Starch granule evidence for the earliest potato use in North America

Significance Starch granules of Solanum jamesii extracted from ground stone tools establish wild potato use as early as 10,900–10,100 calendar years B.P. in southern Utah. This discovery is the earliest documented use of potatoes in North America, an important energy source that has been largely undervalued or even ignored when diet breadth analyses and optimal foraging theory have been applied in archaeological studies. Younger deposits also contained tools with S. jamesii granules, indicating at least 4,000 years of intermittent use. Ethnographic and historical accounts from the region extend the period of use to more than 10,000 years. Given this long prehistory and history, the question arises as to whether some S. jamesii populations could have undergone transport, cultivation, and eventual domestication over such a long period of time.