Amorpha canescens (Leadplant)

From CONPS:

Leadplant is a small, deciduous shrub, 1-3 ft. tall, with tiny, purple flowers grouped together in colorful, terminal spikes. Pinnately compound leaves are covered with short, dense hairs, giving the plant a grayish appearance. This is one of the most conspicuous and characteristic shrubs of the upland prairies. It has very deep roots, 4 feet or deeper. It is not disrupted by grazing animals, and provides nectar for pollinators. Grows in drainage that dries up later in the season.