Common michaelmas daisy

Symphyotrichum × salignum, sometimes known as willowleaf aster, is a naturally occurring hybrid perennial herb of the family Asteraceae, derived from crosses between Symphyotrichum lanceolatum and S. lateriflorum and occurring sporadically wherever the parents grow together in eastern and central North America. The plant typically grows 0.5–1.5 m tall from creeping rhizomes, producing erect, slender, glabrous to sparsely pubescent stems that branch in the upper portion. The leaves are alternate, sessile or nearly so, narrowly lanceolate to linear-lanceolate, 5–15 cm long and 0.5–1.5 cm wide, with entire or remotely toothed margins, intermediate in character between those of the two parent species. The numerous small flower heads, 8–15 mm across, are borne in open, somewhat one-sided panicles; each head has 12–25 white to pale lavender ray florets surrounding a centre of yellow disc florets that turn purplish-red with age. Flowering occurs in late summer and autumn. The fruits are small, ribbed achenes bearing a pappus of fine, off-white capillary bristles for wind dispersal.