Rumex kerneri
Kerner's dock
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Family: Polygonaceae · Type: Herb · Not Native
Rumex kerneri (Kerner's dock) is a non-native California herb in the Polygonaceae family, recognized by . Large, round fruiting structures with single tubercle distinctive.
Kerner's dock is a naturalized perennial herb found in central California bioregions including the Carrizo Plain, southern Coast Ranges, and northern coastal areas in disturbed areas, oak woodlands, and grasslands at elevations below 700 meters. Flowering from April to June, this plant produces small greenish flowers in dense, interrupted terminal clusters with whorled branches. Growing with slender stems 50 to 100 centimeters tall, it develops a vertical fusiform taproot and appears somewhat papillate. Its large oblong to lanceolate leaves measure 15 to 25 centimeters long with entire or slightly wavy margins, featuring a truncate or slightly heart-shaped base. The fruit is small, brown, and approximately 3 millimeters long with distinctive round inner perianth lobes.
Identification and appearance
Key characters: 17 sympatric species. Large, round fruiting structures with single tubercle distinctive.
Habitat and range
Habitat: Disturbed areas, oak woodland, grassland
Elevation: < 700 m
California counties: Santa Barbara, Monterey, San Luis Obispo, Tehama, Shasta, Ventura, Siskiyou
Outside California: native to southeastern Europe
Bloom period
Rumex kerneri blooms Apr-Jun.
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 kerneri native to California?
No. Rumex kerneri is not native to California (recorded as not native).
When does Rumex kerneri bloom?
Rumex kerneri blooms Apr-Jun.
Where in California does Rumex kerneri grow?
Rumex kerneri occurs in Santa Barbara, Monterey, San Luis Obispo, Tehama, Shasta, Ventura, Siskiyou, at elevations of < 700 m.
What plant family does Rumex kerneri belong to?
Rumex kerneri is in the Polygonaceae family, genus Rumex.
What habitat does Rumex kerneri grow in?
Rumex kerneri grows in Disturbed areas, oak woodland, grassland.
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.