perennial sowthistle

Asterales > Asteraceae > Sonchus arvensis L.
Synonym(s): field sowthistle, creeping sowthistle, field sow-thistle

Perennial sowthistle is a perennial herb native to Eurasia. Stems can reach 4.9 ft. (1.5 m) in height and contain milky sap. Leaves are sessile, alternate, clasping, up to 12 in. (30 cm) long and decrease in size further up the stem, margins undulate with sharp spines. Flowering occurs in June to October, when yellow, tight, dandelion-like flower heads develop at the tips of the branches. Flowers open 2-3 hours after sunrise and close about noon. Fruits are reddish, ribbed and have a tuft of hair (pappus) at the top. Perennial sowthistle occurs along roadsides, railroads and other disturbed habitat.


Identification, Biology, Control and Management Resources


Selected Images from Invasive.org

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Plant(s);
Steve Dewey, Utah State University, Bugwood.org
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Plant(s);
Steve Dewey, Utah State University, Bugwood.org
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Foliage;
Steve Dewey, Utah State University, Bugwood.org
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Feature(s); Stem
Michael Shephard, USDA Forest Service, Bugwood.org
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Flower(s);
Theodore Webster, USDA Agricultural Research Service, Bugwood.org
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Flower(s);
Ohio State Weed Lab Archive, Ohio State University, Bugwood.org
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Flower(s);
Tom Heutte, USDA Forest Service, Bugwood.org
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Fruit(s);
Ken Chamberlain, The Ohio State University, Bugwood.org
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Fruit(s);
David Cappaert, Michigan State University, Bugwood.org
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Fruit(s); S. oleraceus on left; S. arvensis on right
Steve Dewey, Utah State University, Bugwood.org
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Plant(s); in flower
Michael Shephard, USDA Forest Service, Bugwood.org
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Plant(s); in flower
Michael Rasy, University of Alaska, Bugwood.org
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Invasive Reference(s):

Check Invasive.org for most current lists.
  • Alaska - Noxious Weed Law
  • Arizona - Noxious Weed Law
  • California - Noxious Weed Law
  • Colorado - Noxious Weed Law
  • Illinois - Noxious Weed Law
  • Michigan - Noxious Weed Law
  • Minnesota - Noxious Weed Law
  • Nevada - Noxious Weed Law
  • South Dakota - Noxious Weed Law
  • Wyonming - Noxious Weed Law


External Links


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USDA Forest Service Bugwood University of Georgia