Balloon Flower

I believe it is Campanula (bellflower) but do not know which. They are so many. I have several varieties.

Thank you. You sent me in the right direction. I'm fairly certain it's Campanula Rotundifolia.

Bathgate, I think your bellflower is Platycodon grandiflorus I looked at it on internet. It is also called balloon flower or Chinese (or Japanese) bellflower.
It is the bud which looks like a balloon which gave me the hint .Campanulas have a different flower bud. Sorry that I sent you the wrong direction. Let me know what you think.

Thanks for checking on that Klahanie. I really appreciate it.