The potato is a starchy, tuberous crop from the perennial nightshade Solanum tuberosum. In many contexts, potato refers to the edible tuber, but it can also refer to the plant itself. Common or slang terms include tater and spud. Potatoes were introduced to Europe in the second half of the 16th century by the Spanish. Today they are a staple food in many parts of the world and an integral part of much of the world’s food supply. As of 2014, potatoes were the world’s fourth-largest food crop after maize (corn), wheat, and rice.
Wild potato species can be found throughout the Americas, from the United States to southern Chile.The potato was originally believed to have been domesticated independently in multiple locations, but later genetic testing of the wide variety of cultivars and wild species traced a single origin for potatoes. In the area of present-day southern Peru and extreme northwestern Bolivia, from a species in the Solanum brevicaule complex, potatoes were domesticated approximately 7,000–10,000 years ago. In the Andes region of South America, where the species is indigenous, some close relatives of the potato are cultivated.
Following millennia of selective breeding, there are now over 1,000 different types of potatoes. Over 99% of presently cultivated potatoes worldwide descended from varieties that originated in the lowlands of south-central Chile, which have displaced formerly popular varieties from the Andes.
The importance of the potato as a food source and culinary ingredient varies by region and is still changing. It remains an essential crop in Europe, especially eastern and central Europe, where per capita production is still the highest in the world, while the most rapid expansion in production over the past few decades has occurred in southern and eastern Asia, with China and India leading the world in overall production as of 2014.
Being a nightshade similar to tomatoes, the vegetative and fruiting parts of the potato contain the toxin solanine and are not fit for human consumption. Normal potato tubers that have been grown and stored properly produce glycoalkaloids in amounts small enough to be negligible to human health, but if green sections of the plant (namely sprouts and skins) are exposed to light, the tuber can accumulate a high enough concentration of glycoalkaloids to affect human health.
Potatoes are prepared in many ways: skin-on or peeled, whole or cut up, with seasonings or without. The only requirement involves cooking to swell the starch granules. Most potato dishes are served hot but some are first cooked, then served cold, notably potato salad and potato chips (crisps). Common dishes are: mashed potatoes, which are first boiled (usually peeled), and then mashed with milk or yogurt and butter; whole baked potatoes; boiled or steamed potatoes; French-fried potatoes or chips; cut into cubes and roasted; scalloped, diced, or sliced and fried (home fries); grated into small thin strips and fried (hash browns); grated and formed into dumplings, Rösti or potato pancakes. Unlike many foods, potatoes can also be easily cooked in a microwave oven and still retain nearly all of their nutritional value, provided they are covered in ventilated plastic wrap to prevent moisture from escaping; this method produces a meal very similar to a steamed potato, while retaining the appearance of a conventionally baked potato. Potato chunks also commonly appear as a stew ingredient. Potatoes are boiled between 10 and 25 minutes, depending on size and type, to become soft.