Just seeing this plant in the field behind the parking lot made me twitch. When I was a child on the farm, one of our pastimes was "hunting thistles"--no seriously. You had a hoe and a plastic bag (recycled from something-or-other), and you hoed the thistle down as far as you could, then you put the heads/flowers in your bag (we got to burn them later). If you left any of them they would just grow into more thistles.
There's a tale that involves a scar on my brother's hand, a hoe, and the cattle pond that goes here. ;-) No mud in the world is stickier than the edges of the pond. (Wow, was *I* in trouble--I was old enough to know better. *sigh*)