Yep they're as bad as dandelions but dandelions aren't lethal. I use to collect a few when I was out trying to find wild things for basketweaving. They dry just as pretty and you can tape some of the stem to a better stem. I'm just older now and don't have that kind of energy or time.I love the look of thistle too. I had one pop up in my leopard yard a few months ago and I left it there so I could see the pretty flowers, but when it went to seed I quickly clipped the heads off so it wouldn't re-seed itself. Man, those things are lethal!