12. Crataegus dahurica Koehne ex C. K. Schneider, Ill. Handb. Laubholzk. 1: 773. 1906.
光叶山楂 guang ye shan zha
Shrubs or small trees, deciduous, 2–6 m tall; thorns 1–2.5 cm, slender, sometimes absent. Branchlets purplish brown when young, dark brown when old, wilted, glabrous, with sparse, oblong lenticels; buds purple, suborbicular or triangular, glabrous. Stipules lanceolate or ovate-lanceolate, 6–8 mm, herbaceous, glabrous, margin serrate, apex acuminate; petiole 7–10 mm, glabrous; leaf blade rhombic-ovate, rarely elliptic-ovate to obovate, 3–5 × 2.5–4 cm, both surfaces glabrous, base cuneate or broadly cuneate, margin sharply doubly serrate, entire near base, with (2 or)3–5 pairs of lobes at apical 2/3 of margin; lobes ovate, apex acuminate. Compound corymb 3–5 cm in diam., many flowered; peduncle glabrous; bracts caducous, linear-lanceolate, membranous. Pedicel 8–10 mm, glabrous. Flowers ca. 1 cm in diam. Hypanthium campanulate, abaxially glabrous. Sepals linear-lanceolate, ca. 3 mm, margin entire or with 1 or 2 pairs of teeth, both surfaces glabrous. Petals white, suborbicular or obovate, 4–5 × 3–4 mm. Stamens 20. Styles 2–4, glabrous. Pome orangish red or orangish yellow, subglobose or oblong, 6–8 mm in diam., glabrous; sepals persistent, reflexed; pyrenes 2–4, with concave scars on both inner sides. Fl. May, fr. Aug. 2n = 34*.
Grassy places on river banks in forests, sandy slopes, thickets; 500--1500 m. N Hebei, Heilongjiang, Nei Mongol [N Mongolia, Russia (E Siberia)].
