Ribbed Melilot is a tall plant of waste ground and roadsides. The dried plant smells of hay, so was used to make poultices.
It is very similar to Tall Melilot (Melilotus altissimus): the differences being that the Ribbed Melilot has keel petals shorter than the other petals (Tall Melilot has all its petals of the same length), and its seeds are hairless and wrinkled with transverse ridges and are brown when ripe.

Seeds with transverse ridges		Trifoliate leaflets