Quercus polymorpha Schltdl. & Cham.  

Global Range: Northern Mexico to Guatemala and just into the U.S. in one small grove in southwest Texas (FNA 1997).

Trees , subevergreen, to 20 m. Bark gray to brown, scaly. Twigs reddish brown, 2-3 mm diam., tomentose, soon glabrate. Buds reddish brown, ovoid, 3-10 mm, apex acute, pubescent or glabrate. Leaves: petiole (6-)15-25 mm. Leaf blade elliptic or ovate or lance-ovate, sometimes obovate, 50-100(-150) × 30-60(-80) mm, base rounded or cordate, margins entire or obscurely or prominently serrate-toothed in distal 1/3 blade, revolute, secondary veins moderately curved, 10-12(-14) on each side, apex rounded, acuminate or retuse, sometimes with prominent drip-tip; surfaces abaxially light green, sometimes rather glaucous, veinlets raised, forming raised reticulum, floccose or tomentose with erect, golden hairs, soon glabrate, adaxially dark or light green, glossy, floccose or tomentose when immature, soon glabrate, secondary and tertiary veins impressed. Acorns 1-2 on peduncle 5-30 mm; cup hemispheric or funnel-shaped, 10-13 mm deep × 12-20 mm wide, including ca. 1/2 nut, scales appressed, thickened basally, gray-canescent; nut light brown, ovoid-ellipsoid or barrel-shaped, 14-20(-25) × 8-13 mm, glabrous. Cotyledons distinct.

Riparian forest gallery, margins of thorn scrub, dry tropical forest, lower margins of oak-pine woodland, and cloud forest; 400-2100m.

United States

Rounded National Status Rank: N1 - Critically Imperiled