By Harold McGee
There are more than 200 species of potato, relatives of the tomato, chilli, and tobacco that are indigenous to moist, cool regions of Central and South America. Some were cultivated 8,000 years ago. Spanish explorers brought one species, Solanum tuberosum, from Peru or Colombia to Europe around 1570. Because it was hardy and easy to grow, the potato was inexpensive and the poor were its principal consumers. (An Irish peasant ate 5–10 pounds per day at the time of the 1845 blight.) It now leads all other vegetables in worldwide production. More potatoes are consumed in the United States than any other vegetable, around a third of a pound/150 gm per person per day.