Shining blue star is a striking, smooth perennial, branching and forming clumps. Flowers star-shaped, light blue, clustered in cymes at the tops of stems; the corolla lobes spreading; with a delicate scent. Blooms April–May. Leaves alternate, narrowly lance-shaped, to 6 inches long, leathery, shiny on the upper surfaces. Sap is milky. Fruits narrow seedpods that hang down, about 4 inches long.
Similar species: There are two other Amsonia species in Missouri. Ciliate blue star (A. ciliata) has very narrow, almost threadlike leaves and is uncommon, found in our southern Ozark counties along the Arkansas border. Willow amsonia (A. tabernaemontana), another blue star, has dull leaves (not shiny), and its seedpods are held upright. It is scattered mostly in the southern half of the state.