Color, purple. Heads of flowers, very large, 2 to 3 inches broad, with leafy bracts below them. Leaves, green both sides, cut into acute, prickly, pointed lobes, the upper sessile, clasping; the lower, petioled. Stem, stout, low, leafy, 1 to 3 feet high, from solid, thick, and much-branching roots. Flowers, fragrant, sometimes white. July to September.
Dry soil, fields and pastures. New England to Delaware and Pennsylvania.