Tree native to the eastern United States with gray, rough bark, a wide crown, and spiny, angular branches. Deciduous leaves are 30 cm long, made up of 9-19 elliptical leaflets, bright green with a bluish underside. It blooms in May-June with hanging clusters of white flowers, 15-25 cm long. The fruits are sessile, linear legumes, 5-10 cm long. It grows in all soils except compact and clayey ones, preferring light and calcareous soils. Often used to stabilize unstable soils thanks to its roots or to enrich poor soils by fixing nitrogen.