Trifolium striatum
Knotted clover
(c) Brenda Black, some rights reserved (CC BY) · licence
Family: Fabaceae · Type: Herb · Not Native
Trifolium striatum (Knotted clover) is a non-native California herb in the Fabaceae family, recognized by . Key features: sessile cylindric heads, 10-nerved sepals.
Knotted clover is a naturalized annual found in northern California regions including the North Coast Ranges Interior, Cascade Range Foothills, northern Sierra Nevada Foothills, Central Coast, and southern Coast Ranges in disturbed areas at elevations from sea level to 685 meters. Flowering from May to June, this plant produces pink flowers in dense, short-cylindric heads about 0.5 to 1.5 centimeters long. Growing with decumbent, ascending, or erect hairy stems, it has a delicate, spreading habit. Its leaves have three leaflets 6 to 16 millimeters long, ranging from obovate-oblong to oblanceolate, with ovate stipules that have triangular-linear tips. The flower's banner is distinctively notched at the tip, with calyx lobes sparsely covered in soft hairs.
Identification and appearance
Key characters: 54 sympatric species. Key features: sessile cylindric heads, 10-nerved sepals
Habitat and range
Habitat: Disturbed areas
Elevation: 0-685 m
California counties: Shasta, Nevada, Marin, Sonoma, Napa, Monterey, Yuba, Solano, Mendocino, San Luis Obispo, Santa Cruz, Yolo, Placer
Outside California: United States, native to Europe, northern Africa
Bloom period
Trifolium striatum blooms May-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 striatum native to California?
No. Trifolium striatum is not native to California (recorded as not native).
When does Trifolium striatum bloom?
Trifolium striatum blooms May-Jun.
Where in California does Trifolium striatum grow?
Trifolium striatum occurs in Shasta, Nevada, Marin, Sonoma, Napa, Monterey, Yuba, Solano and other counties, at elevations of 0-685 m.
What plant family does Trifolium striatum belong to?
Trifolium striatum is in the Fabaceae family, genus Trifolium.
What habitat does Trifolium striatum grow in?
Trifolium striatum grows in 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.