Ononis is a large genus of perennial herbs and shrubs from the legume family Fabaceae. The members of this genus are often called restharrows as some species are arable weeds whose tough stems would stop the harrow. They are natively distributed in Europe. In herbalism restharrow is used to treat bladder and kidney problems and water retention.
Ononis natrix, Perennial subshrubs, 10-70 cm tall, densely glandular hairy. Stem erect, much branched, unarmed. Leaves 3-foliolate, lower rarely 5-foliolate, upper rarely 1-foliolate; leaflets oblong, obovate, to broadly linear, 1-3 cm, base cuneate, apex acute.

Flowers in lax, leafy racemes or panicles, solitary at nodes, or at tips of lateral branchlets; pedicel 5-20 mm; bract aristate. Calyx 8-12 mm; teeth linear-lanceolate, 2.5-4 * length of tube. Corolla yellow, with veins scarlet or purple, 12-20 mm. Leg­ume linear-elliptic, 10-25 × 3-4 mm, 2-3 * as long as persis­tent calyx, beaked. Seeds 6-9, globose, minutely tuberculate. Fl. May-Oct.