Polly, they're typically handled by bulb suppliers, and kind of behave like a lot of bulb plants in the way they go dormant, storing food for next season's growth. Imported ones with the roots removed appear very bulb like, although I think that practice is detrimental to the plant. The roots are so fat and fleshy, I would think there's energy stored there as well as the central tuber- I wonder if that has to do with the issues removing them? Mamajack was asking on another Cubit if they're ever offered as a potted plant, which is something I've never seen.
