Securigera varia (synonym Coronilla varia), commonly known as crown vetch or purple crown vetch. Crownvetch is a tough, aggressive spreading plant that will crowd out its neighbours in a show garden but is well suited to a sunny bank, where it will grow for decades with little to no fertilizing, mowing, or weeding since the thick foliage prevents weeds from growing amongst it. It is also a common host-plant for the moth Zygaena ephialtes. Often used for soil rehabilitation on the roadside in america. Crown vetch is toxic to horses it can cause slow growth, paralysis, or even death. However, this is not true for ruminant animals such as cattle, goats, and sheep.