Rumex conglomeratus
Clustered dock
(c) Douglas Goldman, some rights reserved (CC BY-SA), uploaded by Douglas Goldman · licence
Family: Polygonaceae · Type: Herb · Not Native
Rumex conglomeratus (Clustered dock) is a non-native California herb in the Polygonaceae family, recognized by . Three equal, large tubercles and short pedicels diagnostic.
Clustered dock is a naturalized perennial herb found in California's Foothill Woodlands and Southeastern Great Basin regions in moist places at elevations below 1,500 meters. Flowering from May to August, this plant produces small greenish flowers in dense, interrupted clusters with thread-like pedicels. Growing with erect stems 30 to 80 centimeters tall and a vertical fusiform taproot, it develops lanceolate to lance-ovate leaves 10 to 30 centimeters long with entire margins. Its leaves have a distinctive base that ranges from tapered to slightly heart-shaped, with a relatively flat margin and slightly acute tip. The fruit is small, generally dark red-brown, and measures 1.5 to 2 millimeters long.
Identification and appearance
Key characters: 20 sympatric species. Three equal, large tubercles and short pedicels diagnostic.
Habitat and range
Habitat: Common. Moist places
Elevation: < 1500 m
California counties: Contra Costa, Los Angeles, Ventura, Kern, Butte, Riverside, Humboldt, Mendocino, Inyo, Orange, San Bernardino, Lake, Santa Barbara, Fresno, San Diego, San Luis Obispo, Marin, Monterey, Sacramento, Plumas, Madera, Sonoma, Amador, Nevada, El Dorado, Alameda, Merced, Napa, San Joaquin, Siskiyou, Solano, Sutter, Tuolumne, Yolo, Yuba, Del Norte, San Mateo, San Francisco, Santa Clara, Santa Cruz, Tulare, Stanislaus, Mariposa, Shasta, Imperial, Colusa
Outside California: native to Europe
Bloom period
Rumex conglomeratus blooms May-Aug.
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 conglomeratus native to California?
No. Rumex conglomeratus is not native to California (recorded as not native).
When does Rumex conglomeratus bloom?
Rumex conglomeratus blooms May-Aug.
Where in California does Rumex conglomeratus grow?
Rumex conglomeratus occurs in Contra Costa, Los Angeles, Ventura, Kern, Butte, Riverside, Humboldt, Mendocino and other counties, at elevations of < 1500 m.
What plant family does Rumex conglomeratus belong to?
Rumex conglomeratus is in the Polygonaceae family, genus Rumex.
What habitat does Rumex conglomeratus grow in?
Rumex conglomeratus grows in Common. 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 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.