This Amsonia is from the Ozark region of the USA, a massive area that resembles Scotland on triple strength Irn Bru.
Here A. illustris grows very happily on gravel bars alongside streams. It's very easy to grow in the UK in moist, loamy soils that are well drained. It will cope with full sun but is best in light shade.
A. illustris resembles A. tabernaemontana but the willow shaped leaves are leathery and shiny. The clusters of light blue flowers are larger. Amsonias are not big blousy showstoppers but refined and elegant troupers that are hardy, reliable and relatively trouble free.
Their sap contains a milky latex which keeps slugs off emerging shoots. Once established Amsonia rarely need attention which makes them the perfect garden plant.
Moist well drained
Full sun, partial shade