Trifolium amoenum
Two-fork clover, Two-Fork Clover
Bloom Valary, U.S. Fish and Wildlife Service (via Wikimedia Commons) · CC0
Family: Fabaceae · Type: Herb · Native
Conservation status: CNPS 1B.1 · Endangered
Trifolium amoenum (Two-fork clover) is a native California herb in the Fabaceae family, recognized by large bicolor flowers and robust habit diagnostic.
Two-fork clover is a rare (CNPS 1B.1) California native annual found in southern North Coast Ranges, northern Central Coast, and San Francisco Bay Area in moist, heavy soils and disturbed areas at elevations below 100 meters. Flowering from April to June, this plant produces distinctive purple flowers with white tips in ovate to spheric heads. Growing 10 to 30 centimeters tall with erect, generally robust and hairy stems, it displays a sturdy upright form. Its leaves have three widely obovate leaflets with conspicuous stipules, creating a delicate yet structured appearance. The plant produces 1 to 2 seeds and is characterized by its slender, plumose calyx lobes that extend beyond the flower tube.
Identification and appearance
Key characters: 47 sympatric species; large bicolor flowers and robust habit diagnostic
Habitat and range
Habitat: Moist, heavy soils, disturbed areas
Elevation: < 100 m
California counties: Sonoma, San Mateo, Solano, Marin, Napa
Bloom period
Trifolium amoenum blooms Apr-Jun.
Conservation status
CNPS 1B.1 · Endangered
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 amoenum native to California?
Yes. Trifolium amoenum is native to California (recorded as native).
When does Trifolium amoenum bloom?
Trifolium amoenum blooms Apr-Jun.
Where in California does Trifolium amoenum grow?
Trifolium amoenum occurs in Sonoma, San Mateo, Solano, Marin, Napa, at elevations of < 100 m.
What plant family does Trifolium amoenum belong to?
Trifolium amoenum is in the Fabaceae family, genus Trifolium.
Is Trifolium amoenum rare or endangered?
Trifolium amoenum carries California Rare Plant Rank 1B.1, state rank S1.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CNPS Rare Plant Inventory · Index of California Plant Names · CalPhotos · CDFW CNDDB
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.