Grindelia squarrosa var. serrulata
Curlycup gumweed
Stan Shebs (via Wikimedia Commons) · CC BY-SA
Family: Asteraceae · Type: Herb · Not Native
Grindelia squarrosa var. serrulata (Curlycup gumweed) is a non-native California herb in the Asteraceae family, recognized by biennial habit, leaf teeth with yellow bumps, and coiled phyllaries.
Curlycup gumweed is a naturalized biennial found in California's High Sierra Nevada, Transverse Ranges, Great Basin, and Mojave Desert in disturbed roadsides and streamsides at elevations of 700 to 2,300 meters. Flowering from July to September, this plant produces yellow flowers with distinctive green-tipped, straw-colored phyllaries that curl completely around in a 360-degree coil. Growing up to 60 centimeters tall with a much-branched structure, it develops decumbent to erect stems that spread extensively across disturbed areas. Its leaves are gray-green, oblong to ovate, with crenate edges featuring small yellow bumps at each tooth's tip, creating a unique textural appearance. The fruit is light brown to yellowish, topped with 2 to 3 short pappus awns that aid in seed dispersal.
Identification and appearance
Key characters: 5 sympatric species; distinguished by biennial habit, leaf teeth with yellow bumps, and coiled phyllaries
Habitat and range
Habitat: Disturbed roadsides, streamsides
Elevation: 700-2300 m
Outside California: native Wyoming to New Mexico
Bloom period
Grindelia squarrosa var. serrulata blooms Jul-Sep.
How to tell it apart
vs Heterotheca: Grindelia has sticky gummy bracts; Heterotheca has dry, non-sticky bracts and spreading hairs on stems.; vs Agoseris: Grindelia has ray and disc flowers; Agoseris has only strap-shaped ligulate flowers (dandelion-like).; vs Erigeron: Grindelia has gummy sticky bracts; Erigeron has dry bracts and typically 50+ very narrow rays.; vs Solidago: Grindelia has large sticky-bracted heads; Solidago has tiny non-sticky heads in dense branched clusters.; vs Deinandra: Grindelia bracts curl backward and are gummy; Deinandra has spine-tipped bracts and is a tarweed.
Frequently asked questions
Is Grindelia squarrosa var. serrulata native to California?
No. Grindelia squarrosa var. serrulata is not native to California (recorded as not native).
When does Grindelia squarrosa var. serrulata bloom?
Grindelia squarrosa var. serrulata blooms Jul-Sep.
What plant family does Grindelia squarrosa var. serrulata belong to?
Grindelia squarrosa var. serrulata is in the Asteraceae family, genus Grindelia.
What habitat does Grindelia squarrosa var. serrulata grow in?
Grindelia squarrosa var. serrulata grows in Disturbed roadsides, streamsides.
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.