Trifolium glomeratum
Clustered clover
(c) zebedeugalinha, some rights reserved (CC BY) · licence
Family: Fabaceae · Type: Herb · Not Native
Trifolium glomeratum (Clustered clover) is a non-native California herb in the Fabaceae family, recognized by sessile heads and 10-ribbed calyx are key features.
Clustered clover is a naturalized annual found in the California Floristic Province in disturbed areas at elevations below 300 meters. Flowering from March to May, this plant produces pink flowers in dense, compact heads 7 to 10 millimeters wide. Growing with decumbent to ascending stems that are nearly hairless, it reaches a low-spreading habit. Its leaves have three leaflets, each 5 to 12 millimeters long and obovate in shape, with stipules that have short bristle-like tips. The flower calyx is 3 to 5 millimeters long with ten ribs and triangular lobes that recurve when the fruit develops.
Identification and appearance
Key characters: 68 sympatric species; sessile heads and 10-ribbed calyx are key features
Habitat and range
Habitat: Uncommon. Disturbed areas
Elevation: < 300 m
California counties: Calaveras, Butte, Mendocino, Yuba, El Dorado, Amador, Napa, Tehama, San Luis Obispo, Tulare, Santa Cruz, Nevada, Placer, Marin, Solano, Contra Costa, Humboldt, Shasta, Glenn, Madera, Alameda, San Mateo, Sonoma, Yolo, Sacramento, Colusa, Siskiyou, Lake, Imperial, Monterey, San Diego
Outside California: United States, native to Europe, Africa
Bloom period
Trifolium glomeratum blooms Mar-May.
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 glomeratum native to California?
No. Trifolium glomeratum is not native to California (recorded as not native).
When does Trifolium glomeratum bloom?
Trifolium glomeratum blooms Mar-May.
Where in California does Trifolium glomeratum grow?
Trifolium glomeratum occurs in Calaveras, Butte, Mendocino, Yuba, El Dorado, Amador, Napa, Tehama and other counties, at elevations of < 300 m.
What plant family does Trifolium glomeratum belong to?
Trifolium glomeratum is in the Fabaceae family, genus Trifolium.
What habitat does Trifolium glomeratum grow in?
Trifolium glomeratum grows in Uncommon. 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.