Peanut. Moche Culture 300 A.D. Larco Museum, Lima, Peru.
The domesticated peanut is an amphidiploid or allotetraploid, meaning that it has two sets of chromosomes from two different species, thought to be A. duranensis and A. ipaensis. These likely combined in the wild to form the tetraploid species A. monticola, which gave rise to the domesticated peanut.
This domestication might have taken place in Paraguay or Bolivia, where the wildest strains grow today. In fact, many pre-Columbian cultures, such as the Moche, depicted peanuts in their art.
Archeologists have (thus far) dated the oldest specimens to about 7,600 years found in Peru . Cultivation spread as far as Mesoamerica where the Spanish conquistadors found the tlalcacahuatl (Nahuatl = "cacao", whence Mexican Spanish, cacahuate and French, cacahuète) being offered for sale in the marketplace of Tenochtitlan (Mexico City).
The plant was later spread worldwide by European traders.
The legume 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 around 1800.