Trifolium dubium
Little hop clover, Little Hop Clover
(c) Douglas Goldman, some rights reserved (CC BY-SA), uploaded by Douglas Goldman · licence
Family: Fabaceae · Type: Herb · Not Native
Trifolium dubium (Little hop clover) is a non-native California herb in the Fabaceae family, recognized by small yellow flowers turning brown diagnostic.
Little hop clover is a naturalized annual found in the California Floristic Province in agricultural and disturbed areas at elevations below 500 meters. Flowering from April to July, this plant produces bright yellow flowers that turn brown with age, clustered in compact heads 4 to 8 millimeters wide. Growing with decumbent to erect stems that are sparsely puberulent, it reaches modest heights with delicate branching. Its leaves have three obovate leaflets 6 to 12 millimeters long, with ovate stipules characteristic of the clover family. The flowers quickly bend downward after blooming, creating a distinctive drooping appearance in disturbed landscapes.
Identification and appearance
Key characters: 68 sympatric species; small yellow flowers turning brown diagnostic
Habitat and range
Habitat: Agricultural, disturbed areas
Elevation: < 500 m
California counties: Humboldt, Placer, Los Angeles, Mariposa, Monterey, Santa Clara, Sacramento, Tuolumne, El Dorado, Santa Barbara, Butte, Mendocino, Siskiyou, Del Norte, Marin, San Diego, Nevada, San Francisco, Sonoma, Contra Costa, Alameda, San Mateo, Fresno, Calaveras, San Luis Obispo, Amador, Yuba, Solano, Napa, Trinity, Shasta, Plumas, Tehama, Glenn, Lake, Sierra, Madera, Modoc, Santa Cruz, Ventura, Stanislaus, Yolo, Colusa, Tulare, Sutter, Inyo
Outside California: much of United States, native to Europe
Bloom period
Trifolium dubium blooms Apr-Jul.
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 dubium native to California?
No. Trifolium dubium is not native to California (recorded as not native).
When does Trifolium dubium bloom?
Trifolium dubium blooms Apr-Jul.
Where in California does Trifolium dubium grow?
Trifolium dubium occurs in Humboldt, Placer, Los Angeles, Mariposa, Monterey, Santa Clara, Sacramento, Tuolumne and other counties, at elevations of < 500 m.
What plant family does Trifolium dubium belong to?
Trifolium dubium is in the Fabaceae family, genus Trifolium.
What habitat does Trifolium dubium grow in?
Trifolium dubium grows in Agricultural, disturbed areas.
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.