That looks remarkably like a sow-thistle to me, Carohit, and regarded as a weed in my garden and pulled out immediately.

That's what i thought Gattina

I agree. Pull it out and do not compost the flower heads or you will spread it through your garden.

or a milk thistle. either way in Britain it is considered a weed as it is one of our mative wildflowers.

Thanks Gattina, Andy, Scot and Seaburn...the weed is taken care of :)