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Taxon  Report  
Xanthium strumarium  L.
Rough cockleburr
Xanthium strumarium is an annual herb that is native to California, and also found elsewhere in North America and beyond.
Siskiyou Del Norte Modoc Humboldt Shasta Lassen Trinity Plumas Tehama Butte Mendocino Glenn Sierra Yuba Lake Nevada Colusa Placer Sutter El Dorado Yolo Alpine Napa Sonoma Sacramento Mono Amador Solano Calaveras Tuolumne San Joaquin Marin Contra Costa Alameda Santa Cruz Mariposa Madera San Francisco San Mateo Merced Fresno Stanislaus Santa Clara Inyo San Benito Tulare Kings Monterey San Bernardino San Luis Obispo Kern Santa Barbara Ventura Los Angeles Riverside Orange San Diego Imperial
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Bloom Period
Genus: Xanthium
Family: Asteraceae  
Category: angiosperm  
PLANTS group:Dicot
Jepson eFlora section: eudicot

Toxicity: Do not eat any part of this plant.

Wetlands: Equally likely to occur in wetlands and non wetlands

Habitat: disturbed

Communities: wetland-riparian, weed, characteristic of disturbed places

Name Status:
Accepted by PLANTS + POWO
Alternate Names:
OTHERXanthium calvum
Information about  Xanthium strumarium from other sources
Nursery availability from CNPLX
Commercial availability unknown.
USDA PLANTS Profile (XAST)

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Suggested Citation
Calflora: Information on California plants for education, research and conservation, with data contributed by public and private institutions and individuals. [web application]. 2025. The Calflora Database [a non-profit organization]. Available: https://www.calflora.org/   (Accessed: 05/18/2025).