[Wikipedia] Range, Habitat, Threats: Streptanthus morrisonii is an uncommon species of flowering plant in the mustard family known by the common name Morrison's jewelflower.[2] It is endemic to California, where it is known from the North and Central Coast Ranges. It is limited to serpentine soils in chaparral and forest habitat. It is considered a species complex which includes Streptanthus brachiatus.[3] S. morrisonii is divided into four subspecies and is variable. Threats to this species include boron toxicity from the steam of nearby geothermal power plants.[4] (link added by Mary Ann Machi)