Medicago rigidula
Medicago rigidula
Kara yonca
Small annual herb, 10-25 cm, with simple or glandular hairs. Stipules dentate, with 3-6 short teeth. Leaflets 4-6 x 3-6 mm, cuneate to broadly obovate, truncate to obtuse. Peduncle 1-2-flowered, usually longer than petiole. Flowers 6-8 mm. Calyx teeth about equal to tube. Corolla less than 2 x as long as calyx. Young fruit contracted within calyx. Fruit discoid, cylindrical, ovoid or spherical, 5-12 mm high, hardening at maturity, spiny, tubercular or spineless, covered with simple or glandular hairs, sometimes glabrescent, exceptionally glabrous; coils 4-7, adpressed or not, broadest 5-10 mm diam.; on surface of coils 12-17 strongly bent radial veins, anastomosing near submarginal vein; tubercles or spines 8-18 from each surface of coil, with or without a groove; angle of insertion 90-180°. Fl. 4-7. Fallow fields, roadsides, steppe, oak andpine woods, s.l.-1800 m.
A complex species including greatly differing forms connected by intermediates. The Turkish material is especially variable. Further studies on this species will have to be carried out.
1. Fruits spherical to ellipsoid, usually densely covered with short, simple hairs; dorsal suture broad, not protruding beyond submarginal veins; coils adpressed
2. Fruit with more or less long, slender spines; coils 5-6 mm diam. var. cinerascens
2. Fruit smooth or bearing more or less long tubercles; coils 6-9 mm diam. var. submitis
1. Fruits discoid to cylindrical; dorsal suture at least slightly protruding beyond the submarginal veins; coils not adpressed
3. Pod densely hairy or villose, rarely glabrescent; coils thin ; dorsal suture protruding beyond submarginal vein; coils not exceeding 8 mm diam.; angle of insertion of spines about 1800 var. rigidula
3. Pod glabrescent or glabrous; coils thick; dorsal suture 1,5-2 mm thick, very slightly protruding beyond submarginal vein; coils more than 8 mm diam.; angle of insertion of spines about 900 var. agrestis
Distribution of species: S. Europe, N.W. Africa, S.W. Asia eastwards to Afghanistan.
