The humble potato is a tuber originally cultivated in Peru. When properly prepared potatoes can satisfy (almost) all human nutritional needs. The potato was responsible for the health of the Irish population during past centuries. Unfortunately, over reliance on potatoes resulted in widespread famine when potatoes crops failed.
Handy Links:
Wiki page about potatoes: Link
Wiki page about Irish Potato Famine: Link
Agricultural Potato Advocacy Group: Link
Potato Salad Recipe: Link