Trifolium wormskioldii
Cow clover
(c) Ken-ichi Ueda, some rights reserved (CC BY), uploaded by Ken-ichi Ueda · licence
Family: Fabaceae · Type: Herb · Native
Trifolium wormskioldii (Cow clover) is a native California herb in the Fabaceae family, recognized by perennial habit, large flowers, and wheel-shaped involucre.
Cow clover is a California native perennial found in northwestern California, Cascade Range, Sierra Nevada, San Joaquin Valley, central and southern coastal California, Peninsular Ranges, and eastern Sierra Nevada in beaches, mountain meadows, and open moist places at elevations up to 3,200 meters. Flowering from May to October, this plant produces pink-purple to magenta flowers with white tips in dense 2 to 3 centimeter wide heads. Growing with decumbent or ascending stems that form clumps or spread via rhizomes, it reaches moderate heights with a clustered growth habit. Its leaves typically feature 1 to 3 centimeter leaflets ranging from narrowly elliptic to widely ovate, with lower leaf stipules ending in bristle-like tips. The plant's distinctive flower heads have many wheel-shaped segments with calyx lobes that taper to bristled tips.
Identification and appearance
Key characters: 66 sympatric species - distinguished by perennial habit, large flowers, and wheel-shaped involucre
Habitat and range
Habitat: Beaches to mountain meadows, ridges, generally open moist or marshy places
Elevation: < 3200 m
California counties: Humboldt, Placer, San Luis Obispo, San Diego, San Bernardino, Plumas, Kern, Riverside, Mono, Inyo, Los Angeles, Tulare, Butte, Santa Barbara, Lassen, Monterey, Del Norte, Sonoma, Siskiyou, Mendocino, Nevada, San Mateo, Madera, Fresno, Santa Cruz, Lake, Marin, Tuolumne, Sutter, Ventura, Modoc, Santa Clara, San Benito, Amador, San Francisco, Orange, Trinity, Sierra, Tehama, Alpine, Calaveras, Yuba, Contra Costa, Shasta, Glenn, Colusa, Napa, Alameda, Mariposa, El Dorado, Solano, Sacramento
Outside California: to British Columbia, Wyoming, New Mexico, Mexico
Bloom period
Trifolium wormskioldii blooms May-Oct.
How to tell it apart
vs Medicago: Trifolium flowers persist around fruits; Medicago flowers fall off leaving exposed coiled fruits.; vs Oxalis: Trifolium has pea-shaped flowers; wood-sorrels (Oxalis) have 5-petaled star-shaped flowers and heart-notched leaflets.; vs Melilotus: Trifolium flowers persist enclosing fruits; Melilotus flowers fall off leaving exposed ridged pods.; vs Castilleja: Trifolium has pea flowers and 3 toothed leaflets; paintbrush (Castilleja) has tubular flowers in colorful bracts.; vs Acmispon: Trifolium leaflets have toothed edges; Acmispon leaflets have smooth untoothed margins.
Frequently asked questions
Is Trifolium wormskioldii native to California?
Yes. Trifolium wormskioldii is native to California (recorded as native).
When does Trifolium wormskioldii bloom?
Trifolium wormskioldii blooms May-Oct.
Where in California does Trifolium wormskioldii grow?
Trifolium wormskioldii occurs in Humboldt, Placer, San Luis Obispo, San Diego, San Bernardino, Plumas, Kern, Riverside and other counties, at elevations of < 3200 m.
What plant family does Trifolium wormskioldii belong to?
Trifolium wormskioldii is in the Fabaceae family, genus Trifolium.
What habitat does Trifolium wormskioldii grow in?
Trifolium wormskioldii grows in Beaches to mountain meadows, ridges, generally open moist or marshy places.
Related species
Other California species in the same genus, family, or bioregion.
- Trifolium albopurpureum — Indian clover
- Trifolium alexandrinum — Egyptian clover
- Trifolium amoenum — Two-fork clover
- Trifolium andersonii — Anderson's clover
- Trifolium andersonii subsp. andersonii — Anderson's clover
- Trifolium andersonii subsp. beatleyae — Beatley's five-leaved clover
- Ulex europaeus — Common gorse
- Ulex sp. — Gorse
- Vachellia farnesiana — Sweet acacia
- Vachellia farnesiana var. farnesiana — Sweet acacia
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.