Aster family (Aster family)
Description: This native perennial plant is 1-2' tall, often sprawling along the ground. The wiry stems branch occasionally, and have a tendency to zigzag between the leaves. They are whitish green or silver and covered with a fine pubescence when young, becoming brown and bare when old. The alternate leaves are silvery green and have a silky appearance as the result of a dense coating of fine hairs. They are about 1½" long and ½" wide, lanceolate or ovate, and sessile. Their margins are smooth.
The daisy-like composite flowers occur in small clusters at the terminus of major stems. They are about 1¼" across, consisting of 12-25 ray florets that are lavender to violet-blue, and numerous central disk florets that are golden yellow. There is no noticeable floral scent. The blooming period occurs during the fall and lasts about a month. The achenes develop small tufts of hairs, and are dispersed by the wind. The root system forms a short caudex on mature plants and some fibrous roots. Occasionally, vegetative offsets are formed.
Cultivation: The preference is full sun and dry conditions. Almost any kind of soil is satifactory if the site is well-drained, but this plant typically grows in poor soil that is rocky or sandy. A high pH is tolerated. Overall, this plant develops more slowly than most and is a bit more difficult to grow. It doesn't like too much competition from taller, more aggressive plants. The drought tolerance of mature plants is excellent, although some of the lower leaves will drop from their stems. Foliar disease doesn't seem to bother it.
Range & Habitat: Silky Aster occurs primarily in the northern tier of counties, and in many counties along the Illinois and Mississippi Rivers. It is an uncommon plant that appears to be declining in numbers as a result of habitat destruction. Habitats include dry gravel prairies, dolomite prairies, sand prairies, hill prairies, scrubby barrens, limestone glades, and prairie remnants along railroads (rarely). This is an indicator plant of high quality habitats in dry areas.
Faunal Associations: Little information is available for this plant. Like other asters, many kinds of insects probably visit the flowers, especially bees, and to a lesser extent small butterflies, skippers, and Syrphid flies. Among the bees, Green Metallic bees are freqent visitors. The Syrphid flies probably feed on pollen and are non-pollinating. Mammalian herbivores eat this plant readily, especially rabbits and groundhogs. Its small size may partially exempt this plant from the attention of large herbivores, such as deer.
Photographic Location: The photograph was taken at the webmaster's wildflower garden in Urbana, Illinois.
Comments: This is a truly beautiful little plant with attractive foliage and flowers. It's an excellent candidate as a wildflower in a rock garden. Silky Aster can be distinguished from all other asters by its exceptional foliage, which has a silvery or silky appearance because of the numerous fine hairs covering the stems and foliage.