This atlas describes the ecogeographic distribution of wild potatoes. They occur solely in the Americas, from the southwestern United States to central Argentina and Chile. To help the nonspecialist to understand the past and future changes in their classification, we first discuss the habitats, morphology, and taxonomy of wild potatoes. This is followed by a discussion of problems of data and information quality associated with the locality databases that were used for the maps in this atlas. Distribution maps are provided for all species and series (a taxonomic level that groups related species). Finally, statistics on ecogeographic distribution of wild potatoes, and analytical maps of species richness and series richness are provided.