tansy ragwort
U.S. Nativity: Exotic
Habit: Forbs/Herbs
Jacobaea vulgaris Gaertn.
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Taxonomic Rank: Magnoliopsida: Asterales: Asteraceae
Appearance
Jacobaea vulgaris is a biennial to short lived perennial herb native to Eurasia. Plants can reach 1-4 ft. (0.3-1.2 m) tall.
Foliage
The leaves of the basal rosette have petioles, cauline (stem) leaves are sessile and both are deeply lobed and alternate. The leaf lobes are oblong and web-shaped. The margins of the leaves are dentate. The leaves can measure between 1.5-8 in. (4-20 cm) long and 0.75-2.25 in. (2-6 cm) wide. The leaf is medium green above, lighter underneath and occasionally tomentose.
Flowers
Flowering occurs in summer to early fall, when numerous 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
Fruit are small and have a persistent ring of white hairs (pappus) attached. 60,000-70,000 seeds produced per plant. Seeds can remain viable for up to 15 years.
Ecological Threat
J. vulgaris invades rangelands in the West where it is toxic to livestock. In the East it invades pastures, open forests, swamps, riverbeds, coastal grasslands and disturbed areas. It was first reported in the United States in the early 1900’s. It is native to most of Europe, North Africa and western Asia and may have been introduced into the United States as a medicinal plant.
Selected Images from Invasive.orgView All Images at Invasive.org


Plant(s); plant
Eric Coombs, Oregon Department of Agriculture, Bugwood.org
Additional Resolutions & Image Usage
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 NRCS PLANTS Database , USDA NRCS PLANTS Database, Bugwood.org
Additional Resolutions & Image Usage
Flower(s); flowers
Eric Coombs, Oregon Department of Agriculture, Bugwood.org
Additional Resolutions & Image Usage

Infestation;
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
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Plant(s);
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
Additional Resolutions & Image Usage
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 List
This map identifies those states that list this species on their invasive species list or law.

Invasive Listing Sources:
California Invasive Plant Council
Connecticut Invasive Plant Working Group
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
WeedUS - Database of Plants Invading Natural Areas in the United States