There are a number of species of Cobaea. C. scandens being the most familiar. Some 20 years ago Harry Hay gave me a seedling of Cobaea pringlei from Mexico which turned out to be rather a nice climber. The down side is it is a short day flowering plant so it doesn't start to flower until very late in the season. The buds are forming now. Often this means in the UK that it doesn't flower for long before it is frosted. On the positive side it is fairly hardy. I have kept it going for all these years. It has thick fleshy roots and is completely herbaceous here in London.
