Shrub Indiana Native Robinia hispida var. fertilis [Bristly Locust] Can fix nitrogen. Especially well adapted to poor, dry, alkaline soils. Though native, can be invasive on sandy soils. Frequent pruning may be needed.
Tree Indiana Native Robinia pseudoacacia [Black Locust] Widely variable in form, the most picturesque are straight-trunked with branches abruptly fanning out at the top. Fixes N2. Locust borers are troublesome and difficult to control, but many trees live with them successfully for many years. Leaf minors and permanently wet soils can be problems.