黑桦树 hei hua shu

Shrubs much branched, dioecious, to 2.5 m tall, spinose. Branches opposite or subopposite, terminating in a spine, puberulent or glabrous, shiny or slightly scabrous. Leaves opposite or subopposite on long shoots, fascicled at ends of short shoots; stipules narrowly lanceolate, ca. 4 mm; petiole 5-20 mm, glabrous or subglabrous; leaf blade abaxially pale green, adaxially green, elliptic, ovate-elliptic, or broadly ovate, rarely spatulate, 1-3.5 × 0.6-1.2 cm, leathery, both surfaces glabrous, lateral veins 2 or 3 pairs, prominent abaxially, slightly impressed adaxially, base cuneate or subrounded, margin entire or inconspicuously serrulate, apex rounded-obtuse, rarely emarginate. Flowers unisexual, 4-merous, usually few- to 10-clustered at ends of short shoots. Pedicels 4-5 mm. Drupe red, turning black at maturity, obovoid-globose or subglobose, ca. 4 mm, 4-6 mm in diam., with persistent calyx tube at base, mostly with 2(or 3) stones; fruiting pedicel 4-6 mm, glabrous. Seeds brownish, obcordate, abaxially with a dark margined, broad furrow extending over 1/2-3/5 of length. Fl. May-Jun, fr. Jun-Sep.

Thickets on mountain slopes; 900-2700 m. Gansu, N Hebei, Nei Mongol, Ningxia, Shaanxi, Shanxi, NW Sichuan [Mongolia].