General: For most of the year, Fremont's Dalea (Psorothamnus fremontii) is a leafless, bone-white, many branched, mid-sized, tortured shrub (like it had been stomped on and twisted up). During the spring, however, the plant makes up for it by putting on many pinnately compound green leaves and big showy displays of brilliant violet-blue pea flowers. The flowers are arranged in clusters (raceme) about 5 inches long. Each flower produces a short bean pod with a sharp point; one bean (seed) per pod. The fruits have glands on the surface that are green and arranged in longitudinal lines that looks somewhat like the surface of a brain.

Fremont's Dalea is a fairly common component of dry hillsides and bajadas in the Upper Sonoran (Mojave Desert Scrub) life zone and seems to do well on thin soils overlying caliche.

Family: Pea (Fabaceae).

Other Names: indigo bush, Mojave dalia

Plant Form: A finely branched, mid-sized perennial shrub. Spreads from a single stem.

Height: Usually about thigh-high (2-3 feet).

Bark: Gray-green to white. White during most of the year.

Stems: Intricately branched; Branch tips spiny.

Leaves: Compound (odd-1-pinnate), gray-green. Leaflets 3–25 mm, long and narrow.

Flowers: Typical pea-family type flower. Violet-blue flowers stretched out (raceme) over about 5 inches at the end of a stem. Intense color. Petal lobes unequal, upper pair largest.

Seeds: Fruit is a small bean pod with a sharp point. One bean per pod. Fruit glands green, arranged in longitudinal lines.

Habitat: Dry, well-drained sandy, gravelly, and rocky soils in washes, bajadas, and moderate slopes in the lower mountains. Seems to do well with a thin layer of soil overlying caliche.

Elevation: 1,000 to 4,000 feet.

Distribution: Southwestern US.

Comments: Native Americans used the vivid-purple flowers as a dye.