By the time the first Europeans arrived in the New World, farmers there were harvesting more than a hundred kinds of edible plants--potatoes, tomatoes, sunflowers, eggplants, avocados, sweet potatoes, peanuts, cashews, pineapples, papaya, guava, yams, manioc (or cassava), pumpkins, vanilla, a whole slew of beans and squashes, four types of chili peppers, and chocolate, among rather a lot else--not a bad haul. It has been estimated that 60 percent of all the crops grown in the world today originated in the Americas.