1.5 cm, twisted; lobes obovate or elliptic, recurved, twisted in bud. Follicles obliquely subglobose, with pale green spots. Seeds dark brown, obliquely ellipsoid, 7-10 X 3.5-5 mm. 2n = 22.

S Yunnan [introduced from W Africa].