The blue stars, originating from North America, Japan and the Mediterranean, provide in late spring through into summer, blue-sky starry flowers on delicate stems. For contrast their emerge from darker, dusky buds. Foliage is often narrow and can produce golden autumnal tones. It's part of the Apocynaceae family, so can produce a milky sap (wear gloves when handling) when stems or leaves are broken. Amsonia is named after Charles Amson, an 18th century, scientific American explorer.
Small bees and flies visit the flowers for nectar and pollen but the presence of toxic sap restricts the use of its leaves by herbivorous insects.