Answer: I think you are looking at Campanula medium 'Calycanthema' also known as Canterbury Bells or Cup and Saucer. This is a delightful old fashioned biennial. If the flowers seem larger than ordinary, perhaps s/he has a well selected strain or is providing them with excellent growing conditions. Perhaps your neighbor would share some seeds or seedlings with you, or plants are available from Bluestone Perennials. http://www.bluestoneperennials.com/ is their website.
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