I had no hope of puzzling this crowd. The plant is, indeed, a teasel. It was used in the oulden tymes to card wool for spinning. The stem and the seedhead are covered with stiff spikes. Harvesting and using cannot have been fun.
The Knockando Wool Mill in Scotland has a nice blog post on the plant and its use. She includes a picture of a very large carding wheel covered with secured teasel seedheads. The link is here. This is a picture of their carding wheel.
In my search for information, I discovered I had purchased a biennial which had apparently not set seed. So funny that I carefully planted it in a metal mesh so the voles would leave it alone. Some kind of plan "B" will need to happen by spring 2017.
A more manageable handtool that uses teasels is just a mere Google image search away. See below.
There seems to be a lot of chicken and egging going on in the deep Web about teasel being the root of teasing something apart vs teasing something apart being the root of teasel. I leave the solution as an exercise for the student.