tansy ragwort USDA PLANTS Symbol: SEJA
U.S. Nativity: Exotic
Habit: Forbs/Herbs
Senecio jacobaea L.

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Taxonomic Rank: Magnoliopsida: Asterales: Asteraceae
Synonym(s): ragwort, stinking Willie
Native Range: Europe, southern Asia, North Africa ()

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

Selected Images from Invasive.orgView All Images at Invasive.org


Plant(s); plant
Eric Coombs, Oregon Department of Agriculture, Bugwood.org
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Plant(s); in flower
Faith Duncan, USDA Forest Service, Bugwood.org
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Foliage;
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
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Foliage; rosette
Joseph M. DiTomaso, University of California - Davis, Bugwood.org
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Flower(s);
Michael Shephard, USDA Forest Service, Bugwood.org
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Fruit(s);
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
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Plant(s); 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
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Infestation;
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
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Infestation;
Eric Coombs, Oregon Department of Agriculture, Bugwood.org
Additional Resolutions & Image Usage

EDDMapS Distribution:
This map is incomplete and is based only on current site and county level reports made by experts and records obtained from USDA Plants Database. For more information, visit www.eddmaps.org
 


State(s) Where Reported invasive.
Based on state level agency and organization lists of invasive plants from WeedUS database.

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U.S. National Parks where reported invasive:
Redwood National Park (California)



Invasive Listing Sources:
California Invasive Plant Council
Faith Campbell, 1998
Jil M. Swearingen, Survey of invasive plants occurring on National Park Service lands, 2000-2007
John Randall, The Nature Conservancy, Survey of TNC Preserves, 1995.
Native Plant Society of Oregon, 2008
Pacific Northwest Exotic Pest Plant Council, 1998