4. Ziziphus montana W. W. Smith, Notes Roy. Bot. Gard. Edinburgh. 10: 78. 1917.
山枣 shan zao
Trees or shrubs, to 14 m tall, spinose. Young and annual branches red-brown tomentose; branchlets brown or purple black, with conspicuous lenticels. Stipular spines 2, both erect, red-purple, 1-1.8 cm; petiole 7-15 mm, ± pilose at first, glabrescent; leaf blade abaxially pale green, adaxially green, elliptic, ovate-elliptic, or ovate, 5-8 × 3-4.5 cm, papery, abaxially ferruginous pubescent on major veins, adaxially glabrous, 3(or 5)-veined from base, veins prominent on both surfaces, midvein without conspicuous secondary veins, base asymmetric, subrounded, margin crenulate, apex obtuse or subrounded, rarely shortly acute. Flowers greenish, few to 10 crowded in axillary dichotomous cymes; peduncles 1-2 mm, densely pilose. Sepals triangular, ca. 2 mm, abaxially brownish pilose, apex acute. Petals obovate, subequal to sepals, clawed. Disk thick, fleshy, 5-lobed. Ovary globose, deeply immersed in disk; styles long, 2-branched. Drupe yellow-brown, globose or subglobose, 2.5-3 cm, 2-2.5 cm in diam., glabrous, concave at base; fruiting pedicel often curved, 6-12 mm, sparsely pilose; mesocarp 6-7 mm, thick, spongy; endocarp woody, wall 3-4 mm, 2-loculed, with 2 seeds. Seeds compressed, obovoid, 9-10 mm. Fl. Apr-Jun, fr. May-Aug.
● Sparse forests in valleys, dry stony places; 1400-2600 m. SW and W Sichuan, E Xizang, NW Yunnan.
This species differs from Ziziphus mairei in having tomentose annual branches, leaf blade elliptic or ovate-elliptic, with an obtuse or subrounded apex, and mesocarp spongy and thicker than endocarp, not thickening at basal margin.