Rumex californicus
California dock
(c) Tyler Ekholm, some rights reserved (CC BY) · licence
Family: Polygonaceae · Type: Perennial · Native
Rumex californicus (California dock) is a native California perennial in the Polygonaceae family, recognized by . Narrow leaves and lack of tubercles are key features.
California dock is a native perennial found in California's mountains and coastal regions in moist places at elevations below 3,500 meters. Flowering from May to September, this plant produces small greenish-brown flowers in dense whorled clusters along branching stems. Growing with ascending stems 30 to 60 centimeters tall and often developing axillary shoots, it spreads with a vertical taproot. Its leaves are distinctive, measuring 5 to 10 centimeters long and 1 to 3 centimeters wide, with a linear to lance-oblanceolate shape, entire margins, and acute or tapered tips. The fruit is small, about 2 millimeters long, developing in shades of brown to dark red-brown.
Identification and appearance
Key characters: 21 sympatric species. Narrow leaves and lack of tubercles are key features.
Habitat and range
Habitat: Moist places
Elevation: < 3500 m
California counties: San Diego, Riverside, Tulare, San Bernardino, Los Angeles, Tuolumne, Mono, El Dorado, San Francisco, San Luis Obispo, Sutter, Tehama, Trinity, Alameda, Butte, Fresno, Glenn, Inyo, Lake, Plumas, Alpine, Amador, Kern, Madera, Marin, Mariposa, Mendocino, Merced, Napa, San Benito, San Joaquin, San Mateo, Santa Barbara, Santa Clara, Santa Cruz, Sierra, Sonoma, Ventura, Contra Costa, Humboldt, Modoc, Monterey, Nevada, Stanislaus, Orange
Outside California: Oregon, Nevada, Arizona, possibly northern Mexico
Bloom period
Rumex californicus blooms May-Sep.
How to tell it apart
vs Anemopsis: Rumex has dense flower clusters; Anemopsis has a single white cone-like flower head.; vs Amaranthus: Rumex has papery three-winged fruits; Amaranthus has small round seeds with papery covers.; vs Plantago: Rumex has branching flower clusters; Plantago has flowers in dense cylindrical spikes.; vs Eriogonum: Rumex has large broad leaves; Eriogonum typically has small basal leaf rosettes or mats.; vs Limonium: Rumex has green to reddish flower clusters; Limonium has papery purple or pink flowers.
Frequently asked questions
Is Rumex californicus native to California?
Yes. Rumex californicus is native to California (recorded as native).
When does Rumex californicus bloom?
Rumex californicus blooms May-Sep.
Where in California does Rumex californicus grow?
Rumex californicus occurs in San Diego, Riverside, Tulare, San Bernardino, Los Angeles, Tuolumne, Mono, El Dorado and other counties, at elevations of < 3500 m.
What plant family does Rumex californicus belong to?
Rumex californicus is in the Polygonaceae family, genus Rumex.
What habitat does Rumex californicus grow in?
Rumex californicus grows in Moist places.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-09-30
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.