Flat-topped White Aster flowers in July, much earlier than most Asters, with clusters of white petals and yellow center disks. It is rhizomatous, meaning it spreads by underground rhizomes as well as by seed. A wide variety of pollinators are attracted to the nectar and pollen of the flowers. These species include long- and short-tongued bees, wasps, flies, beetles and butterflies. Plants host caterpillars of the Pearl Crescent Butterfly, Harris Checkerspot Butterfly and several species of moths.