Japan Flora: Tree with gray-brown, glabrescent to loosely brown-pubescent branches; leaves oblong-ovate, acuminate, acute to cuneate at base, glabrous except for axillary tufts of red-brown hairs beneath or slightly pubescent on both sides, pale green beneath, with 7-9 pairs of rather slender arcuate lateral nerves, the short marginal teeth mucro­nate, the petioles 1-3.5 cm. long; staminate inflorescence con­sisting of 2 to 5 aments borne on the upper part of the branches, the pistillate consisting of 1-5 aments borne just below, the fruiting aments ovoid-ellipsoid, 15-20 mm. long. Mar.  Wet lowlands

Hokkaido, Honshu, Shikoku, Kyu­shu; common and frequently planted around paddy fields; variable. Korea, Ussuri, and Manchuria.

Korea Flora: Tree up to 20m. Winter Buds and Stems: Elongated ovoid, 3 bud scales; terminal buds similar to lateral buds (3-8mm long), stalked. Leaf scars semicircular. Young branches densely to sparsely pubescent. Leaves: Oblong, lanceolate-ovate or broadly lanceolate, apex acuminate, base cuneate or rounded, 6-12cm × 4.5-5cm, finely serrate, glabrous or with fine hairs, 7-8 pairs of veins. Petiole 2-4cm long. Flowers: Male catkins 4-9cm long, with 3-4 flowers per bract, each with 4 petals and 4 stamens. Female catkins elongate-ovoid with 2 female flowers per bract. Fruit and Seeds: Nuts in groups of 2-6, 15-25mm long, elongate-ovoid. Nutlets flat, broadly elliptic or spathulate, 3-4mm long, wings indistinct.

Sporophyte Chromosome Number: 56
Flowering Period: Early March to late April
Fruiting Period: October
Distribution: Northeastern China, Far Eastern Russia, Japan; throughout Korean Peninsula, but mainly found as scattered individuals in low-elevation areas of Gyeonggi-do and Gangwon-do

Ecological Characteristics: Light-demanding, especially in youth. Grows well in moist, fertile soils. Well-adapted to valleys, riverbanks, and lakeshores, making it suitable for wetland afforestation, though rarely used for this purpose. In the Korean Peninsula, mostly found as isolated individuals on islands or coastal areas, rarely forming pure stands except in wetlands.