阿尔泰山楂 a er tai shan zha

Crataegus purpurea var. altaica Loudon, Arb. Brit. 2: 823. 1838; C. sanguinea Pallas var. incisa Regel; C. sanguinea var. inermis Karelin & Kirilov; C. wattiana Hemsley & Lace var. incisa (Regel) C. K. Schneider.

Trees medium-sized, 3–6 m tall, unarmed, rarely with few 2–4 cm thorns. Branchlets purplish brown or reddish brown when young, grayish brown when old, terete, stout, glabrous; buds purplish brown, suborbicular, glabrous, apex acute. Stipules falcate or cordate, ca. 1 cm, herbaceous, glabrous, margin glandular serrate, apex acute; petiole 2–3.4 cm, glabrous; leaf blade broadly ovate or triangular-ovate, 5–9 × 4–7 cm, veins conspicuous, lateral veins extending to apices of lobes, abaxially barbate in vein axils, adaxially sparsely pubescent, base truncate or broadly cuneate, rarely subcordate, margin irregularly and sharply serrate, usually with 2–4 pairs of lobes, often parted near base, apex acute or obtuse. Compound corymb 3–4 cm in diam., many flowered; peduncle glabrous; bracts caducous, lanceolate, membranous. Pedicel 5–7 mm, glabrous. Flowers 1.2–1.5 cm in diam. Hypanthium campanulate, abaxially glabrous. Sepals triangular-ovate, or triangular-lanceolate, 2–4 mm, both surfaces glabrous, apex caudate-acuminate. Petals white, suborbicular, ca. 5 mm in diam. Stamens 20. Ovary sparsely pubescent apically, 4- or 5-loculed, with 2 ovules per locule; styles 4 or 5. Pome yellow, subglobose, 8–10 mm in diam., glabrous; sepals persistent, reflexed; pyrenes 4 or 5, with concave scars on both inner sides. Fl. May–Jun, fr. Aug–Sep. 2n = 68*.

Slopes, forest understories, stream sides; 400--1900 m. C and N Xinjiang [Russia (SE European part, Siberia)].