Bidens laevis
Bur-marigold
(c) Michael D Fox, some rights reserved (CC BY), uploaded by Michael D Fox · licence
Family: Asteraceae · Type: Herb · Native
Bidens laevis (Bur-marigold) is a native California herb in the Asteraceae family, recognized by . Key features are large size, simple leaves, large ray flowers, and perennial habit.
Bur-marigold is a California native perennial found in the Great Valley, Central Western, Southwestern, Southeastern Sierra Nevada, and Mojave River regions in freshwater wetlands at elevations below 2,000 meters. Flowering from August to November, this plant produces bright yellow ray flowers up to 3 centimeters long surrounding a yellow disk, creating distinctive daisy-like flower heads. Growing 2 to 2.5 meters tall with somewhat decumbent to erect cylindrical stems, it develops lance-shaped leaves that can be 5 to 15 centimeters long with serrated edges. Its leaves are simple and sessile, sometimes fusing at the base around the stem, creating a distinctive architectural pattern. The fruit develops as a narrow wedge-shaped structure with thin, barbed angles that help in seed dispersal.
Identification and appearance
Key characters: 5 sympatric species. Key features are large size, simple leaves, large ray flowers, and perennial habit.
Habitat and range
Habitat: Freshwater wetlands
Elevation: < 2000 m
Outside California: to eastern North America
Bloom period
Bidens laevis blooms Aug-Nov.
How to tell it apart
vs Tagetes: Tagetes has strongly scented gland-dotted leaves; Bidens lacks strong scent and glands.; vs Dahlia: Dahlia has showy ray flowers and tuberous roots; Bidens often lacks rays and has fibrous roots.; vs Arnica: Arnica has opposite leaves throughout and mountain habitat; Bidens has mostly alternate leaves in wetlands.; vs Cosmos: Cosmos has finely dissected feathery leaves; Bidens has broader, less divided leaves.; vs Helianthus: Helianthus has rough sandpapery leaves and unbarbed pappus; Bidens has barbed stick-tight seeds.
Frequently asked questions
Is Bidens laevis native to California?
Yes. Bidens laevis is native to California (recorded as native).
When does Bidens laevis bloom?
Bidens laevis blooms Aug-Nov.
What plant family does Bidens laevis belong to?
Bidens laevis is in the Asteraceae family, genus Bidens.
What habitat does Bidens laevis grow in?
Bidens laevis grows in Freshwater wetlands.
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.