Quercus longinux Hayata, J. Coll. Sci. Univ. Tokyo 30(1): 292. 1911; Cyclobalanopsis longinux var. kuoi J. C. Liao; C. longinux var. lativiolaciifolia J. C. Liao; C. longinux var. pseudomyrsinifolia (Hayata) J. C. Liao; Q. pseudomyrsinifolia Hayata; Q. taichuensis Hayata.

Trees. Branchlets glabrous, lenticellate; lenticels oblong. Petiole 1-2 cm, glabrous; leaf blade ovate-lanceolate to narrowly oblong-elliptic, 6-8 × 2-2.5 cm, abaxially farinose or with adnate simple hairs, adaxially bright green, base cuneate, margin apical 1/2 serrate, apex acuminate to caudate; secondary veins 7-9 on each side of midvein. Cupule bowl-shaped, 8-9 mm × 1-1.2 cm, enclosing ca. 1/2 of nut, outside grayish brown tomentose, wall thin; bracts in 6-8 rings, margin dentate. Nut ovoid to ovoid-ellipsoid, ca. 1.2 × 0.9 cm; scar convex; stylopodium persistent, short. Fl. Mar-May, fr. Sep-Nov.

* Broad-leaved evergreen forests in mountains; 300-2500 m. Taiwan