Many of the potatoes grown at high altitude in Peru/Bolivia in the past had naturally toxic levels of alkaloids. That's why they natives processed them to make chuno http://en.wikipedia.org/wiki/Chu%C3%B1o. Today mainly non-toxic varieties of potato are grown there, but they still make chuno because they have got used to it, and because it allows easier long-term storage. I think it's horrible.

The so-called "Irish potato" refers to those varieties of potato that can be grown at higher latitudes. Typical Andean varieties don't tolerate the day-length patterns at higher latitudes. It was only once a variety tolerant of long summer day-lengths was accidentally created that potato-growing became common in more northerly places. More usually once economically useful crops were discovered by Europeans in their colonies, they spread round the world like wild-fire (see eg chilli, sweet potato, maize, etc). I wonder whether the potatoes grown from potato seeds would retain their tolerance for long summer day-length.