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ARS Home » Plains Area » Sidney, Montana » Northern Plains Agricultural Research Laboratory » Pest Management Research » Research » Publications at this Location » Publication #361832
Research Project: Biological Control and Community Restoration Strategies for Invasive Weed Control in the Northern Great Plains Rangelands

Location: Pest Management Research

Title: Carduus cinereus (Asteraceae), new to North America

Author
item Gaskin, John
item COOMBS, ERIC - Oregon Department Of Agriculture
item KELCH, DEAN - California Department Of Food And Agriculture
item KEIL, DAVID - California Polytechnic State University
item PORTER, MARK - Oregon Department Of Agriculture
item SUSANNA, ALFONSO - Botanical Research Institute

Submitted to: Madrono
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/3/2019
Publication Date: 1/22/2020
Citation: Gaskin, J.F., Coombs, E., Kelch, D., Keil, D., Porter, M., Susanna, A. 2020. A species of plumeless thistle, Carduus cinereus (Asteraceae), new to North America. Madrono. 66(4):142-147. https://doi.org/10.3120/0024-9637-66.4.142.
DOI: https://doi.org/10.3120/0024-9637-66.4.142

Interpretive Summary: A new exotic thistle species (Carduus cinereus) has been discovered in the Hells Canyon Wilderness of northeastern Oregon and in adjacent areas of western Idaho. These plants were initially identified as C. pycnocephalus but are found by our DNA analyses to be genetically distinct. This non-native species is new to North America, and is likely a problematic invader, as are other Carduus species. A revised key to identify species of Carduus in North America is presented.

Technical Abstract: Carduus cinereus M. Bieb. populations have been discovered in the Hells Canyon Wilderness of northeastern Oregon and in adjacent areas of western Idaho. These plants were initially identified as C. pycnocephalus but are distinguished from that species by loosely clustered, usually pedunculate heads, and scarious-margined phyllaries. These plants are also genetically distant from other North American Carduus species (<94% similarity) for the internal transcribed spacers between the18S and 26S nuclear rDNA regions. This non-native species is new to North America. A revised key to species of Carduus in North America is presented.