| The peanut gained Western popularity when it came to the United States from Africa. It had become popular in Africa after being brought there from Brazil by the Portuguese.
Evidence demonstrates that peanuts were domesticated in prehistoric times in South America, where wild ancestors are still found. Cultivation spread as far as Mesoamerica where the Spanish conquistadors found the tlalcacahuatl being offered for sale in the marketplace of Tenochtitlan (Mexico City), as they are still offered by street vendors there today. The plant was later spread worldwide by European traders. Cultivation in the English colonies of North America was popularized by African Americans, who brought the Kikongo word "goober". In South America, the peanut (called there mani or amendoim in Brazil) is thought to have first grown in Argentina or Bolivia, where the wildest strains grow today. The peanut gained Western popularity when it came to the United States from Africa. It had become popular in Africa after being brought there from Brazil by the Portuguese. The flower of the Arachis hypogaea is borne above ground and after it withers, the stalk elongates, bends down, and forces the ovary underground. When the seed is mature, the inner lining of the pods (called the seed coat) changes color from white to a reddish brown. The entire plant, including most of the roots, is removed from the soil during harvesting. The pods begin in the orange veined, yellow petaled, pea-like flowers, which are borne in axillary clusters above ground. Following self-pollination, the flowers fade. The stalks at the bases of the ovaries, called pegs, elongate rapidly, and turn downward to bury the fruits several inches in the ground to complete their development. The pods act in nutrient absorption. The fruits have wrinkled shells that are constricted between the two to three seeds. The mature seeds resemble other legume seeds, such as beans, but they have paper-thin seed coats, as opposed to the usual, hard legume seed coats. Peanuts grow best in light, sandy loam soil. They require five months of warm weather, and an annual rainfall of 500 to 1000 mm (20 to 40 in) or the equivalent in irrigation water. The pods ripen 120 to 150 days after the seeds are planted. If the crop is harvested too early, the pods will be unripe. If they are harvested late, the pods will snap off at the stalk, and will remain in the soil. Peanuts are particularly susceptible to contamination during growth and storage. Poor storage of peanuts can lead to an infection by the mold fungus Aspergillus flavus, releasing the toxic substance aflatoxin. The aflatoxin producing molds exist throughout the peanut growing areas and may produce aflatoxin in peanuts when conditions are favorable to fungal growth. |