Those horrible things are called Canadian Thistle. They are impossible to get rid of unless you have a product called Curtail. It is something like roundup, that is concentrated and you mix it with water and spray the thistle. It gets rid of it and it wont come back. If you pull thistle, or use round up, it doesn't work, and will keep spreading and coming back. The Curtail is not found at the usual stores. You have to get it from your County Agricultural Agent, who either will have some, or can get it for you. It is a bit pricey, but it is so worth it! I used to have thistle all over the yard, and now I have had none for years thanks to Curtail. It is a red liquid, by the way, and does not harm grass. People in your area who deal with fertilizing for farms will have access to this also. Good luck, and it is sooo worth it.