Medicago polymorpha

Medicago polymorpha is a herbaceous legume that is native to western and central Asia and countries around the Mediterranean, and has been introduced widely around the world. It is found in particular in regions with a Mediterranean climate, but is by no means confined to them. Introduction has been a result of accidental transport of the spiny seed pods and probably also of deliberate introduction as a fodder plant;the relative importance of these two means of spread cannot be determined. The species can be a useful pasture plant, in particular because of its nitrogen-fixing ability, but in other places it is considered to be an invasive weed;it can sometimes be toxic to livestock, and the seed pods can be a serious contaminant of wool.