26. Betula dahurica Pallas, Reise Russ. Reich. 3: 224. 1776.
黑桦 hei hua
Betula dahurica var. oblongifolia Liou; B. dahurica var. ovalifolia Liou; B. dahurica var. tiliifolia Liou; B. maackii Ruprecht; B. maximowiczii Ruprecht.
Trees to 20 m tall; bark black-brown, fissured. Branches red-brown or dark brown, shiny, glabrous; branchlets red-brown, villous, with dense, resinous glands. Petiole 0.5-1.5 cm; leaf blade ovate, broadly ovate, rhombic-ovate, or elliptic, 4-8 × 3.5-5 cm, abaxially densely resinous glandular along veins, bearded in axils of lateral veins, adaxially glabrous, base subrounded, broadly cuneate, or cuneate, margin irregularly and acutely doubly serrate, apex acute or acuminate; lateral veins 6-8 on each side of midvein. Female inflorescence erect or pendulous, oblong-cylindric, 2-2.5 × ca. 1 cm; peduncle 5-12 mm; bracts 5-6 mm, ciliate, 3-lobed, middle lobe oblong-lanceolate, lateral lobes spreading or recurved, ovate or broadly ovate, ca. as long as middle lobe. Nutlet broadly elliptic, glabrous, with membranous wings ca. 1/2 as wide as nutlet. Fl. Jun-Jul, fr. Jul-Aug. 2n = 56.
Mixed or coniferous forests, dry or moist, sunny slopes, rocks on mountain summits; 400-1300 m. Hebei, Heilongjiang, E Jilin, N Liaoning, Nei Mongol, Shaanxi, Shanxi [Japan, Korea, E Mongolia, Russia (Far East)]
The wood is hard and dense, and is used in house construction and for making agricultural tools and furniture.