Black medick belongs to the member of pea family or Fabaceae. It is a low trailing annual, biennial or short lived perennial which reaches 1 to 2 feet length. Stems are prostate, slender, four angled, branched at base and glabrous to hairy. Leaves are pinnately trifoliate. Leaflets are rounded, ovate, finely pubescent and ½ inch long. Flowers are small, bright yellow and rounded to slightly elongated and borne in dense clusters which measures ½ to ¾ inch long. Inflorescence is a rounded to slightly elongated cluster of 10 to 50 tiny flowers. Seeds are kidney shaped, gold or brown and 1/16 inches long.
It is native to Europe, near east, north Africa and most of Asia including China, India and Korea. It is naturalized in central Asia, South Africa, Japan, New Zealand, Australia, Canada, the United States and South America. It is found throughout United States including Alaska and Hawaii. It thrives well in dry to moist and well drained soils.
Corolla is yellow, zygomorphic and 2–3 mm (0.08–0.12 in.) long and fused at base. Calyx is five lobed. Inflorescence is an axillary, globose-elongated, long stalked and dense raceme.
Leaves
Leaves are stalked, stipulate and alternate. Leaflets are obovate having notched tips and sharp pointed or tip with toothed margins.
Fruit
Fruits are kidney shaped, glabrous, net veined, coiled and 1.5-3 mm (0.06-0.12 in.) long. It is a one seeded, brownish black and indehiscent pod.
Habitat
Medicago lupulina is found in roadsides, lawns, waste ground, harbours, railway yards and shores.
