Strange plant

A strange plant has appeared in the garden. I have never seen it like, nor did I put it in. Any ideas please.

 It has curved spines down the back of the leaves in the middle.

It's a teasel http://en.wikipedia.org/wiki/Dipsacus Could it have come from some wild bird seed or wildflower mix of seeds?

I'm struggling to get some to germinate in my garden 

I agree it's a teasel - a friend gave me one last year - a lovely plant, particularly the seed head which is liked by both flower arrangers and birds. I had hoped I would get self-sown seedlings this year but none have appeared.

They seem to germinate freely along a walking route near us on a disused railway !!!! Such are the vagaries of nature !!! 

I bought one a few years ago & hoped it had self seeded. It had, in a crack in the drive. I've brought a couple home from the lotty. The bees absolutely loved it. I watched one going round & round for over an hour. They can be a nuisance but any not required are easily pulled out.

I grew one last year from a small plant. It ended up 7ft tall! The birds and bees loved it, but I have seedings coming up in my lawn, dozens of them, also in between the slabs on the patio. It must have been from when I cut it down at the end of the season. I thought the seeds had all been eaten but obviously not!

Thanks every one.