Cotula coronopifolia
Brass-buttons
Photo by Chez Brungraber
Family: Asteraceae · Type: Herb · Not Native
Conservation status: Cal-IPC Yes
Cotula coronopifolia (Brass-buttons) is a non-native California herb in the Asteraceae family, recognized by key differences are habitat, bright yellow flowers, and sheathing leaf bases.
Brass-buttons is a naturalized perennial found in coastal and central California regions including northern Coast Ranges, Sacramento Valley, central Western California, southern California Coast, Channel Islands, and Peninsular Ranges in saline and freshwater marshes and mud flats at elevations below 1,200 meters. Flowering from March to December, this plant produces bright yellow disk flowers in small compact heads. Growing with prostrate or erect stems 5 to 40 centimeters tall that root at the nodes, it spreads readily across wet habitats. Its linear to lanceolate leaves are 2 to 7 centimeters long, fused at the base to form a sheath around the stem and covered with resin glands. The fruit is prominently stalked and winged, with outer segments 1.2 to 2 millimeters long.
Identification and appearance
Key characters: 1 sympatric species; key differences are habitat, bright yellow flowers, and sheathing leaf bases
Habitat and range
Habitat: Common. Saline and freshwater marshes, mud flats
Elevation: < 1200 m
Outside California: native to southern Africa
Bloom period
Cotula coronopifolia blooms Mar-Dec.
Conservation status
Cal-IPC Yes
How to tell it apart
vs Lepidium: Lepidium has four-petaled flowers and flat seed pods; Cotula has buttonlike composite heads.; vs Matricaria: Matricaria has white ray flowers around the disk; Cotula lacks ray flowers entirely.; vs Soliva: Soliva flower heads sit directly on stem hidden by leaves; Cotula heads elevated on leafless stalks.; vs Oncosiphon: Oncosiphon has feathery divided leaves; Cotula has less finely divided, broader leaf segments.; vs Helenium: Helenium is tall with wedge-shaped ray flowers; Cotula is prostrate with no rays.
Frequently asked questions
Is Cotula coronopifolia native to California?
No. Cotula coronopifolia is not native to California (recorded as not native).
When does Cotula coronopifolia bloom?
Cotula coronopifolia blooms Mar-Dec.
What plant family does Cotula coronopifolia belong to?
Cotula coronopifolia is in the Asteraceae family, genus Cotula.
Is Cotula coronopifolia invasive in California?
Cotula coronopifolia is listed by Cal-IPC with an invasiveness rating of Yes.
What habitat does Cotula coronopifolia grow in?
Cotula coronopifolia grows in Common. Saline and freshwater marshes, mud flats.
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.