This section is from the book "Who's Who Among The Wild Flowers", by W. I. Beecroft. Also available from Amazon: A Field Guide to Edible Wild Plants.
Flat Top.
Vernonia noveboracensis. Composite Family. July - Sept.
Found in moist soil, meadows. Massachusetts to Virginia and Mississippi; usually near the coast.
Reddish purple, the brownish purple scales bristle tipped, in broad, flat clusters terminating stem 3 - 9 feet high.
Long lance-shaped, toothed.

Ironweed.
 
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