A new cultivar of interspecific Baptisia, `Midnight`, characterized by its upright, vase-shaped growth habit with long inflorescences of violet-blue flowers held well above the foliage, its secondary inflorescences that are produced after the primary inflorescences have past peak producing a long blooming period of at least 3 weeks, its lack of foliage on the lower 20 to 40 cm of stem for suitability for planting with other plants, and its adaptability to cultivation in alkaline clay soils.