33. Rhamnus cathartica Linnaeus, Sp. Pl. 1: 193. 1753.
药鼠李 yao shu li
Shrubs or trees, dioecious, 5-8 m tall, spinose. Young branches glabrous; branchlets opposite or subopposite, purple-red or silvery-gray, terminating in a spine; terminal buds elliptic, with few scales, margin ciliate. Leaves subopposite or alternate, or fascicled on short shoots; petiole 1-2.7 cm, adaxially canaliculate, sparsely hairy or subglabrous; leaf blade elliptic, ovate-elliptic, or ovate, 3-6.5 × 1.5-3 cm, papery, both surfaces glabrous, lateral veins 3 or 4 pairs, proximal pair often slightly stronger than others, base rounded or broadly cuneate, margin densely crenate-serrate, apex shortly acuminate, acute, or rounded-obtuse. Flowers unisexual, 4-merous, usually 10-fascicled on short shoots or in leaf axils of lower part on long shoots. Pedicels 2-4 mm. Male flowers with petals; ovary rudimentary. Female flowers apetalous, with minute rudimentary stamens; ovary 3-loculed; style long, 3-fid. Drupe black, globose, to 1 cm in diam., with 3 stones, with persistent calyx tube at base. Seeds yellow, abaxially with margined furrow extending over 3/4 of length. Fl. May-Jun, fr. Jul-Sep. 2n = 24.
Thickets, valleys, slopes; 1200-1400 m. N Xinjiang [Russia (W Siberia); NW Africa, C and SW Asia, Europe].
The fruit is used medicinally for treating constipation.