Ononis spinosa, L.

32. O. spinosa L. View in CoL , Sp. Pl. 716 (1753).

Dwarf shrub 10-80 cm; stems variously hairy and sparsely glandular, usually erect or ascending, usually spiny. Leaves mostly 3-foliolate; leaflets very varied in shape. Bracts usually 1 -foliolate. Flowers borne singly, rarely in pairs, at each node, in lax racemes. Calyx glandular- pubescent, and shortly hirsute at the mouth. Corolla 6-20 mm, pink or purple, usually much exceeding the calyx. Legume 6-10 mm. Seeds 1 or few, c. 2 mm, brown or blackish, tuberculate, rarely smooth. 2/i = 30. W., C. & S. Europe, extending to S. Norway and N. W. Ukraine. All except Az Fa Fe Hb Is Rs (N, B, E) Sb.

One pair of chromosomes possesses a long constriction so that it frequently appears to be two pairs; this probably accounts for the records of 2n = 32 for this species and for records of 2n = 32 and 64 for 33.

1 Plant with weak spines; legume shorter than calyx; corolla 15-20 mm (d) subsp. austriaca 1 Plant with robust spines; legume equalling or exceeding calyx 2 Corolla 10-20 mm; legume 2- to 4-seeded (a) subsp. spinosa 2 Corolla 6-10 mm, little longer than calyx; legume 1 -seeded 3 Seeds tuberculate; leaflets 6-10 mm (b) subsp. antiquorum 3 Seeds smooth; leaflets 10-20 mm (c) subsp. leiosperma