Amsonia hubrichtii (common name: Threadleaf Blue Star)
Blue star is a showy, three-season perennial that is finally starting to get the attention I think it deserves. From winter dormancy, foliage emerges in early spring, and the narrow, strappy leaves resemble those of the true lily from a distance. In April and May, clusters of powder-blue, star-shaped flowers appear atop stems that grow 2-3 feet tall.
Terminal flower clusters are made up of dozens of individual blossoms.
During summer, the bright green foliage makes a nice backdrop for later flowering plants, and the waving, feathery stalks provide nice movement in the garden. I have a handful of these running in a curved line through a front garden bed, because in addition to their gorgeous early flowers, blue star does this in the fall:
absolutely spectacular as a mass planting