Kallstroemia californica is a species of flowering plant in the caltrop family known by the common name California caltrop. It is native to the deserts of the southwestern United States and Mexico. This is a mat-forming annual herb which grows in thick carpetlike masses on sandy substrates. The branching stem has compound leaves which are each made up of several widely-spaced pairs of small oval-shaped green leaflets. It produces individual flowers with five rounded or oval petals and a ring of ten stamens. The fruit is a small body a few millimeters wide of ten conjoined nutlets which split apart.
