Wikify: date=May 2009

The potato is a starchy, tuberous crop from the perennial Solanum tuberosum of the Solanaceae family. The word potato may refer to the plant itself as well. In the region of the Andes, there are some other closely related cultivated potato species. Potatoes are the world's fourth largest food crop, following rice, wheat, and maize.

Wild potato species occur from the United States to Uruguay and Chile. Genetic testing of the wide variety of cultivars and wild species suggest that the potato has a single origin in the area of southern Peru, from a species in the Solanum brevicaule complex. However, although Peru is essentially the birthplace of the potato, today over 99% of all cultivated potatoes worldwide are descendants of a subspecies indigenous to south-central Chile. Based on historical records, local agriculturalists, and DNA analyses, the most widely cultivated variety worldwide, Solanum tuberosum ssp. tuberosum, is believed to be indigenous to Chiloé Archipelago where it was cultivated as long as 10,000 years ago.

The potato was introduced to Europe in 1536, and subsequently by European mariners to territories and ports throughout the world. Thousands of varieties persist in the Andes, where over 100 varieties might be found in a single valley, and a dozen or more might be maintained by a single agricultural household. Once established in Europe, the potato soon became an important food staple and field crop. But lack of genetic diversity, due to the fact that very few varieties were initially introduced, left the crop vulnerable to disease. In 1845, a plant disease known as late blight, caused by the fungus-like oomycete Phytophthora infestans, spread rapidly through the poorer communities of western Ireland, resulting in the crop failures that led to the Great Irish Famine.

The annual diet of an average global citizen in the first decade of the twenty-first century would include about 33 kilograms (or 73 lbs.) of potato. However, the local importance of potato is extremely variable and rapidly changing. The potato remains an essential crop in Europe (especially eastern and central Europe), where per capita production is still the highest in the world, but the most rapid expansion of potato over the past few decades has occurred in southern and eastern Asia. China is now the world's largest potato producing country, and nearly a third of the world's potatoes are harvested in China and India. More generally, the geographic shift of potato production has been away from wealthier countries toward lower-income areas of the world.

Etymology

The English word potato comes from Spanish patata (the name used in Spain). The Spanish Royal Academy says the Spanish word is a compound of the Taino batata (sweet potato) and the Quechua papa (potato). This probably indicates that originally, the potato was regarded as a type of sweet potato rather than the other way around, despite the fact that there is actually no close relationship between the two plants at all. Potatoes are occasionally referred to as "Irish potatoes" in the English speaking world, to distinguish them from sweet potatoes. In certain dialects of English, particularly in North America, the words taters, potaters, and tatoes are sometimes used. In some dialects of English spoken in Ireland, potatoes are called praties, which, presumably, comes from prátaí, the plural form of the Irish word for potato, práta.