A wildflower or weed

I saw this today in a wide open field when I was walking the dog.  I think I had found the name of it before at some point but can't find it now.  And it is not in my new wildflower book.   When is something that flowers a wildflower instead of a weed?  Maybe it is a weed and not a wildflower. 

I do love the petals of this flower.   It looks like fairies have drawn outlines of petals on the petals.   

Thanks to Anni for hosting flower friday!