Frazer: I missed your request for Yacon (Polymnia edulis) earlier. I've grown this for some years and unlike most Andean edibles this isn't daylight sensitive and in a normal summer gives a good crop of tasty (sweet) roots even here in the land of perpetual daylight. Last summer was not normal and I didn't get much of a crop - I grow it as an annual and restart from small nodules on the roots each year. These are also very small, but I should be able to spare at least one and can send in March when it warms up a bit. Please remind me then if you don't find an alternative. Here are a few pictures of the roots (you can't see the nodules) and the very attractive leaves.
