Trifolium trichocalyx
Monterey clover
Ronald Branson (via Wikimedia Commons) · CC0
Family: Fabaceae · Type: Herb · Native
Conservation status: CNPS 1B.1 · Endangered
Trifolium trichocalyx (Monterey clover) is a native California herb in the Fabaceae family, recognized by . Key features: Monterey Peninsula + Mendocino, hairy sepals.
Monterey clover is a rare (CNPS 1B.1) California native annual found in western central North Coast Ranges in Mendocino County and on the Monterey Peninsula in open closed-cone pine woodland and roadsides at elevations below 100 meters. Flowering from April to June, this plant produces pink to lavender flowers in compact heads 4 to 14 millimeters wide. Growing with spreading stems and a sparse hairiness that becomes nearly smooth with age, it develops delicate branching structures. Its leaves have three leaflets, each 5 to 10 millimeters long, ranging from oblanceolate to obovate with toothed or lobed stipules. The plant's calyx is notably hairy, with lobes longer than the tube and featuring distinctive bristle-tipped ends.
Identification and appearance
Key characters: 27 sympatric species. Key features: Monterey Peninsula + Mendocino, hairy sepals
Habitat and range
Habitat: Open closed-cone pine woodland, roadsides
Elevation: < 100 m
Bloom period
Trifolium trichocalyx 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 trichocalyx native to California?
Yes. Trifolium trichocalyx is native to California (recorded as native).
When does Trifolium trichocalyx bloom?
Trifolium trichocalyx blooms Apr-Jun.
What plant family does Trifolium trichocalyx belong to?
Trifolium trichocalyx is in the Fabaceae family, genus Trifolium.
Is Trifolium trichocalyx rare or endangered?
Trifolium trichocalyx carries California Rare Plant Rank 1B.1, state rank S1.
What habitat does Trifolium trichocalyx grow in?
Trifolium trichocalyx grows in Open closed-cone pine woodland, roadsides.
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.