Description from Flora of China
Trees to 25 m tall. Branches yellowish gray; branchlets yellowish brown, slender, subglabrous, pilose when young. Buds viscid. Petiole terete, 1.5-3 cm; leaf blade ovate, 6-10 × 2.5-7 cm, abaxially greenish, glabrous, adaxially dull green, pilose along veins, base rounded, margin crenate-serrulate, ciliate, apex acuminate. Fruiting catkin to 15 cm; rachis glabrous. Capsule ovoid, densely downy, 2(or 3)-valved; stipe to 5 mm.
Very similar to Populus szechuanica var. tibetica but branchlets yellowish brown, subglabrous, downy only when young; petiole shorter; leaf blade smaller, base rounded, margin ciliate; catkin rachis glabrous; capsule 2-valved, densely downy; stipe to 5 mm.
* Along rivers; 1700-3800 m. Xizang