金平桦 jin ping hua

Trees. Branches dark gray; branchlets grayish, glabrous. Petiole robust, ca. 1.5 cm; leaf blade oblong-lanceolate, 7-10 × 3.5-5 cm, papery, abaxially sparsely resinous punctate, villous along veins, adaxially glabrous, base rounded, margin irregularly and doubly minutely serrate, apex acuminate; lateral veins ca.13 on each side of midvein. Female inflorescence 1, or 2 or 3 in a cluster, oblong or oblong-cylindric, 4-5 × 1-1.2 cm; peduncle 6-7 mm or ± obscure; bracts 6-7 mm, with a tuft of coarse hairs at base, ciliate, 3-lobed, middle lobe ovate-lanceolate, lateral lobes spreading, ovate, ca. 1/3 as long as middle lobe. Nutlet elliptic, ca. 2 mm, with membranous wings ca. 1/2 as wide as nutlet. Fl. Apr-May, fr. Jun-Aug.

* Subtropical forests; circa 2200 m. SE Yunnan (Jinping Xian)

A. K. Skvortsov indicates that this species is similar to Betula utilis, and further studies may show that they are conspecific.