Wallflower?

I think this is known as a wallflower, but I can't be sure. I don't know whether it is a true wildflower or a garden variety. 

Today, I spent a wonderful day out at Martin Mere with my friend Trish. We spotted a beautiful tawny owl, but it was way up in a tree, and I couldn't get a clear shot of it - a few too many leaves in front of it.