19. Betula costata Trautvetter, Mém. Acad. Imp. Sci. St.-Pétersbourg Divers Savans. 9: 253. 1859.
硕桦 shuo hua
Betula ermanii Chamisso var. costata (Trautvetter) Regel; B. ulmifolia Siebold & Zuccarini var. costata (Trautvetter) Regel.
Trees to 30 m tall; bark grayish brown, exfoliating in papery flakes. Branches red-brown, glabrous; branchlets brown, densely yellow resinous glandular, sparsely pubescent. Petiole 0.8-2 cm; leaf blade ovate or ovate-elliptic, 3.5-7 × 1.5-4.5 cm, abaxially densely resinous punctate, villous, bearded in axils of lateral veins, adaxially glabrous, base rounded or subcordate, margin irregularly and doubly minutely serrate, apex acuminate or caudate-acuminate; lateral veins 9-16 on each side of midvein. Female inflorescence 1, oblong, 1.5-2.5 × ca. 1 cm; peduncle 2-5 mm; bracts 5-8 mm, ciliate, 3-lobed, middle lobe oblong-lanceolate, lateral lobes spreading, oblong, ca. 1/3 as long as middle lobe. Nutlet obovate, ca. 2.5 mm, glabrous, with membranous wings ca. 1/2 as wide as nutlet. Fl. May-Jun, fr. Jul-Sep.
Mixed forests of coniferous and broad-leaved trees; 600-2500 m. Hebei, Heilongjiang, Jilin, Liaoning, Nei Mongol [Korea, E Russia (Primorye)]
The wood is straight grained, coarse textured, and cracks easily; it is used for making carrying poles and for fuel and charcoal.