Psorothamnus arborescens (A. Gray) Barneby var. simplicifolius
(Parish) Barneby

California Indigo Bush
Fabaceae (Pea Family)


California indigo bush is a spinescent, much-branched, hoary-tomentose shrub growing typically 3'-4' tall.  The pinnate leaves are about an inch long with several pairs of oblanceolate leaflets generally continuous with the axis.  The flowers are in an open raceme about 2" long.  There is a puberulent calyx with ± equal lobes, and a deep violet-blue to purple corolla.  The fruit is a pod that is villous, dotted with large glands, and having a beak 1/4" long.  California indigo bush may be found on the lower desert mountains slopes, canyons, flats and washes to about 3000' especially in the southern part of the Mojave Desert of San Bernardino County, blooming from April to May.  There are other variants such as the more uncommon arborescens of the western Mojave and minutifolius which may be found in the northern and central Mojave Desert. These pictures are from Mission Creek Preserve in Morongo Valley. 

Click here for Latin name derivations: 1) Psorothamnus 2) arborescens 3) simplicifolius.
Pronunciation: soar-oh-THAM-nus ar-bore-ES-ens sim-pli-si-FO-lee-us.
Click here for Botanical Term Meanings.