Oxalis smalliana
Redwood sorrel
(c) Ed Alverson, some rights reserved (CC BY), uploaded by Ed Alverson · licence
Family: Oxalidaceae · Type: Perennial · Native
Oxalis smalliana (Redwood sorrel) is a native California perennial in the Oxalidaceae family, recognized by specific redwood forest habitat.
Redwood sorrel is a California native perennial found in moist conifer forests, particularly among coast redwood, at elevations below 700 meters. Flowering from January to August, this plant produces delicate white to pink or purple flowers with a distinctive yellow to yellow-orange spot at the base of each petal, typically 1.5 to 2.5 centimeters long. Growing with a creeping, fleshy rhizome and nearly stemless, it forms clustered leaflets at the rhizome tips, with petioles up to 23 centimeters long. Its leaves are composed of three leaflets up to 3.5 centimeters long, often with a purple tinge on the undersides and pale midribs. The plant produces ovoid fruits approximately 10 millimeters long, emerging from peduncles up to 22 centimeters in length.
Identification and appearance
Key characters: Geographically isolated; specific redwood forest habitat
Habitat and range
Habitat: Moist conifer forest, primarily among coast redwood
Elevation: < 700 m
California counties: San Mateo, Humboldt, Mendocino, Marin, Sonoma, Monterey, Santa Cruz, Del Norte, Santa Barbara, Santa Clara, Trinity, Butte, Alameda, Contra Costa, San Luis Obispo, Napa
Outside California: to southwestern Oregon
Bloom period
Oxalis smalliana blooms Jan-Aug.
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 smalliana native to California?
Yes. Oxalis smalliana is native to California (recorded as native).
When does Oxalis smalliana bloom?
Oxalis smalliana blooms Jan-Aug.
Where in California does Oxalis smalliana grow?
Oxalis smalliana occurs in San Mateo, Humboldt, Mendocino, Marin, Sonoma, Monterey, Santa Cruz, Del Norte and other counties, at elevations of < 700 m.
What plant family does Oxalis smalliana belong to?
Oxalis smalliana is in the Oxalidaceae family, genus Oxalis.
What habitat does Oxalis smalliana grow in?
Oxalis smalliana grows in Moist conifer forest, primarily among coast redwood.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-08
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.