Boerhavia coulteri is a species of flowering plant in the four o'clock family known by the common name Coulter's spiderling.

It is native to the southwestern United States and northern Mexico, particularly the desert areas.

This is an annual herb producing an erect or creeping stem up to about 70 or 80 centimeters in maximum length.

The leaves are lance-shaped to somewhat triangular, pointed, sometimes wavy or rippled along the edges, and 5 centimeters in maximum length.

The sticky inflorescence is a small cluster of tiny white to pale pink flowers, each under two millimeters long.