spiny plumeless thistle

Asterales > Asteraceae > Carduus acanthoides L.
Synonym(s): plumeless thistle

Spiny plumeless thistle is an annual or biennial herbaceous plant that grows to 5 ft. (1.5 m) tall. It is an invader of pastures and other disturbed areas throughout parts of the western, central, and northeastern United States, as well as southern Canada. Flowering occurs from May to August. The flower heads are red to purple in color and up to 1 in. (2.5 cm) in diameter. Flower stems are branched with spiny wings extending to the flower heads. Hybridization with musk thistle (C. nutans) has been observed. Spiny plumeless thistle infests open, disturbed areas such as pastures, roadsides, and railroad right-of-ways. It can form dense stands that reduce the forage potential of pastures and suppress the growth of more desirable vegetation. Spiny plumeless thistle is native to Europe and Asia and was first discovered in the United States in Camden, New Jersey in 1878.


Identification, Biology, Control and Management Resources


Selected Images from Invasive.org

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Foliage;
Todd Pfeiffer, Klamath County Weed Control, Bugwood.org
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Foliage;
Steve Dewey, Utah State University, Bugwood.org
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Flower(s);
Todd Pfeiffer, Klamath County Weed Control, Bugwood.org
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Flower(s);
Gary L. Piper, Washington State University, Bugwood.org
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Flower(s);
Steve Dewey, Utah State University, Bugwood.org
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Plant(s);
Gary L. Piper, Washington State University, Bugwood.org
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Plant(s);
Todd Pfeiffer, Klamath County Weed Control, Bugwood.org
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Plant(s);
Todd Pfeiffer, Klamath County Weed Control, Bugwood.org
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Plant(s); in flower
Todd Pfeiffer, Klamath County Weed Control, Bugwood.org
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Invasive Reference(s):

Check Invasive.org for most current lists.
  • Arizona - Noxious Weed Law
  • California - Noxious Weed Law
  • California - Invasive Plant Inventory
  • Colorado - Noxious Weed Law
  • Maryland - Noxious Weed Law
  • Michigan - Noxious Weed Law
  • Minnesota - Noxious Weed Law
  • Nebraska - Noxious Weed Law
  • North Carolina - Noxious Weed Law
  • Oregon - Noxious Weed Law
  • South Dakota - Noxious Weed Law
  • Washington - Noxious Weed Law
  • West Virginia - Noxious Weed Law
  • Wyonming - Noxious Weed Law
  • Mid-Atlantic - EPPC List
  • Invasive Plants: Western North America
  • Invasive Plants of the Upper Midwest


External Links


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USDA Forest Service Bugwood University of Georgia