Plants to 55 m, 35 dm diam.; moderately to strongly heterophyllous, (often 2 or more trunks near base). Bark light brown, deeply furrowed. Branchlets yellow-brown, becoming tan by third year, round or 5-angled, coarse or not, (1–)2–3.5(–6) mm diam., glabrous or thinly long-hairy. Winter buds greenish yellow, glabrous or stiffly hairy, resinous (resin yellow, moderately fragrant); terminal buds (6–)8–15(–21) mm; flowering buds separated on branchlets, (8–)14–20(–28) mm. Leaves: petiole distally flattened at right angle to plane of blade, (1–)3–8(–13) cm, about equaling blade length, (glabrous); blade broadly triangular-ovate, (1–)3–9(–14) × (1.5–)3–9(–16.5) cm, w/l = 4/5–6/5, base truncate to cordate or broadly cuneate, basilaminar glands 0–6, round or tubular, margins translucent, ciliate, apex abruptly short- or long-acuminate, surfaces grayish green to bright green, glabrous (or visibly pilose only at emergence); preformed blade margins coarsely crenate-serrate midblade, teeth (3–)5–15(–30) on each side (graded, rounded), sinuses (0.4–)0.7–5(–7) mm deep; neoformed blade margins crenate-serrate, teeth (10–)25–40(–55) on each side (graded), sinuses (0.1–)0.5–1.5(–3) mm deep. Catkins loosely (3–)15–40(–55)-flowered, (0.7–)5–18(–24 in fruit) cm; floral bract apex deeply cut, not ciliate. Pedicels 1–13(–17 in fruit) mm. Flowers: discs saucer-shaped, not obviously oblique, entire, 1–3(–4) mm diam.; stamens 30–40(–55); anthers truncate; ovary (3- or)4-carpelled, ovoid; stigmas 2–4, platelike, spreading. Capsules ovoid, (4–)8–11(–16) mm, glabrous, (3- or)4-valved. Seeds (3–)7–10(–23) per placenta. 2n = 38.