Taxon  Report   2118 
Cirsium arvense  (L.) Scop.
Canada thistle
Cirsium arvense
© 2007 Luigi Rignanese
Click on a photo to see it bigger.
CalPhotos
Cirsium arvense
© 2009 Phil Pullen
Cirsium arvense, a dicot, is a perennial herb that is not native to California; it was introduced from elsewhere and naturalized in the wild.
It is an invasive plant. The California Invasive Plant Council classifies its potential impact on native ecosystems as moderate (plant profile / CalWeedMapper).

Interactive Distribution Map


Observation Hotline
(observation details + photos)



point, line, or polygon

one or more occurrences
within a 7.5-minute quadrangle

Plant Characteristics
and Associations



Bloom Period
Cirsium arvense
© 2008 Keir Morse
Family: ASTERACEAE  
Genus: Cirsium
Community:
wetland-riparian
Wetlands:Equally likely to occur in wetlands or non wetlands [U.S. Fish & Wildlife Service.]
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
More information about  Cirsium arvense
Photos on CalPhotos / Google Images
UC Integrated Pest Management Weed Photo Gallery
(profile of this plant as an agricultural weed)

Jepson eFlora

Records from the Consortium of California Herbaria

Original Publication citation (ITIS)

USDA PLANTS Profile (CIAR4)

Search the International Plants Names Index

Search efloras.org (Flora of North America)

website references from Google


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]. 2016. Berkeley, California: The Calflora Database [a non-profit organization].
Available: http://www.calflora.org/   (Accessed: Dec 09, 2016).

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