Isocoma arguta
Carquinez goldenbush
(c) Kyle Elshoff, some rights reserved (CC BY) · licence
Family: Asteraceae · Type: Subshrub · Native
Conservation status: CNPS 1B.1
Isocoma arguta (Carquinez goldenbush) is a native California subshrub in the Asteraceae family, recognized by no sympatric species.
Carquinez goldenbush is a rare (CNPS 1B.1) California native shrub found in southern Sacramento Valley in alkaline grassland and low hill habitats at elevations below 20 meters. Flowering from August to December, this plant produces yellow flowers in compact clusters with involucres 4.5 to 7 millimeters wide. Growing to less than 0.5 meters tall with erect to slightly decumbent stems that branch at the base and have a scabrous texture. Its leaves are linear to oblong, light gray-green, less than 2 centimeters long, with serrate or pinnately lobed edges that have minutely awn-tipped teeth. The shrub features scattered stems that can have long hairs, creating a distinctive appearance in its sparse grassland environment.
Identification and appearance
Key characters: Geographically isolated; no sympatric species
Habitat and range
Habitat: Alkaline soils, flats, low hills, grassland
Elevation: < 20 m
Bloom period
Isocoma arguta blooms Aug-Dec.
Conservation status
CNPS 1B.1
How to tell it apart
vs Ericameria: Isocoma has randomly arranged bracts; Ericameria has bracts in 5 distinct vertical rows.; vs Hazardia: Isocoma has smooth or slightly hairy stems; Hazardia has densely hairy stems and leaves.; vs Baccharis: Isocoma has yellow bisexual flowers; Baccharis has whitish flowers on separate male/female plants.; vs Heterotheca: Isocoma has only disk flowers; Heterotheca has showy yellow ray flowers around the disk.; vs Eriogonum: Isocoma has yellow composite flowers; Eriogonum has small clustered flowers with colorful sepals but no petals.
Frequently asked questions
Is Isocoma arguta native to California?
Yes. Isocoma arguta is native to California (recorded as native).
When does Isocoma arguta bloom?
Isocoma arguta blooms Aug-Dec.
What plant family does Isocoma arguta belong to?
Isocoma arguta is in the Asteraceae family, genus Isocoma.
Is Isocoma arguta rare or endangered?
Isocoma arguta carries California Rare Plant Rank 1B.1, state rank S1.
What habitat does Isocoma arguta grow in?
Isocoma arguta grows in Alkaline soils, flats, low hills, grassland.
Related species
Other California species in the same genus, family, or bioregion.
- Isocoma menziesii — Coastal goldenbush
- Isocoma menziesii var. decumbens — Decumbent goldenbush
- Isocoma menziesii var. diabolica — Satan's goldenbush
- Isocoma menziesii var. menziesii — Menzies' goldenbush
- Isocoma menziesii var. sedoides — Menzies' goldenbush
- Isocoma menziesii var. vernonioides — Coastal goldenbush
Sources: Jepson eFlora · CalPhotos · CDFW CNDDB
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.