This is Baptisia australis, also known as False Indigo, Redneck Lupine, and Blue Wild Indigo. This perennial plant can get about 4 feet tall at the most. It likes to live in the full sun and will bloom from late Spring into the middle of the Summer. This is the larval host plant for the Orange Sulphur, the Clouded Sulphur, and the Eastern Tailed Blue butterflies. The Eastern Tailed Blue butterflies lay their eggs on the flower buds of the Baptisia australis and the caterpillars eat the flowers, bud, and seeds. It is also a nectar source for countless butterflies, bees and other insects. The Frosted Elfin butterfly Caterpillars eat the flowers and young seedpods of False Indigo; This is a rare and uncommon butterfly that you can lure into your garden with Baptisia australis. Another rare butterfly that can be coaxed into your garden is the Hoary Edge Skipper; Their eggs are laid in the flower buds and then the caterpillars eat the flowers and seedpods. The Wild Indigo Duskywing is also attracted to this plant. USDA Hardiness Zones 3 to 10.