Ranunculus occidentalis
Western buttercup
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Family: Ranunculaceae · Type: Herb · Native
Ranunculus occidentalis (Western buttercup) is a native California herb in the Ranunculaceae family.
Western buttercup is a California native perennial found in various bioregions in grasslands, meadows, and open woodlands at elevations from low to moderate ranges. Flowering from March to June, this plant produces bright yellow flowers with distinctive cup-shaped petals that create a glossy, golden appearance. Growing with multiple delicate stems 10 to 60 centimeters tall, it forms a loose, spreading habit with multiple branches. Its distinctive leaves are widely ovate to semicircular, typically basal and proximal, ranging 1.5 to 5.3 centimeters long with deeply divided or compound upper stem leaves. The fruit develops as a compact, disk-like structure with a thick, smooth wall characteristic of buttercup species.
Identification and appearance
Key characters: Geographically isolated with 0 sympatric species
Habitat and range
California counties: Humboldt, Mendocino, Placer, Amador, Lake, Lassen, Tulare, Plumas, Fresno, Contra Costa, El Dorado, Tehama, Shasta, Siskiyou, Modoc, Kern, Del Norte, Trinity, Tuolumne, Riverside, Sierra, Calaveras, Sonoma, Nevada, Napa, Yuba, Butte, Solano, Sutter, Glenn, Mariposa, Alpine, Inyo, Madera, Mono, Marin, Colusa, San Joaquin, San Luis Obispo, Alameda, Yolo, Stanislaus
How to tell it apart
vs Lasthenia: Ranunculus has separate petals around a central disk; Lasthenia has many tiny ray flowers around a disk (composite head).; vs Bowlesia: Ranunculus has glossy yellow petals in conspicuous flowers; Bowlesia has tiny white flowers in umbels with divided leaves.; vs Potentilla: Ranunculus has nectaries at petal bases and many pistils; Potentilla has no nectaries and styles attached to ovary sides.; vs Papaver: Ranunculus has 5 petals and many pistils; Papaver has 4 crinkled petals and a single large stigma disk.; vs Oxalis: Ranunculus has glossy separate petals; Oxalis has clover-like leaves and tubular flowers that close at night.
Frequently asked questions
Is Ranunculus occidentalis native to California?
Yes. Ranunculus occidentalis is native to California (recorded as native).
Where in California does Ranunculus occidentalis grow?
Ranunculus occidentalis occurs in Humboldt, Mendocino, Placer, Amador, Lake, Lassen, Tulare, Plumas and other counties.
What plant family does Ranunculus occidentalis belong to?
Ranunculus occidentalis is in the Ranunculaceae family, genus Ranunculus.
Related species
Other California species in the same genus, family, or bioregion.
- Ranunculus occidentalis var. dissectus — Western buttercup
- Ranunculus occidentalis var. howellii — Western buttercup
- Ranunculus occidentalis var. occidentalis — Western buttercup
- Ranunculus occidentalis var. ultramontanus — Western buttercup
- Ranunculus orthorhynchus — Bloomer's buttercup
- Ranunculus orthorhynchus var. bloomeri — Bloomer's beaked buttercup
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.