The Irish discovered, it is possible to sustain yourself and even thrive on a diet made up entirely of potatoes.
During the 1700's and 1800's the Irish ate potatoes because that's what they could grow in their rocky, cold, poor soil. They made the mistake however, of not including a little diversity in their planting. When the blight began to spread in the 1840's it spread to all the fields growing the same kind of potatoes. Irish or white potatoes (Solanum tuberosum) originated in the Andes Mountains of South America.
Frankly it's amazing that so many plants came from a place where the soil is poor and the temperatures fluctuate between extremes. The tough pre-Columbian farmers discovered and cultivated potatoes some seven thousand years ago. When the Conquistadors tramped through Peru in the 1500's, they began the transport of potatoes to the far corners of the world.
See: Irish Potatoe Famine
