logo Calflora, a 501c3 non-profit
Taxon  Report  
Ambrosia chamissonis  (Less.) Greene
Beach bur,   Silver beachweed
Ambrosia chamissonis is a perennial herb that is native to California, and also found elsewhere in western North America.
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
DJJJASONAFMM

Bloom Period
Genus: Ambrosia
Family: Asteraceae  
Category: angiosperm  
PLANTS group:Dicot
Jepson eFlora section: eudicot

Habitat: coastal

Communities: Coastal Strand

Name Status:
Accepted by JEF + JEF + PLANTS + POWO

Alternate Names:
OTHERAmbrosia bipinnatifida
JEF + PLANTSAmbrosia chamissonis var. bipinnatisecta
JEF + PLANTSFranseria chamissonis ssp. bipinnatisecta
OTHERFranseria chamissonis ssp. chamissonis
PLANTSFranseria chamissonis var. bipinnatisecta
More …
Information about  Ambrosia chamissonis from other sources
Nursery availability from CNPLX
This plant is available commercially.
Jepson eFlora

USDA PLANTS Profile (AMCH4)

Photos on Calflora

Photos on CalPhotos

Google Images

Photos on iNaturalist

ID Tips on PlantID.net

[Wikipedia] Reproduction: The plant is monoecious, with male and female flowers on each individual. Staminate (male) flower heads containing many pale colored florets occur at the tip of the inflorescence, with pistillate (female) flower heads clustered below them. Each pistillate head contains a single tiny flower which develops into a fruit. The fruit is a brown bur up to a centimeter wide covered in sharp spines. (link added by Mary Ann Machi)


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. Berkeley, California: The Calflora Database [a non-profit organization]. Available: https://www.calflora.org/   (Accessed: 02/16/2025).