Potato

The potato is a starchy vegetable that grows underground on the roots of a leafy plant. The plant belongs to the nightshade family, which also includes tomatoes and peppers. The part people eat is called a tuber, a swollen piece of underground stem where the plant stores food. Today, the potato is the fourth most important food crop in the world, after corn, wheat, and rice.

Potatoes first grew wild high in the Andes Mountains of South America. People living there began farming them more than 7,000 years ago, long before the pyramids of Egypt were built. The Inca Empire grew hundreds of kinds of potatoes in cool mountain fields. Inca farmers even invented a way to freeze-dry them. They left the potatoes outside on cold nights and stomped on them in the morning sun. The dried potatoes, called chuño, could be stored for years.

Spanish explorers brought potatoes back to Europe in the 1500s. At first, many Europeans were afraid to eat them. Some thought the plants were poisonous, which is partly true. The leaves and green parts contain a chemical that really can make people sick. Only the tuber is safe to eat. Once people figured this out, potatoes spread across Europe and changed history. They were cheap to grow and packed with energy, so populations grew quickly wherever potatoes were planted.

That same success led to a terrible disaster. In the 1840s, almost everyone in Ireland depended on a single type of potato. Then a disease called potato blight rotted the crop in the fields. About one million people died of hunger, and another million left Ireland for other countries, including the United States. Today, farmers plant many different kinds of potatoes to help prevent that kind of collapse.

A potato plant grows from another potato. Farmers cut a potato into chunks, making sure each chunk has an "eye," which is a small bud. The eye sprouts into a new plant. After a few months, the plant grows new tubers underground. China grows more potatoes than any other country, followed by India and Russia. Worldwide, farmers harvest about 400 million tons of potatoes each year.

Potatoes are mostly water and starch, but they also have vitamin C, potassium, and fiber, especially in the skin. People eat them baked, boiled, mashed, roasted, and fried. The next time you eat french fries, you are tasting a plant that climbed down from the Andes and traveled all the way around the world.