Taxon  Report   2118 
Cirsium arvense  (L.) Scop.
Canada thistle
Cirsium arvense, a dicot, is a perennial herb that is not native to California; it was introduced from elsewhere and naturalized in the wild.
The California Invasive Plant Council classifies its potential impact on native ecosystems as moderate   (plant profile / CalWeedMapper).

 Interactive Distribution Map 

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 Distribution by County 

point, line, or polygon

one or more occurrences within a 7.5-minute quadrangle

 Plant Characteristics
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Bloom Period
Cirsium arvense
© 2008 Keir Morse
Cirsium arvense
© 2009 Phil Pullen
Cirsium arvense
© 2007 Luigi Rignanese
Wetlands:Equally likely to occur in wetlands or non wetlands [U.S. Fish & Wildlife Service.]
Genus: Cirsium
Add an Observation of  Cirsium arvense
Name Status:
Accepted by TJM2 + PLANTS + JM93
Alternate Names:
(according to)

PLANTS: Breea arvensis
PLANTS: Cirsium setosum
PLANTS: Cirsium incanum
PLANTS: Cirsium arvense var. vestitum
PLANTS: Cirsium arvense var. mite
PLANTS: Cirsium arvense var. integrifolium
PLANTS: Cirsium arvense var. horridum
PLANTS: Cirsium arvense var. argenteum
PLANTS: Carduus arvensis
PLANTS: Breea incana
PLANTS: Serratula arvensis
 Information about  Cirsium arvense  from other sources:

Photos on CalPhotos / Google Images

website references on Google

UC Integrated Pest Management Weed Photo Gallery
(profile of this plant as an agricultural weed)

Jepson eFlora (TJM2)

Records from the Consortium of California Herbaria

Original Publication citation. on the International Plants Names Index

Search (Flora of North America)

Suggested Citation
Calflora: Information on California plants for education, research and conservation,
with data contributed by public and private institutions and individuals, including the Consortium of California Herbaria.
[web application]. 2015. Berkeley, California: The Calflora Database [a non-profit organization].
Available:   (Accessed: Mar 31, 2015).

The information on this page comes from diverse sources. None of the links are sponsored.

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