Trifolium microdon
Thimble clover
(c) Ken-ichi Ueda, some rights reserved (CC BY), uploaded by Ken-ichi Ueda · licence
Family: Fabaceae · Type: Herb · Native
Trifolium microdon (Thimble clover) is a native California herb in the Fabaceae family, recognized by . Key feature: cup-shaped involucre with bristle tips.
Thimble clover is a California native annual herb found in coastal and inland regions including northern California Coast Ranges, northern Sierra Nevada foothills, Central Valley, Central Western California, Channel Islands, and Peninsular Ranges at elevations of 10 to 1,100 meters in open, moist or disturbed areas. Flowering from March to June, this plant produces white to pink flowers in compact heads 7 to 14 millimeters wide with bristle-tipped involucre divisions. Growing with decumbent to erect puberulent stems, it forms low-spreading or upright plants. Its leaves have three leaflets 5 to 15 millimeters long, oblanceolate to obovate with truncate or notched tips, positioned with wide stipules along the stem. Each flower cluster contains 5 to many small blossoms with a delicate, cup-shaped calyx.
Identification and appearance
Key characters: 53 sympatric species. Key feature: cup-shaped involucre with bristle tips
Habitat and range
Habitat: Common locally. Open, moist or dry, generally disturbed areas
Elevation: 10-1100 m
California counties: Los Angeles, Ventura, Sonoma, Santa Barbara, Lake, Sacramento, Mendocino, San Francisco, Alameda, Marin, Napa, Del Norte, Humboldt, Solano, San Mateo, Contra Costa, Santa Cruz, Santa Clara, San Joaquin, Nevada, Tehama, Shasta, Butte, Monterey, Calaveras, Stanislaus, Trinity, San Luis Obispo, Mariposa, El Dorado, Tuolumne, Merced, Colusa, Plumas
Outside California: to British Columbia, South America
Bloom period
Trifolium microdon blooms Mar-Jun.
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 microdon native to California?
Yes. Trifolium microdon is native to California (recorded as native).
When does Trifolium microdon bloom?
Trifolium microdon blooms Mar-Jun.
Where in California does Trifolium microdon grow?
Trifolium microdon occurs in Los Angeles, Ventura, Sonoma, Santa Barbara, Lake, Sacramento, Mendocino, San Francisco and other counties, at elevations of 10-1100 m.
What plant family does Trifolium microdon belong to?
Trifolium microdon is in the Fabaceae family, genus Trifolium.
What habitat does Trifolium microdon grow in?
Trifolium microdon grows in Common locally. Open, moist or dry, generally disturbed areas.
Related species
Other California species in the same genus, family, or bioregion.
- Trifolium monanthum — Carpet clover
- Trifolium monanthum subsp. grantianum — Grant's carpet clover
- Trifolium monanthum subsp. monanthum — Carpet clover
- Trifolium monanthum subsp. parvum — Small carpet clover
- Trifolium monanthum subsp. tenerum — Delicate carpet clover
- Trifolium obtusiflorum — Clammy clover
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.