Description from Flora of China
Trees to 15 m tall. Branchlets puberulent, glabrescent. Petiole 5-12 mm, puberulent, glabrescent; leaf blade spatulate or obovate, 7-12 × 3-6 cm, becoming narrow from middle downward, thinly leathery, glabrous or abaxially pubescent only in vein axils, lateral veins 6-8 per side, 60° from midvein, prominently raised abaxially, inconspicuous adaxially, veinlets conspicuous abaxially, base narrow and rounded, margin sinuately crenulate in upper 1/2, apex acute. Flowers usually solitary, ca. 1.5 cm in diam. Pedicel 2-3 cm, gray pubescent. Sepals 4, broadly ovate, variable in size, 4-7 mm, puberulent, apex obtuse. Petals 4, broadly ovate, 4-7 mm, both surfaces puberulent, incised at apices. Stamens ca. 5 mm; anthers longer than filaments, pubescent. Ovary ovoid, tomentose; style simple, ca. as long as ovary, nearly glabrous. Capsule nearly globose, ca. 3.5 cm in diam., 3- or 4-valved; valves ca. 3 mm thick; prickles 1-1.5 cm. Seeds 1.5-2 cm, enclosed by aril in lower 1/2. Fl. May, fr. Jul-Aug.
● Evergreen forests; 300-500 m. C and S Hainan.