Large tree with long, straight trunk and massive branches forming a rounded top.
Leaves alternate, simple, 3–7 inches long, broadly triangular, abruptly pointed, with coarse teeth with tiny hairs, small glands at base of leaf blade; upper surface green, shiny; lower surface paler, smooth; leaf stalk slender, flattened.
Bark thin, smooth, yellow-green when young; thick, corky, brown to gray, with deep, straight grooves and wide, flat ridges with age.
Twigs stout, angular, yellowish to brown, smooth; pores prominent; bud at tip about ½ inch long, brown, with sticky bud scales.
Flowers March–May, male and female flowers in catkins on separate trees before leaves emerge; petals absent.
Fruits May–June, drooping catkins 5–10 inches long; capsules widest at base, about ¼ inch long, splitting into 2–4 parts; seeds brown, small, numerous, each with tuft of long cottony hairs.
Similar species: Lombardy poplar (Populus nigra 'Italica').