Streptanthus brachiatus is a species of flowering plant in the mustard family known by the common name Socrates Mine jewelflower.

It can be found in chaparral and woodland habitat, often on serpentine soils, in Sonoma, Lake, and Napa Counties.

[3] It is a biennial herb producing a branching stem up to about 60 centimeters in maximum height.

There is a basal rosette of fleshy purple-green leaves around the base, each with a sharp-toothed, widely lance-shaped blade up to 4 centimeters long.

Each has an urn-shaped calyx of keeled yellowish or purplish sepals just under a centimeter long.