Symphyotrichum undulatum

Because it is such a late-bloomer (August through November), Wavy Leaf Aster is particularly valuable to a wide variety of pollinators and is especially attractive to native bees. It is also a host to Pearl Crescent caterpillars, and butterflies collect nectar from the loose clusters of pale blue flowers with yellow centers that grow in loose clumps on stems up to four feet tall.