This native perennial plant is 2-3½' tall and little branched, except near the inflorescence. It is initially erect, but often leans over as a result of the heavy inflorescence. The stems are usually green with lines of white hairs; sometimes they are dull purplish red. The alternate leaves are up to 3½" long and 2" across, becoming smaller as they ascend the stems. These leaves are cordate in shape and serrate along the margins. Their petioles are up to 1" long and conspicuously winged. The upper surface of these leaves is nearly hairless or covered with sparse short hairs, while the lower surface is glabrous, except for a few hairs along the major veins. The upper stems terminate in large panicles of compound flowers. These panicles are usually longer than they are wide; they are pyramidal or oblong, rather than flat-topped. Each compound flower is up to ½" across, consisting of about 8-18 lavender or light blue ray florets and a similar number of disk florets. The disk florets are initially cream or light yellow, but become reddish purple with maturity. The floral bracts are narrowly lanceolate, appressed together or slightly spreading, and have dark green tips that are more or less diamond-shaped. Sometimes the tips of the floral bracts assume a reddish tint in bright sunlight. The blooming period occurs from late summer to the fall and lasts about 2 months. The achenes have small tufts of hair and are distributed by the wind. The root system consists of a caudex and rhizomes. This plants spreads vegetatively and by reseeding itself.