Psorothamnus arborescens var. californicus
California indigo bush
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Family: Fabaceae · Type: Shrub · Native
Psorothamnus arborescens var. californicus (California indigo bush) is a native California shrub in the Fabaceae family, recognized by narrow leaflets and silky hairs are key.
California indigo bush is a California native shrub found in southern desert mountains and adjacent desert regions on lower mountain slopes, flats, and washes at elevations of 100 to 1,100 meters. Flowering from April to May, this plant produces small, delicate flowers with silky-textured foliage. Growing as a spreading shrub 1 to 2 meters tall with multiple branching stems, it has a distinctive desert mountain form. Its leaves are composed of narrow, linear-oblanceolate leaflets about 1 to 2 millimeters wide, covered in silky fine hairs that give the plant a soft, silvery appearance. The shrub's calyx is 5 to 7 millimeters long and lightly covered with fine hairs, contributing to its delicate desert adaptation.
Identification and appearance
Key characters: 1 sympatric species; narrow leaflets and silky hairs are key
Habitat and range
Habitat: Lower desert mountain slopes, flats, washes
Elevation: 100-1100 m
Bloom period
Psorothamnus arborescens var. californicus blooms Apr-May.
How to tell it apart
vs Psorodendron: Psorothamnus has gland-dotted surfaces and indigo-purple flowers; Psorodendron has smooth surfaces and yellow flowers.; vs Astragalus: Psorothamnus has gland-dotted surfaces and single-seeded pods; Astragalus has smooth surfaces and multi-seeded inflated pods.; vs Dalea: Psorothamnus has petals arising from flower base; Dalea has petals arising from a fused stamen column.; vs Condea: Psorothamnus has pea-shaped flowers; Condea has two-lipped tubular flowers (mint family).; vs Scutellaria: Psorothamnus has pea-shaped flowers; Scutellaria has hooded two-lipped flowers (mint family).
Frequently asked questions
Is Psorothamnus arborescens var. californicus native to California?
Yes. Psorothamnus arborescens var. californicus is native to California (recorded as native).
When does Psorothamnus arborescens var. californicus bloom?
Psorothamnus arborescens var. californicus blooms Apr-May.
What plant family does Psorothamnus arborescens var. californicus belong to?
Psorothamnus arborescens var. californicus is in the Fabaceae family, genus Psorothamnus.
What habitat does Psorothamnus arborescens var. californicus grow in?
Psorothamnus arborescens var. californicus grows in Lower desert mountain slopes, flats, washes.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CalPhotos
Last updated 2026-10-06
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.