Trees , to 46 m. Bark light gray, fissured or exfoliating, separating freely into long strips or broad plates that persist, ends often curling away from trunk. Twigs greenish, reddish, or orangish brown, retaining color or turning black on drying, stout or slender, hirsute or glabrous. Terminal buds tan to dark brown to black, ovoid, 6-18 mm, tomentose or nearly glabrous; bud scales imbricate; axillary buds protected by bracteoles fused into hood. Leaves 3-6 dm; petiole 4-13 cm, petiole and rachis hirsute or mainly glabrous. Leaflets (3-)5(-7), lateral petiolules 0-1 mm, terminal petiolules 3-17 mm; blades ovate, obovate, or elliptic, not falcate, 4-26 × 1-14 cm, margins finely to coarsely serrate, with tufts of hairs in axils of proximal veins of serrations, often weathering to only a few in fall, apex acute to acuminate; surfaces abaxially hirsute with unicellular and 2-4-rayed fasciculate hairs, occasionally restricted to midrib and major veins or essentially without hairs, with few to many large peltate scales and small round, irregular, and 4-lobed peltate scales. Staminate catkins pedunculate, to 13 cm, stalks and bracts without hairs; anthers hirsute. Fruits brown to reddish brown, spheric to depressed-spheric, not compressed, 2.5-4 × 2.5-4 cm; husks rough, 4-15 mm thick, dehiscing to base, sutures smooth; nuts tan, ovoid, obovoid, or ellipsoid, compressed, 4-angled, rugulose; shells thick. Seeds sweet. Native Americans used Carya ovata medicinally as an antirheumatic, a gynecological aid, a tonic, and an anthelmintic (D. E. Moerman 1986).

Carya ovata hybridizes with C . cordiformis ( C . × laneyi Sargent), C . illinoinensis , and C . laciniosa ( C . × dunbarii Sargent). The Mexican shagbark appears to be a good variety.

The Mexican hickory ( Carya ovata var. mexicana (Hemsley) W. E. Manning) appears to be synonymous with C . ovata .