Wild indigo, also commonly called blue false indigo, fulfills all these criteria.
From the charlotteobserver.com
Low-maintenance blue false indigo grows 3 to 4 feet tall and wide in full sun to partial shade.
From the stltoday.com
Blue false indigo puts down deep roots and is drought resistant.
From the dailyherald.com
Blue false indigo or baptisia australis blooms in May and June with striking indigo blue, pea-like flowers.
From the dailyherald.com
Other plants that might work are baptisia australis or blue false indigo and white wild indigo, which is baptisia leucantha.
From the dailyherald.com
The name blue false indigo came about because early Americans used the plant as dye, though an inferior one to the true indigo plant of the West Indies, the association says.