Southwestern prickly poppy. "these are 3-5 inches across, white with yellow centers"

''Argemone pleiacantha'' is a species of flowering plant in the poppy family known by the common name southwestern prickly poppy. It is native to Arizona and New Mexico in the United States and Chihuahua, and Sonora in Mexico, where it occurs in dry woodlands and slopes of foothills and mountains.