tansy ragwort

Asterales > Asteraceae > Senecio jacobaea L.
Synonym(s): ragwort, stinking Willie

Tansy ragwort is a biennial to short-lived perennial herb native to Eurasia. Plants can reach 1-4 ft. (0.3-1.2 m) tall. Cauline (stem) leaves are sessile and deeply lobed. Flowering occurs in summer to early fall, when yellow, daisy-like flowers develop in a flat topped inflorescence at the apex of the stems. Flower heads are 0.8 in. (2 cm) in diameter. Fruit are small and have a persistent ring of white hairs (pappus) attached. Tansy ragwort is native to Europe and was possibly introduced into the United States as a medicinal plant. Plants invade pastures, open forests, swamps, riverbeds and disturbed areas.


Identification, Biology, Control and Management Resources

  • Weeds of the Week - USDA Forest Service, Northeastern Area, Forest Health Protection

Selected Images from Invasive.org

Click on each thumbnail to download the image at 1536x1024 resolution or below for available resolutions.
Use 768x512 for Microsoft PowerPoint and use 1536x1024 for Prints and Publications.

Seedling(s);
Utah State University Archive, Utah State University, Bugwood.org
768x512 / 1536x1024

Flower(s);
Michael Shephard, USDA Forest Service, Bugwood.org
768x512 / 1536x1024

Fruit(s);
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
768x512

Plant(s); in flower
Eric Coombs, Oregon Department of Agriculture, Bugwood.org
768x512 / 1536x1024

Plant(s);
Eric Coombs, Oregon Department of Agriculture, Bugwood.org
768x512 / 1536x1024

Plant(s); in flower
Tom Heutte, USDA Forest Service, Bugwood.org
768x512 / 1536x1024

Plant(s); in flower
Faith Duncan, USDA Forest Service, Bugwood.org
768x512 / 1536x1024

Infestation;
Eric Coombs, Oregon Department of Agriculture, Bugwood.org
768x512 / 1536x1024

Diagram or Graphic; Britton, N.L., and A. Brown. 1913. Illustrated flora of the northern states and Canada. Vol. 3: 542.
USDA PLANTS Database, USDA NRCS PLANTS Database, Bugwood.org
768x512 / 1536x1024

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
  • Connecticut - Noxious Weed Law
  • Massachusetts - Noxious Weed Law
  • Montana - Noxious Weed Law
  • Oregon - Noxious Weed Law
  • Washington - Noxious Weed Law
  • Invasive Plants: Western North America
  • Invasive Plants of the Upper Midwest
  • Invasive Plant Atlas of New England


External Links


footer line
USDA Forest Service Bugwood University of Georgia