Oxalis micrantha
Dwarf wood-sorrel
(c) Pablo Silva, some rights reserved (CC BY) · licence
Family: Oxalidaceae · Type: Annual · Not Native
Oxalis micrantha (Dwarf wood-sorrel) is a non-native California annual in the Oxalidaceae family, recognized by annual habit and recurved fruiting pedicels diagnostic.
Dwarf wood-sorrel is a naturalized annual herb found in foothill woodlands, rock outcrops, and disturbed sites across the Sierra Nevada Foothills, central Coast Ranges, and central Coast in areas below 1,000 meters elevation. Flowering from April to May, this plant produces small yellow flowers less than 12 millimeters long in compact clusters of 6 to 14 blooms. Growing with delicate erect stems under 20 centimeters tall and covered in sparse hairs, it forms a slender, fibrous-rooted annual. Its leaves have small leaflets less than 13 millimeters long with scattered hairs and petioles under 5 centimeters in length. The fruit is small, less than 5 millimeters long, and ovoid to nearly spherical in shape.
Identification and appearance
Key characters: 7 sympatric species; annual habit and recurved fruiting pedicels diagnostic
Habitat and range
Habitat: Foothill woodland, rock outcrops, disturbed sites
Elevation: < 1000 m
California counties: Sacramento, Fresno, Marin, Calaveras, Madera, Napa, Tuolumne, San Mateo, San Luis Obispo, Monterey, San Diego, Stanislaus, San Joaquin
Outside California: South America
Bloom period
Oxalis micrantha blooms Apr-May.
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 micrantha native to California?
No. Oxalis micrantha is not native to California (recorded as not native).
When does Oxalis micrantha bloom?
Oxalis micrantha blooms Apr-May.
Where in California does Oxalis micrantha grow?
Oxalis micrantha occurs in Sacramento, Fresno, Marin, Calaveras, Madera, Napa, Tuolumne, San Mateo and other counties, at elevations of < 1000 m.
What plant family does Oxalis micrantha belong to?
Oxalis micrantha is in the Oxalidaceae family, genus Oxalis.
What habitat does Oxalis micrantha grow in?
Oxalis micrantha grows in Foothill woodland, rock outcrops, disturbed sites.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-06
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.