Petalonyx thurberi
 Petalonyx thurberi is a species of flowering plant in the family Loasaceae known by the common names Thurber's sandpaper plant and common sandpaper plant. It is native to the deserts of the southwestern United States and northwestern Mexico where it grows in sandy and scrubby habitat. It is a rounded or spreading clumpy subshrub made up of many rough-haired stems approaching one meter in maximum height.