小叶桦 xiao ye hua

Betula fruticosa Pallas var. cuneifolia Regel.

Trees to 6 m tall; bark grayish white, exfoliating in flakes. Branches grayish or grayish brown, resinous glandular; branchlets yellow-brown, densely pubescent and resinous glandular. Petiole slender, ca. 1 cm, densely pubescent; leaf blade rhombic or rhombic-obovate, 1.5-5 × 1-3.5 cm, both surfaces sparsely pubescent and resinous punctate when young, base cuneate, rarely broadly cuneate, margin irregularly and doubly or simply roughly serrate, apex acute or obtuse; lateral veins 4-6 on each side of midvein. Female inflorescence oblong-cylindric, 1-2.5 cm × 7-8 mm; peduncle erect, 5-10 mm; bracts 5-6 mm, sparsely pubescent and ciliate, 3-lobed, middle lobe oblong, lateral lobes erect or slightly spreading, ovate or oblong, ca. 1/2 as long as middle lobe. Nutlet ovate, ca. 2.5 × 1.5 mm, densely pubescent, with membranous wings ca. as wide as nutlet. Fl. Jun-Jul, fr. Jul-Aug.

Temperate broad-leaved forests; 1200-1600 m. Xinjiang (Altay Shan, Hami Xian) [Kazakhstan, Mongolia]