Flower:

Branching clusters of stalked flowers at the top of the stem and arising from upper leaf axils. The wiry branches are often erect or nearly so. Flowers are 1 to 1¼ inches across, 15 to 25 purple petals (ray flowers) and pale yellow center disk flowers that turn dull reddish brown with age.

The bracts (phyllaries) surrounding the base of the flower are in 3 to 5 layers, densely covered in silky hairs, the outer phyllaries with spreading, broadly egg-shaped tips about ¼-inch long and the inner narrowly triangular to lance-linear with a sharply pointed tip. Flower stalks are up to 1¼ inch long, slender, densely covered in soft, appressed hairs, with a few to several leaf-like bracts below the flower.

Leaves and stem:

Leaves are generally oblong-elliptic, toothless, stalkless, blunt or pointed at the tip, and densely covered in long, fine hairs that give them a silky feel and silvery sheen, and is where the plant gets its common names. Leaves in the upper part of the plant are mostly ascending to erect, ½ to 1¼ inches long and up to ½ inch wide.

Basal and lower stem leaves are much longer and most wither away by flowering time. Stems are single or multiple from the base, wiry and delicate, hairless near the base, densely covered in fine appressed hairs in the upper plant, and may initially be green but are typically brown.

Fruit:

Fruit is a brown seed with a tuft of light brown hair to carry it off in the wind. The seed head is ½ to ¾ inch across.

Notes:

Silky Aster most closely resembles Aromatic Aster (Symphyotrichum oblongifolium), which has rough leaves, narrow phyllaries, and a bright yellow center disk. Silky Aster starts emerging around May; it's characterized by a clump of narrow leaves densely covered in long, soft hairs.