Thistle growing in a pasture, sandy soil, full sun, coastal SC. Largest plants are over 6 feet tall. Largest leaves are approx 14 inches in length. Underside of leaves are paler shade of green than topside. Photographed 5-29-17. Most plants did not yet have open flowers.
Hi Ann, I answered this some time ago. Please scroll down.
–Steve Hill, Botanist, SCNPS