Trifolium longipes subsp. atrorubens
Photo: parent species Trifolium longipes · (c) paulexcoff, some rights reserved (CC BY-SA) · licence
Family: Fabaceae · Type: Herb · Native
Trifolium longipes subsp. atrorubens is a native California herb in the Fabaceae family, recognized by key features: thickened fusiform roots, short-elliptic leaflets, densely hairy calyx.
Dark-colored trifolium is a California native perennial found in northern Coast Ranges, Sierra Nevada, San Bernardino Mountains, and San Jacinto Mountains in dry or boggy meadows, open slopes, woodland, and subalpine areas at elevations of 1,100 to 3,000 meters. Flowering from June to September, this plant produces white to purple flowers with densely long-hairy calyx lobes. Growing with thickened, fusiform roots and short stems, it forms low-spreading clumps in mountain habitats. Its leaves have short-elliptic leaflets approximately 2.5 to 6 times longer than wide, with obtuse tips. The flowers spread or rise slightly above the foliage, creating delicate clusters in alpine and woodland environments.
Identification and appearance
Key characters: 45 sympatric species; key features: thickened fusiform roots, short-elliptic leaflets, densely hairy calyx
Habitat and range
Habitat: dry or boggy meadows, open slopes, woodland, subalpine
Elevation: 1100-3000 m
Bloom period
Trifolium longipes subsp. atrorubens blooms Jun-Sep.
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 longipes subsp. atrorubens native to California?
Yes. Trifolium longipes subsp. atrorubens is native to California (recorded as native).
When does Trifolium longipes subsp. atrorubens bloom?
Trifolium longipes subsp. atrorubens blooms Jun-Sep.
What plant family does Trifolium longipes subsp. atrorubens belong to?
Trifolium longipes subsp. atrorubens is in the Fabaceae family, genus Trifolium.
What habitat does Trifolium longipes subsp. atrorubens grow in?
Trifolium longipes subsp. atrorubens grows in dry or boggy meadows, open slopes, woodland, subalpine.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · 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.