Ranunculus arvensis
Corn buttercup
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Family: Ranunculaceae · Type: Herb · Not Native
Ranunculus arvensis (Corn buttercup) is a non-native California herb in the Ranunculaceae family, recognized by spiny fruits diagnostic, non-native annual.
Corn buttercup is a naturalized annual herb found in northern California bioregions including Klamath Ranges, North Coast Ranges Interior, Cascade Range, northern Sierra Nevada Foothills, Sacramento Valley, and Modoc Plateau in roadsides, fields, and disturbed areas at elevations below 1,000 meters. Flowering from April to May, this plant produces yellow flowers with five petals 5 to 8 millimeters long. Growing 10 to 40 centimeters tall with erect or ascending stems, it develops from an annual or biennial habit. Its distinctive leaves are deeply lobed or dissected, with obovate to wedge-shaped basal and lower cauline leaves featuring oblanceolate leaflets divided into entire or distally dentate segments. The fruit develops a disk-like body with spiny walls and a straight lanceolate beak 1.6 to 3.8 millimeters long.
Identification and appearance
Key characters: 51 sympatric species; spiny fruits diagnostic, non-native annual
Habitat and range
Habitat: Roadsides, fields, disturbed areas
Elevation: < 1000 m
California counties: Mendocino, Butte, San Luis Obispo, El Dorado, Orange, Lake, Colusa, Del Norte, Sacramento, Nevada, Yuba, Sonoma, Siskiyou, Tehama, Shasta, Modoc, Lassen, Napa, Santa Cruz, Humboldt, Solano, Trinity, Mariposa, Alameda, Tuolumne
Outside California: to Washington, New York, South America, Australia, native to Eurasia
Bloom period
Ranunculus arvensis blooms Apr-May.
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 arvensis native to California?
No. Ranunculus arvensis is not native to California (recorded as not native).
When does Ranunculus arvensis bloom?
Ranunculus arvensis blooms Apr-May.
Where in California does Ranunculus arvensis grow?
Ranunculus arvensis occurs in Mendocino, Butte, San Luis Obispo, El Dorado, Orange, Lake, Colusa, Del Norte and other counties, at elevations of < 1000 m.
What plant family does Ranunculus arvensis belong to?
Ranunculus arvensis is in the Ranunculaceae family, genus Ranunculus.
What habitat does Ranunculus arvensis grow in?
Ranunculus arvensis grows in Roadsides, fields, disturbed areas.
Related species
Other California species in the same genus, family, or bioregion.
- Ranunculus bonariensis var. trisepalus — Carter's buttercup
- Ranunculus bulbosus — Bulbous buttercup
- Ranunculus californicus — California buttercup
- Ranunculus californicus var. californicus — Common buttercup
- Ranunculus californicus var. cuneatus — Common buttercup
- Ranunculus canus — Great valley 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.