False indigo is a deciduous shrub that typically grows to 4-12′ (less frequently to 20′) tall with a spread often in excess of its height. It is native to moist open woodland areas, floodplains, stream banks and swamp margins. It features compound, odd-pinnate leaves (each to 12″ long). Each leaf contains 11 to 35 spiny-tipped, oval to elliptic, dull gray-green leaflets (to 2″ long) with glandular dots and toothless margins. Tubular scented flowers (each to 3/8″ long) bloom in May-June in dense, spike-shaped clusters (racemes) to 8″ long.
Plants contain indigo pigment, but in quantities too small for commercial use (hence the common name of false indigo).