Population

New York Ironweed,
Vernonia noveboracensis

Asteraceae or Sunflower Family

Tall herb, 3-10 feet tall.  Leaves lance-shaped, finely toothed, not opposite each other.  Flowers tiny, tubular, 5-parted, deep red violet to blue violet, 30 to 50 in a flowerhead.  Flowerheads in loose clusters.  Blooms in late summer.

A beautiful native plant of damp places; occasional in open sunny moist places in the Park.

Sometimes confused with Joe-Pye weed (Eupatorium fistulosum), but that plant has paler flowers which are much smaller and much more crowded, and leaves in whorls of 3-7.

 

Plant
Flowerheads
Closeup of flower heads
Flowerheads
Leaves   Stem with leaves