Plagiobothrys collinus is a species of flowering plant in the borage family known by the common name Cooper's popcornflower. It is native to California, Arizona, and parts of northern Mexico, where it can be found in many types of habitat. IPlagiobothrys collinus is an annual herb with a spreading or erect stem 10 to 40 centimeters in length. The leaves along the stem are 1 to 4 centimeters long, the lower ones oppositely arranged and the upper ones alternate.