Eriastrum sapphirinum is a species of flowering plant in the phlox family known by the common name sapphire woollystar. This wildflower is endemic to California where it is found in many habitats throughout the state. It is an annual reaching anywhere from 5 to 40 centimeters in height, forming clumps or singular spindly stems. The stem is erect and may be reddish to green, and has the occasional threadlike leaf with sparse hairs to a coat of dense wool.
