Shrub or tree to 10 m. Bark smooth, dark grey. Branchlets grey-brown, glabrous. Buds sessile, with three to six scales. Leaves deciduous, 4–10 × 2.5–8 cm, elliptic to ovate or broadly so, upper surface glabrous, lower surface glabrous except for tufts of hairs in vein axils, 7–13 lateral veins on each side of the midvein, margins densely and finely serrate or biserrate, apex acute, base rounded; petiole 0.5–2 cm long, glabrous or sparsely pubescent. Pistillate inflorescences three to six per raceme, borne on pendulous peduncles, oblong to rounded, 1–2 cm long. Cone woody, bracts 0.3–0.4 cm wide. Flowering May to July, fruiting July to August (China). Li & Skvortsov 1999. Distribution CHINA: Heilongjiang, Jilin, Liaoning, Nei Mongol; NORTH KOREA; RUSSIAN FEDERATION: Manchuria. Habitat Streamsides in temperate forest, between 200 and 1900 m asl. USDA Hardiness Zone 5–6. Conservation status Not evaluated. Illustration Li & Skvortsov 1999.
Alnus mandschurica is not common in cultivation, but with its northerly distribution would seem to have promise for areas with harsh continental climates. It is in cultivation in the United States, from an introduction as seed (CBS-088) collected at 800 m in Changbai Co. of Jilin Province by the North America–China Plant Exploration Consortium 1997 Jilin China Expedition. A group of specimens from this source, planted out in 2000, were faring with mixed fortunes at the Morton Arboretum when seen in June 2006: one was dead, one was struggling, and the third was a vigorous young plant of 1.8 m. This last had big ovate leaves, of a dull matt green, although they had a slightly ‘pewtered’ appearance, with very finely toothed margins.