Erigeron annuus
Annual fleabane
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Family: Asteraceae · Type: Herb · Not Native
Erigeron annuus (Annual fleabane) is a non-native California herb in the Asteraceae family, recognized by distinctive as non-native annual with numerous tiny rays and no ray pappus.
Annual fleabane is a naturalized annual found in the northern Sierra Nevada and Klamath Ranges in disturbed places at elevations below 2,000 meters. Flowering from April to July, this plant produces white ray flowers up to 8 millimeters long with numerous flower heads 5 to 12 millimeters in diameter. Growing 50 to 120 centimeters tall with often branched stems that are sparsely hairy, it develops from fibrous roots. Its leaves range from basal elliptic to obovate blades 4 to 16 centimeters long, coarsely serrated and becoming slightly reduced toward the stem's upper portion. The plant features inflorescences with 5 to 50 flower heads, each with phyllaries that are spreading-hairy and sparsely glandular.
Identification and appearance
Key characters: 29 sympatric species; distinctive as non-native annual with numerous tiny rays and no ray pappus
Habitat and range
Habitat: Disturbed places
Elevation: < 2000 m
Outside California: native to eastern United States, worldwide weed
Bloom period
Erigeron annuus blooms Apr-Jul.
How to tell it apart
vs Bellis: Erigeron has double-layered pappus (outer scales + inner bristles); Bellis completely lacks pappus.; vs Symphyotrichum: Erigeron has double pappus (2 layers); Symphyotrichum has single layer of uniform bristles.; vs Corethrogyne: Erigeron has simple unbranched stems; Corethrogyne has branched stems.; vs Pseudognaphalium: Erigeron has flat button-like flower heads; Pseudognaphalium has woolly clustered heads without rays.; vs Artemisia: Erigeron has obvious ray petals around yellow disk; Artemisia lacks ray petals entirely.
Frequently asked questions
Is Erigeron annuus native to California?
No. Erigeron annuus is not native to California (recorded as not native).
When does Erigeron annuus bloom?
Erigeron annuus blooms Apr-Jul.
What plant family does Erigeron annuus belong to?
Erigeron annuus is in the Asteraceae family, genus Erigeron.
What habitat does Erigeron annuus grow in?
Erigeron annuus grows in Disturbed places.
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.