Amsonia tabernaemontana #1 (Eastern Blue Star)

Eastern Blue Star is an easy to grow perennial with lime green foliage and true-blue flowers that fade to whitish in the sun. The flowers last for several weeks in May or June and are attractive to Ruby-throated Hummingbirds, as well as many long-tongued insects. The growth habit is clumping but this species does spread readily from seed. In fall it will develop a rich golden color that is an asset in the autumn perennial garden. Eastern Blue Star is adaptable to most soil types and light shade, but prefers moist, loamy soils in full sun. Once established, it can tolerate both drought and brief inundation, making it a good choice for rain gardens.

As a member of the Dogbane family (Apocynaceae), its sap produces a milky latex that deters browsing by deer or rabbits. The Snowberry Clearwing moth hosts on members of this family, though a specific host relationship has not been documented.

Sources:
Growing and Propagating Wild Flowers by Harry R. Phillips
The Midwestern Native Garden by Charlotte Adelman & Bernard L. Schwartz
Herbaceous Perennial Plants by Allan M. Armitage
Growing and Propagating Wildflowers by William Cullina
Missouri Botanical Garden
Lady Bird Johnson Wildflower Center
Illinois Wildflowers