*Medicago lupulina
Fruit reniform, c. 2 mm long, with concentric veins on the convex faces, 1-seeded, black when ripe. Flowers very small, numerous, in ovoid heads; peduncles slender, longer than the subtending leaf. Corolla yellow. Pubescent, procumbent annual or biennial. Widespread. Introd. from Europe and temp. Asia. Black Medic