Centaura montana.

I never cease to be amazed by the colour of this - and the shapes!

I like it, too, and went off to buy a white version. I am SOOO annoyed because guess what - its buds are just opening - BLUE! I complained to the Nursery and I have to take it back, but ring first to see if they've got a really, truely white one! Trouble is, it was on one of my trips out to Devon - a long way just to play swapsies!