I have found this growing and flowering rather nicely in my garden. About 90-100 cm tall, beautiful color, long flowering period. Appears to be biennial. And I have some memory of buying Adenophora latifolia. However, this seems a little too tall for this particular species? Do please help.
Are you sure that the plant is so high and that it is Adenophora? This plant looks very much like Campanula rapunculoides. But in this case it would be a perennial spreading with rhizomes and not usually higher than 70 or 80 cm.
At the attached link is the description of a way to distinguish adenophora from campanula. (Go to the attached link, then open the retail catalogue portion and scroll down to the heading "Adenophora".) http://gardensnorth.com/site/
Well, a friend of mine bought seeds and grew identical plant, seeds were of A.latifolia. And the plant died after flowering, same as in my garden. The two look almost identical, though. R.
The problem is, distinguishing Adenophora from Campanula is easy, if the plant is still in flower (mine is not, but this spectacular ring at the base of ovary was there). But how to distinguish between different species? Anybody has seen a key? R.