Oxalis incarnata
Crimson wood-sorrel, Crimson Wood-Sorrel
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Family: Oxalidaceae · Type: Herb · Not Native
Oxalis incarnata (Crimson wood-sorrel) is a non-native California herb in the Oxalidaceae family, recognized by bulblets in leaf axils and clustered leaves diagnostic.
Crimson wood-sorrel is a naturalized perennial herb found in northern Coast and San Francisco Bay Area bioregions in shady woodland habitats at elevations below 400 meters. Flowering from March to June, this plant produces white to pale pink flowers up to 2 centimeters long with distinctive sepals featuring orange tubercle tips. Growing with slender, erect stems up to 30 centimeters tall that are branched and glabrous, the plant develops axillary bulblets in stem joints. Its leaves form whirl-like clusters of fewer than 10, with petioles 2 to 7 centimeters long and small leaflets less than 1.5 centimeters in size. The plant grows from a slender rhizome with pale brown bulbs less than 2 centimeters long and distinctively beaked at the base.
Identification and appearance
Key characters: 8 sympatric species; bulblets in leaf axils and clustered leaves diagnostic
Habitat and range
Habitat: Shady woodland
Elevation: < 400 m
California counties: Santa Cruz, Alameda, San Francisco, San Mateo, Santa Barbara, Ventura, Humboldt, Napa, San Luis Obispo, Marin, Monterey
Outside California: native to southern Africa
Bloom period
Oxalis incarnata blooms Mar-Jun.
How to tell it apart
vs Trifolium: Oxalis has heart-notched leaflet tips; clover has oval or elongate leaflet tips without notches.; vs Medicago: Oxalis leaflets fold at night and have notched tips; medick leaflets don't fold and have toothed edges.; vs Marsilea: Oxalis is a land plant with flowers; water clover is aquatic with spore-bearing structures.; vs Pelargonium: Oxalis is soft-stemmed with 3 leaflets; geranium is woody-based with palmately lobed leaves.; vs Bowlesia: Oxalis has clover-like leaves with 3 leaflets; Bowlesia has kidney-shaped undivided leaves.
Frequently asked questions
Is Oxalis incarnata native to California?
No. Oxalis incarnata is not native to California (recorded as not native).
When does Oxalis incarnata bloom?
Oxalis incarnata blooms Mar-Jun.
Where in California does Oxalis incarnata grow?
Oxalis incarnata occurs in Santa Cruz, Alameda, San Francisco, San Mateo, Santa Barbara, Ventura, Humboldt, Napa and other counties, at elevations of < 400 m.
What plant family does Oxalis incarnata belong to?
Oxalis incarnata is in the Oxalidaceae family, genus Oxalis.
What habitat does Oxalis incarnata grow in?
Oxalis incarnata grows in Shady woodland.
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.