Tetradymia axillaris var. axillaris
Catclaw horsebrush
Photo: parent species Tetradymia axillaris · (c) Andrew Conboy, some rights reserved (CC BY) · licence
Family: Asteraceae · Type: Shrub · Native
Tetradymia axillaris var. axillaris (Catclaw horsebrush) is a native California shrub in the Asteraceae family, recognized by key difference is glabrous vs tomentose peduncle/involucre and hair length.
Catclaw horsebrush is a California native shrub found in the northern Desert Mountains and White and Inyo Mountains in desert scrub and woodland habitats at elevations of 1,150 to 2,300 meters. Flowering from April to May, this plant produces yellow flowers in heads with glabrous peduncles and involucres. Growing with branching stems that form dense, rounded shapes, it develops a sturdy woody structure typical of desert shrubs. Its leaves are small and narrow, clustered along the branches and contributing to the plant's compact form. The fruit is notable for having soft, elongated hairs measuring 6 to 8 millimeters long.
Identification and appearance
Key characters: 5 sympatric species; key difference is glabrous vs tomentose peduncle/involucre and hair length
Habitat and range
Habitat: Desert scrub, woodland
Elevation: 1150-2300 m
California counties: Inyo, Kern, Riverside, Los Angeles
Outside California: southern Nevada
Bloom period
Tetradymia axillaris var. axillaris blooms Apr-May.
How to tell it apart
vs Ericameria: Tetradymia has 4-6 bracts in 1-2 rows; Ericameria has many bracts in 5 vertical rows.; vs Artemisia: Tetradymia has rigid spine-tipped branches; Artemisia has soft, non-spiny aromatic foliage.; vs Lycium: Tetradymia has yellow composite flowers; Lycium has tubular purple/greenish flowers with 5 petals.; vs Senecio: Tetradymia has 4-8 flowers per head with woolly appearance; Senecio has more flowers per head and often ray petals.; vs Krascheninnikovia: Tetradymia has yellow composite flowers; Krascheninnikovia has tiny greenish flowers without petals (Chenopodiaceae family).
Frequently asked questions
Is Tetradymia axillaris var. axillaris native to California?
Yes. Tetradymia axillaris var. axillaris is native to California (recorded as native).
When does Tetradymia axillaris var. axillaris bloom?
Tetradymia axillaris var. axillaris blooms Apr-May.
Where in California does Tetradymia axillaris var. axillaris grow?
Tetradymia axillaris var. axillaris occurs in Inyo, Kern, Riverside, Los Angeles, at elevations of 1150-2300 m.
What plant family does Tetradymia axillaris var. axillaris belong to?
Tetradymia axillaris var. axillaris is in the Asteraceae family, genus Tetradymia.
What habitat does Tetradymia axillaris var. axillaris grow in?
Tetradymia axillaris var. axillaris grows in Desert scrub, woodland.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.