13. Medicago arabica (Linnaeus) Hudson, Fl. Angl. 288. 1762.
褐斑苜蓿 he ban mu xu
Medicago polymorpha Linnaeus var. arabica Linnaeus, Sp. Pl. 2: 780. 1753; M. maculata Willdenow; M. oxalioides Schur.
Annual herbs, 40-65 cm. Stems decumbent or spreading, longitudinally ridged, sparsely hairy, hairs simple and multicellular-glandular. Stipules ovate-lanceolate, 5-12 mm, incised, with 6-8 deep lobes; petioles slender, 2-8(-12) cm, 2-5 × as long as peduncle; leaflets usually with a dark colored patch at center, obcordate to broadly obovate, 7-25(-30) × 14-32 mm, sparsely hairy abaxially, glabrous adaxially, base broadly cuneate, margin subentire or shallowly serrate, apex rounded or emarginate. Flowers (1 or)2-5(or 6) in axillary racemes; peduncles with a terminal cusp; bracts ca. 1 mm; pedicels longer than or equal to bracts. Corolla yellow, 5-6.5 mm; standard broadly obovate, retuse. Legume cylindric to globose, 5-7 mm, tightly coiled in 3-7 spirals, turning counterclockwise, 5-8 radial veins on coil face, spines 13-15 in each row. Seed yellowish brown, oblong-elliptic, 2.5-3.5 × 1.2-1.5 mm, smooth. Fl. Mar-May, fr. May-Aug.
Cultivated, rather moist stream banks, grasslands. Fujian, Guangdong, Guangxi, Hainan, Hunan, Jiangsu [native to the Mediterranean region].