Smooth Aster (Symphyotrichum laeve) has leaves that are smooth to the touch, distinguishing it from most other Aster varieties. The stem also often takes on a shade of blue. This is a non-aggressive plant that is slow to spread so it is a nice one to have in the garden with companions. The beautiful purple-blue flowers attract many different pollinators and the plant is host for the Silvery Checkerspot and Pearl Crescent Butterflies.