A flower with a difference

My Plant Snap app failed yet again to identify this plant. It kept suggesting it was a sunflower. (In fact this plant snap app is a big disappointment, all too often it gets it wrong.)
 
So I had to resort to the old fashioned way of research – opening a book- in this case the Royal Horticulture Society Encyclopedia of Plants and Flowers.
 
And there it was- helianthus multiforus.  We have had this plant several years and it has grown huge, well about 4ft and is taking over an herbaceous border. However, neither M nor myself can remember where we bought it.
 
   
And now for something completely different