There is a ornamental plant called "potato vine" that is not a potato. I'd have to look to see whether it's a solanaceae member, which it might be. The flowers are purple.I have seen that potato vine is a common addition to flower arrangements but I'm amazed that you harvested potatoes from a pot I think that is my favorite urban gardening story of all time!!!
I can see potato plants looking very pretty in pots, but I don't think they are truly ornamental over an entire season, personally.