扁果青冈 bian guo qing gang

Quercus chapensis Hickel & A. Camus, Bull. Mus. Natl. Hist. Nat. 29: 598. 1923; Cyclobalanopsis koumeii Hu; C. shiangpyngensis Hu.

Trees to 20 m tall. Branchlets sulcate, villous or glabrous when young, lenticellate; lenticels grayish brown, oblong. Petiole 1-2.5 cm, glabrous; leaf blade oblong-elliptic to lanceolate, 9-20 × 2-4(-5) cm, leathery to thickly papery, glabrescent, base broadly cuneate to subrounded, margin apical 2/3 serrulate, apex acuminate; midvein and secondary veins abaxially prominent, adaxially slightly raised; secondary veins 15-20 on each side of midvein; tertiary veins abaxially conspicuous. Cupule saucer-shaped, 5-12 mm × 2.5-3.5 cm, covering base of nut, outside sparsely orangish brown tomentose, inside orangish brown sericeous, wall 3-5 mm thick; bracts in 6-9 rings, margin dentate. Nut oblate, 1-2.2 × 1.5-2.7 cm, glabrous or basally pilose, base flat, apex rounded to slightly depressed; scar ca. 1.5 cm in diam., flat or depressed; stylopodium ca. 3 mm in diam., umbonate. Fr. Oct-Dec.

Wet broad-leaved evergreen forests in mountain valleys; 1300-2000 m. S to SE Yunnan [Vietnam]