Sub-category: Aster family
This perennial wildflower is 1.5 to 6 feet tall, branching occasionally along the upper half of its length. The rather stout stems are light green to reddish purple (often the latter), terete to slightly grooved, and evenly covered with stiff spreading hairs. The alternate leaves are up to 6 inches long and 1.75 inches across, becoming gradually smaller along the upper half of each plant; they are narrowly lanceolate to lanceolate with poorly defined remote teeth along their margins. The leaves are yellowish green, medium green, or purple (sometimes the latter color during the fall); they are usually glabrous, except for some hairs along the central veins of their lower sides. Most leaves clasp the stems, although some of the smaller upper leaves are sessile.
The central stem terminates in a panicle of flowerheads; some lateral stems may produce smaller panicles of flowerheads. The branches of each panicle are ascending and usually hairy. Along these branches, there are linear-lanceolate leafy bracts up to 1 inch long. The outer branches terminate in flowerheads about 0.75 to 1.25 inches across, consisting of 30 to 50 ray florets and a similar number of central disk florets. The petal-like rays are usually lavender, pale blue-violet, or purple (less often white); they are widely spreading and very slender. The tubular disk florets are 5-lobed; they are initially yellow, but later become dull red. At the base of each flowerhead, there are several overlapping bracts that are linear in shape, green, and hairless; they are rather loosely assembled around the base of the flowerhead and slightly spreading.
Habitats include soggy thickets along streams, open swamps, fens and calcareous seeps, sedge meadows, and other wetlands. Blooms August through October.