Yellow Trefoil (Medicago lupulina), or Black Medick, is a short plant with a sprawling habit, bearing clover-like leaves. Its flowers are compact and bright yellow. Its seed pods when ripe are black, smooth and coiled – differing from other Medicks by an absence of spines on the pods and the pods not being buried within the dead flower heads. It flowers from April to July. Habitats include dry grasslands, pastures, road banks and waste places. It is characteristic of relatively disturbed, infertile soils on neutral or calcareous soils. It can tolerate grazing and cutting. It can potentially be lost if vegetation smothers it, so it does require a certain degree of disturbance. Yellow Trefoil seed can remain viable in the soil for several years and can reappear on the reintroduction of management.