Robinia pseudoacacia - Black locust

Black Locust
Robinia pseudoacacia

This member of the legume family is a native to the Appalachian and Ozark mountains, but has escaped cultivation and reproduces on its own in both the eastern and western U.S. The roots of this species (as well as other legume species) produce root nodules containing the nitrogen fixing bacteria, Rhizobium. This partnership changes atmospheric nitrogen into a form that is usable by plants.