Diablo jewelflower,[2] is a rare species of flowering plant in the mustard family.

It is endemic to Contra Costa County, California, where it is known from fewer than 15 occurrences on and around Mount Diablo.

It is threatened by habitat degradation, such as trampling by hikers and destruction during maintenance activities.

[3] Streptanthus hispidus is a bristly annual herb growing up to 30 centimeters tall.

The bristly bell-shaped calyx of sepals is greenish brown in the fertile flowers and purple in the sterile.