Betula delavayi Franch.

Shrubs or trees to 8 m tall; bark dark gray. Branches diagonal or prostrate, sometimes erect; branchlets brown, densely yellow villous. Petiole 5-10 mm, sparsely villous; leaf blade elliptic, oblong, ovate, or broadly ovate, (1.5-)2-7 × 1-4 cm, abaxially sparsely resinous punctate and white sericeous-villous along veins, adaxially densely yellow sericeous-villous when young, base rounded, margin doubly minutely serrate, apex acuminate or subrounded; lateral veins (5-)9-21 on each side of midvein. Female inflorescence oblong or oblong-cylindric, 1-2.5 cm × 5-10 mm; peduncle ca. 5 mm, villous; bracts 5-10 mm, pubescent, ciliate, sometimes densely villous, 3-lobed, middle lobe lanceolate or oblong, lateral lobes spreading, ovate, ca. 1/2 as long as middle lobe. Nutlet obovate or elliptic, 2.5-3 × 1.5-2 mm, pubescent, with very narrow wings. Fl. Jun, fr. Jul-Aug.

?Gansu, W Hubei, ?Qinghai, W Sichuan, E Xizang, NW Yunnan.

* Broad-leaved forests, thickets; 2400-4000 m.