[1] Like other genus members, this herb has wavy petal margins with perimeter calluses that discourage larval herbivory.

The etymology of this genus scientific name derives from the Greek word streptanthus, meaning twisted flower, with reference to the notable wavy margins of the petals.

The Federal Register listing document noted that S. niger occurs only on grasslands above shallow serpentine soils involving gentle to moderate southwestern facing slopes.

The listing statement further notes that: "Serpentine soils are derived from ultramafic rocks such as serpentinite, dunite, and peridotite, which are found in discontinuous outcrops in the...Coast Ranges".

[7] According to the Sacramento Fish and Wildlife Service: "species such as Tiburon jewelflower have adapted to serpentine soils and require them to survive".

An assistant professor from Mills College, with financial support from the Marin Country Open Space District, is carrying out a three year research project on conservation of the species.