Aster family (Asteraceae)
Description: This native perennial plant is up to 2' tall, branching occasionally to create a bushy appearance. The hairy stems are green initially, but often become brown when the plant matures. The alternate leaves are up to 3" long and ¼" across toward the base of the plant, becoming less than 1" long and 1/8" across near the flowering stems. They are linear in form and have smooth edges, often with a fine pubescence. The lower leaves usually shrivel and fall off by the time the compound flowers bloom during the fall. These flowers are very numerous and have a daisy-like appearance. Each compound flower is a little less than ½" across, and consists of numerous yellow disk florets, which are surrounded by about 12 white ray florets. There is no noticeable floral scent. There are numerous needle-like green bracts on the flowering stems, giving this plant a heath-like appearance. The little seeds have tufts of white hairs, and are distributed by the wind. The root system is rhizomatous.
Cultivation: The preference is full sun and average to dry conditions. The soil can contain significant amounts of loam, clay, or gravelly material; alkaline soil is tolerated. This plant withstands drought. It often spreads vegetatively to form colonies, especially in open disturbed areas.
Range & Habitat: The Heath Aster is found in most counties of Illinois, but is absent from some counties in the western and SE areas of the state (see Distribution Map). Overall, it is occasional to locally common. Habitats include mesic to dry black soil prairies, gravel prairies, dolomite prairies, hill prairies, savannas, openings in dry rocky forests, limestone glades, areas along roadsides and railroads, and pastures. It can be found in both high quality habitats and disturbed areas.
Faunal Associations: A wide variety of insects are attracted to the flowers, including long-tongued bees, short-tongued bees, wasps, flies, butterflies, skippers, moths, beetles, and plant bugs. Bee visitors include honeybees, bumblebees, cuckoo bees, little carpenter bees, leaf-cutting bees, Halictid bees, plasterer bees, and Andrenid bees. Wasp visitors include thread-waisted wasps, bee wolves, spider wasps, sand wasps, paper wasps, Ichneumonid wasps, and Braconid wasps. Among the flies, are such visitors as bee flies, Syrphid flies, thick-headed flies, Tachinid flies, Muscid flies, and others. Various insects suck juices from the plant, including aphids, lace bugs, and plant bugs. The caterpillars of the butterfly Chlosyne nycteis (Silvery Checkerspot) feed on the foliage or flowers, as does the caterpillars of many moth species (see Moth Table). Wild Turkeys nibble on the seeds and foliage to a limited extent. Mammalian herbivores, including the White-Tailed Deer, Cottontail Rabbit, and various kinds of livestock, also feed on the tender growth of young plants occasionally, but are less likely to bother mature plants later in the year.
Photographic Location: The photographs were taken at Loda Cemetery Prairie in Iroquois County, Illinois.
Comments: The Heath Aster has a wide distribution, and there is some variability in regards to its size and appearance across different locations. Sometimes it will hybridize with other species of asters, such as Aster pilosus, making identification difficult. The Heath Aster differs from other asters with small white flowers primarily by its short, narrow leaves (never more than 3" long and ¼" across). Also, its flowers tend to be smaller in size and have fewer ray florets (about 12) than many other species.