Description from Flora of China
Catalpa henryi Dode; C. kaempferi Siebold & Zuccarini.
Trees ca. 15 m tall; young branches sparsely pubescent. Leaves opposite or nearly so, sometimes whorled; petiole 6-18 cm; leaf blade broadly ovate, ca. 25 X 25 cm, scabrous, sparsely pubescent, or glabrescent, base cordate, margin entire or sinuolate, usually 3-lobed, apex acuminate; lateral veins 4-6 on each side of midrib, palmately 5-7-veined basally. Inflorescences paniculate, terminal; peduncle sparsely pubescent, 12-28 cm. Calyx bilabiate, 6-8 mm. Corolla campanulate, pale yellow, yellow 2-striate and purple spotted at throat, ca. 2.5 X 2 cm. Anthers divergent. Style filiform; stigma 2-lobed. Capsule linear, nodding, 20-30 cm X 5-7 mm. Seeds long ellipsoid, 6-8 X ca. 3 mm, villous at both ends. Fl. May-Jun, fr. Aug-Oct. 2n = 40*.
The fruit are used medicinally for promoting diuresis.
* Slopes; (500-)1900-2500 m. Anhui, Gansu, Hebei, Heilongjiang, Henan, Hubei, Jiangsu, Jilin, Liaoning, Nei Mongol, Ningxia, Qinghai, Shaanxi, Shandong, Shanxi, Sichuan, Xinjiang [introduced elsewhere].