Willowleaf Aster (Symphyotrichum praealtum)

Willowleaf aster, like other asters and goldenrods, is an important nectar source for migrating monarch butterflies and other pollinators. Small yellow disk florets are surrounded by the lavender petals of the ray florets. It is similar in size to New England Aster, but it spreads by underground rhizomes and is more aggressive. Because of its ability to spread, it often forms dense colonies.