Northern Prairie Wildlife Research Center
ASTER FAMILY (Compositae or Asteraceae)
IND. STATUS: OBL
FIELD CHARACTERISTICS: A tall, perennial herb 60-200 cm. high with one to several stems. Leaves are in whorls of 4's and 5's around a purple-spotted stem. The lance-shaped leaves are narrowed to the leaf stalk, serrate, and seldom triple-nerved. Stems are usually not covered with a white waxy bloom. The flattish inflorescence lacks ray flowers. Between 9-22 pink to purple disc flowers occur in each head. Flowers bloom from July through September.
A related, equally common species is boneset (E. perfoliatum), which has white flowers and opposite leaves joined around the stem (perfoliate).
ECOLOGICAL NOTES: Joe-pye weed is a very common composite of sedge meadows and shrub-carrs, particularly on calcareous wet soils. It is also present in fresh (wet) meadows, calcareous fens, and shallow marshes.
SOURCE: Gleason and Cronquist (1991); and Swink and Wilhelm (1994).