Symphyotrichum patens is a perennial herb 20-150 cm, from a root crown, stems hairy, slender, rather brittle.
Leaves alternate, oblong, 2.5-15 cm long, 0.8-4.5 cm wide, base lobed, clasping stem, soon deciduous.
Flowers blue, rays 15-25, 0.8-1.5 cm, disk flowers yellow, radially symmetrical, bracteate base of flower head 0.5-0.9 cm long, overlapping in 3-4 rows, hairy-glandular, papery, blooming Aug.-Oct.
Fruit dry, 1-seeded, achene, with tuft of hairs (pappus), wind dispersed.
Wetland status: UPL.
Frequency in NYC: Very infrequent.
Habitat: Dry, open woods.