Trees , deciduous, to 20 m. Bark light gray, tinged with red, with thick plates underlying scales. Twigs grayish or reddish, (2-)3(-4) mm diam., villous, soon glabrate. Buds 3 mm, gray-puberulent. Leaves: petiole 8-20(-25) mm. Leaf blade obovate or broadly obovate, 100-160(-200) × 50-100(-120) mm, base narrowly cuneate to acute, margins moderately to deeply lobed, lobes somewhat to sharply angular or spatulate, often with 2-3 teeth, sinuses nearly to midrib, secondary veins arched, divergent, (3-)5-7 on each side, apex broadly rounded or ovate; surfaces abaxially light green or somewhat glaucous, tomentose, tomentum persisting or soon falling, adaxially dark green or dull gray, sparsely puberulent to glabrate. Acorns 1-2 on axillary peduncles to 40 mm; cup goblet-shaped, burlike, or spheroid, 15-20 mm deep × 20-30 mm wide, usually completely enclosing nut or merely apex visible, rarely enclosing only 1/2 nut, orifice smaller than nut diameter, often splitting irregularly at maturity, scales closely appressed, especially about margin, laterally connate, broadly triangular, keeled-tuberculate, finely grayish tomentose; nut light brown or grayish, ovoid-ellipsoid or oblong, (15-)25-50 × (10-)20-40 mm, finely puberulent or floccose. Cotyledons distinct. Flowering spring. Bottoms, lowlands, wet forest, streamside forests, swamp forests, periodically inundated areas; 0-200 m; Ala., Ark., Del., Fla., Ga., Ill., Ind., Iowa, Ky., La., Md., Miss., Mo., N.J., N.C., Okla., S.C., Tenn., Tex., Va. The large acorns with hardened cups that enclose all or most of the nut are diagnostic.
Tree to 30 m, with thick, gray bark, the twigs soon glabrescent; lvs narrowly obovate, densely gray-tomentose beneath with horizontally spreading, many-branched stellate hairs, above which project a few erect, few-branched hairs, or with only the latter type of hair; lateral lf- lobes 2-4 pairs, oval, rounded to subacute, rarely emarginate, the lower usually much smaller and separated from the upper by often elongate sinuses; acorns 1.5-2.5 cm, about as thick; cup covering half to all the conic-ovoid nut, the lower scales strongly concave. Wet woods and swamps on the coastal plain; s. N.J. to Fla. and Tex., n. in the interior to s. Ind., s. and w. Ill., and Mo.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.