See image under musk thistle. Flower surrounded by narrow bract leaves. Blooms in June through August. See image under plumeless thistle . Flower surrounded by purplish, flat, pointed bract leaves.
Leaves are wavy.
Blooms in July through September. See image under Canada thistle. Flower bract leaves are slightly hairy and have a long, sharp spine. Prickly wings on stem. Underside of leaf is green.