46. Quercus bicolor Willdenow in G. H. E. Muhlenberg, Ges. Naturf. Freunde Berlin Neue Schriften. 3: 396. 1801.
Swamp white oak, chêne bicolore
Quercus bicolor var. angustifolia Dippel; Q. bicolor var. cuneiformis Dippel; Q. bicolor var. platanoides A. de Candolle; Q. platanoides (Lamarck) Sudworth
Trees , deciduous, to 30 m. Bark dark gray, scaly or flat-ridged. Twigs light brown or tan, 2-3(-4) mm diam., glabrous. Buds light or dark brown, globose to ovoid, 2-3 mm, glabrous. Leaves: petiole (4-)10-25(-30) mm. Leaf blade obovate to narrowly elliptic or narrowly obovate, (79-)120-180(-215) × (40-)70-110(-160) mm, base narrowly cuneate to acute, margins regularly toothed, or entire with teeth in distal 1/2 only, or moderately to deeply lobed, or sometimes lobed proximally and toothed distally, secondary veins arched, divergent, (3-)5-7 on each side, apex broadly rounded or ovate; surfaces abaxially light green or whitish, with minute, flat, appressed-stellate hairs and erect, 1-4-rayed hairs, velvety to touch, adaxially dark green, glossy, glabrous. Acorns 1-3(-5) mm, on thin axillary peduncle (20-)40-70 mm; cup hemispheric or turbinate, 10-15 mm deep × 15-25 mm wide, enclosing 1/2-3/4 nut, scales closely appressed, finely grayish tomentose, those near rim of cup often with short, stout, irregularly recurved and sometimes branched, spinose awns emerging from tubercle; nut light brown, ovoid-ellipsoid or oblong, (12-)15-21(-25) × 9-18 mm, glabrous. Cotyledons distinct. 2 n = 24.
Flowering in spring. Low swamp forests, moist slopes, poorly drained uplands; 0-1000 m; Ont., Que.; Ala., Conn., Del., Ill., Ind., Iowa, Ky., Maine, Md., Mass., Mich., Minn., Mo., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., Tenn., Vt., Va., W.Va., Wis.
Putative hybrids between Quercus bicolor and Q . macrocarpa are common in areas of contact. The hybrids tend to have more deeply lobed leaves and varying degrees of development of awns as a fringe along the margin of the acorn cup. Such characteristics occur sporadically throughout many populations of Q . bicolor ; in some cases they may occur because of subtle introgression.
The Iroquois used Quercus bicolor in the treatment of cholera, broken bones, consumption, and as a witchcraft medicine (D. E. Moerman 1986).