Pretty and tasty too, the bellflower plant (Campanula) is a perennial with delightful blossoms which are edible as also are the leaves:
With this plant, however, it is hard to find any leaves. I bought this Campanula Get Mee from Trader Joe's grocery store in Riverside, CA. The botanical name is Campanula Portenschlagiana. To me that both looks and sounds like something that ought to be sprinkled over whipped cream.
Quick before this one dies, for I am the world's worst dirt gardener, I need to get some slips started. Once my cuttings have rooted so that future generations of my new plant are secure, then I will attempt to transfer the whole thing to hydroculture.
I think this one would be very pretty in an AeroGarden3 where it is more likely to survive.
In the kitchen, it will be handy to pinch off blossoms for munching.