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Taxon  Report  
Carduus pycnocephalus  L.
Italian thistle
Carduus pycnocephalus is an annual herb that is not native to California.
Cal-IPC rating: moderate
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Observation Search
~11690 records in California
redone or more occurrences
within a 7.5-minute quadrangle
DJJJASONAFMM

Bloom Period
Subspecies and Varieties:
Genus: Carduus
Family: Asteraceae  
Category: angiosperm  
PLANTS group:Dicot
Jepson eFlora section: eudicot

Habitat: disturbed

Communities: weed, characteristic of disturbed places

Name Status:
Accepted by PLANTS

Information about  Carduus pycnocephalus from other sources
USDA PLANTS Profile (CAPY2)

Photos on Calflora

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Photos on iNaturalist

[Wikipedia] Origins: Carduus pycnocephalus, with common names including Italian thistle, Italian plumeless thistle, and Plymouth thistle, is a species of thistle. It is native to: the Mediterranean region in southern Europe, North Africa, and Western Asia; East Europe and the Caucasus; and the Indian Subcontinent. The plant has become an introduced species in other regions, and on other continents, often becoming a noxious weed or invasive species. (contributed by Jessica Johnston)

[CNPS SLO] Introduction: A member of the Asteraceae family, Italian thistle is an annual herb native to the Mediterranean region and is widespread in California, Oregon and Washington, however it is not found east of the Sierra Nevada. It was accidentally introduced into United States (Batra et al. 1981) and California (Goeden 1974) in the 1930s. Robbins (1940) reports it as early as 1912 near Fort Bragg in Mendocino County. (contributed by Jessica Johnston)


Suggested Citation
Calflora: Information on California plants for education, research and conservation, with data contributed by public and private institutions and individuals. [web application]. 2024. Berkeley, California: The Calflora Database [a non-profit organization]. Available: https://www.calflora.org/   (Accessed: 03/28/2024).