Trees to 30 m tall; bark dull gray, furrowed when older; crown broadly ovoid. Branchlets yellowish, terete, glabrous. Buds russet, ovoid, very viscid. Petiole ca. as long as or longer than leaf blade, laterally flattened, glabrous; leaf blade rhombic, rhombic-ovoid, or deltoid, 5-10 × 4-8 cm, thinly leathery, abaxially greenish, adaxially green, base cuneate or broadly cuneate, rarely truncate, margin crenate-serrate, ciliate, apex long acuminate. Flower buds outwardly curved at apex. Male catkin 5-6 cm; rachis glabrous; bracts brownish, 3-4 mm, membranous, laciniate. Male flower: stamens 15-30; anthers purplish red. Fruiting catkin 5-10 cm. Female flower: ovary ovoid, glabrous, stipitate; stigmas 2. Capsule ovoid, 5-7 × 3-4 mm, 2-valved, stipitate. Fl. Apr-May, fr. Jun. 2n = ?19*, 38*, 57.
"Tall tree with dull gray branches and dark, furrowed bark on older trunks; petioles distinctly flattened; winter buds resinous; lvs pubescent when young, finely toothed, the teeth to ca 1 mm deep, more spreading than in no. 9 [Populus deltoides Marshall], only slightly or not at all incurved; lvs of short shoots rhomboid-ovate, with cuneate base, of long shoots broadly deltoid-ovate, truncate at base, abruptly pointed; floral disk 1–2 mm wide, stamens 20–30; stigmas 2, broadly dilated; frs ovoid, 7–9 mm, twice as long as the pedicels, with 4–8 seeds per placenta; 2n=38. Native of Eurasia, frequently planted, and occasionally escaped. The Lombardy poplar is a common horticultural form with erect branches, forming a long, columnar crown. (P. italica; P. nigra var. italica; P. dilatata)"