Streptanthus oliganthus is an uncommon species of flowering plant in the mustard family known by the common name Masonic Mountain jewelflower.

Its habitat includes forest, woodland, sagebrush, and mountain talus.

It is a rhizomatous perennial herb producing a hairless, waxy, usually unbranched stem up to about 40 or 50 centimeters in maximum height.

The basal leaves have lance-shaped, smooth-edged blades up to 10 centimeters long borne on fuzzy to rough-haired petioles.

The fruit is a smooth, flat, straight or slightly curved silique up to 8 to 10 centimeters long.