Description from Flora of China
Mitrephora leiocarpa W. T. Wang, Acta Phytotax. Sin. 6: 207. 1957.
Trees to 5 m tall, glabrous except for flowers. Branches lenticellate. Petiole 6-10 mm, ca. 2 mm thick; leaf blade obovate-oblong to sometimes oblong, 6-29 × 4.5-9 cm, papery, secondary veins 9-18 on each side of midvein, base cuneate to broadly cuneate, apex shortly acuminate to acute. Inflorescences axillary, 2-flowered. Flowers ca. 1.6 cm. Pedicel ca. 1.5 cm, puberulent, bracteolate at base. Sepals broadly ovate, ca. 5 mm, outside sparsely puberulent, inside glabrous. Petals reddish yellow; outer petals ovate, 1.8-2.3 × 1.1-1.5 cm, thickly leathery, outside sparsely puberulent, inside rust-colored tomentulose, base shortly clawed, apex acute; inner petals obovate, ca. 1.3 × 0.8 cm, leathery, outside glabrous, inside pubescent, base with a ca. 3.5 mm claw, margin densely pubescent, apex acute. Stamens ca. 1.5 mm; connectives apically truncate. Carpels ca. 18, linear, ca. 4 mm, glabrous; ovules 10 per carpel, in 2 series; styles clublike, as long as ovaries. Monocarps solitary or several fasciculate, ovoid, 4-7 × 2.2-4.2 cm, glabrous. Seed 1 per monocarp, reniform, 2.5-3 × ca. 2 cm. Fl. May-Jul, fr. Aug-Nov.
● Forested slopes; 700-1600 m. S Yunnan.