Trees , to 25 m; trunks often several, crowns round. Bark of mature trunks and branches grayish brown, yellowish, reddish, or creamy white, smooth, irregularly shredding and exfoliating in shaggy sheets when mature; lenticels dark, horizontally expanded. Twigs without wintergreen taste or odor, glabrous to sparsely pubescent, often with scattered, tiny, resinous glands. Leaf blade rhombic-ovate, with 5--12 pairs of lateral veins, 4--8 × 3--6 cm, base broadly cuneate to truncate, margins coarsely doubly serrate to dentate, apex acuminate; surfaces abaxially moderately pubescent to velutinous, especially along major veins and in vein axils, often with scattered, minute, resinous glands. Infructescences erect, conic or nearly globose, 1.5--3 × 1--2.5 cm, shattering with fruits in late spring or early summer; scales often persistent into early winter, lobes 3, ascending, branching distal to middle, narrow, elongate, equal to somewhat unequal in length, apex acute. Samaras with wings narrower than body, usually broadest near summit, not extended beyond body apically. 2 n = 28.
"Tree to 30 m, the brown bark exfoliating in thin layers, scaly- roughened on larger trunks; lvs ovate-oblong or deltoid-ovate, 4–8 cm, acute, sharply double-serrate above, entire toward the cuneate base, tomentose beneath when young, soon glabrescent on the surface but remaining softly villous on the veins beneath and tomentose on the petiole; lateral veins 6–10 pairs; fruiting catkins on peduncles 5–8 mm, cylindric, 1.5–3 cm; scales pubescent, 6–8 mm, parted above the middle into 3 oblong lobes; frs pubescent, depressed-ovate, 3–4 × 4–7 mm, the body 2.5–4 mm wide. Swamps and flood-plain forests; N.H. to Fla., w. to s. O., se. Minn., e. Kans. and Tex."
|River birch, red birch|