The Solanaceae family of plants provides edible fruit (i.e., tomatoes, husk tomatoes, chili peppers, eggplant), tubers (i.e., potatoes), and plants used for leisure activities (i.e., tobacco) that are useful to humans. Several wild members of this family grow in the U.S. Southwest and some were eaten by the Ancestral Puebloans. We present evidence here that the Ancestral Puebloans in the Four-Corners region of the U.S. Southwest–the states of Arizona, Colorado, New Mexico, and Utah–were actively cultivating the tubers of Solanum jamesii to supplement their diets of domesticated corn (Zea mays), beans (Phaseolus sp.), and squash (Cucurbita sp.). This is supported by modern day Native American groups who have used this plant for food either now or in their recorded past. We also propose that this potato tuber was cultivated or allowed to grow in gardens or fields around some major population centers in Puebloan times and that the stands currently growing in or near some of those archaeological habitation sites are legacy stands directly descended from ancient efforts to manage the tubers for food. The plant's location at the northern limits of its current range offers support for this proposal. This potato tuber would have provided a dependable and excellent source of nutrition for the ancestral Puebloans as well.