Originally native only in southeastern Indiana near the Ohio River; Now occurs throughout the state. This unusual tree generally has thorns on smaller branches and, like other members of the clover family, has nodules on the roots that contain nitrogen-fixing bacteria that take nitrogen from the air and convert it into a fertilizer-type form that can be used by the plant. Since it can grow well in poor soil, this tree is often planted for erosion control. Leaves are compoundwith oval leaflets. The tree produces large white pea-like flowers in the early spring that have an intoxicatingly sweet smell.