Looks like Eupatorium cannabinum, Hemp Agrimony (Eupatorium cannabinum)
but there could be other look-a-likes in your region, where is the plant growing?
Maybe Eupatorium perfoliatum, most pictures on the web show them with white flowers, but there seem to be pinkish too, not sure about the leaves though, its hard to see the details on the photo.. http://ontariowildflowers.com/...
