Medium to large plant, 2 to 8 feet tall. Stems bristly hair. Long, narrow, pointed, untoothed leaves clasp the stem. Flowerheads large, 1 to 2 inches wide, with many deep purple (rarely rose to white) rays and yellow discs, turning purple. Blooms in autumn.

Perhaps our most beautiful aster, a native of damp meadows. Formerly rare in the Park, along what is now the Riverway bikepath. Has not been seen in years and may now be extinct in the Park.

Smooth aster (S. laeve) has smaller flowers and smooth stems and likes drier conditions. New York aster (S. novi-belgii) has very narrow leaves and somewhat smaller flowers with fewer rays. Other asters in the Park have white or pale flowers or heart-shaped leaves..