Description from Flora of China
Quercus hainanica C. C. Huang & Y. T. Chang, invalid name; Q. obconicus Y. C. Hsu ex Z. K. Zhou.
Trees to 15 m tall; trunk to 40 cm d.b.h.; bark grayish brown. Branchlets thick, densely brown tomentose, glabrescent, lenticellate; lenticels minute, raised. Petiole 2.5-5 cm, densely brown tomentose when young but glabrescent; leaf blade elliptic, 10-20 × 5-10 cm, leathery, brown tomentose when young but glabrescent, abaxially grayish green but brownish when dry, base cuneate, margin remotely minutely serrate, apex with a short, blunt tip; midvein and secondary veins adaxially slightly raised; secondary veins 7-9 on each side of midvein; tertiary veins abaxially inconspicuous. Female inflorescences borne in axil of terminal leaf, 2-3 cm; cupules 3-5. Cupule obconic, 2-2.5 × 2.5-3.5 cm, enclosing less than 1/2 of nut, outside grayish brown tomentose, wall 3-5 mm thick; bracts in 9-12 rings, margin of basal ones entire, others denticulate and incurved. Nut ellipsoid, ca. 4.5 × 2.5-2.8 cm; scar conically convex. Fl. Dec, fr. Jun-Jul of following year.
* Mixed mesophytic forests in mountains; 900-1000 m. Hainan (Dongfang Xian)