meadow hawkweed USDA PLANTS Symbol: HICA10
U.S. Nativity: Exotic
Habit: Forbs/Herbs
Hieracium caespitosum Dumort.

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Taxonomic Rank: Magnoliopsida: Asterales: Asteraceae
Synonym(s): yellow hawkweed
Native Range: Not Found (BAIL);

Appearance
Hieracium caespitosum is a perennial plant in the sunflower family. It grows from 1-3 ft. (0.3-0.9 m) tall and produces a milky sap when crushed.
Foliage
Leaves long and narrow, up to 6 in. (15.2 cm) long, somewhat hairy on both sides, and form a basal rosette. There are also one or two small leaves found on the stem.
Flowers
Flowers are yellow, dandelion-like, and develop in summer to fall. Flowers in bud are rounded and black in tight clusters on top of the stems.
Fruit
25-30 seeds can be found on one fruit and have fine white bristles which aid in wind dispersal. The plant can spread by seed, stolon, and rhizome.
Ecological Threat
Hieracium caespitosum is native to Europe and occurs in fields, roadsides and sparse woodlands. It was first found in the United States in Washington in 1969.

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


Infestation;
Linda Wilson, University of Idaho, Bugwood.org
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Infestation;
Linda Wilson, University of Idaho, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Tom Heutte, USDA Forest Service, Bugwood.org
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Stem(s);
Tom Heutte, USDA Forest Service, Bugwood.org
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Stem(s); Stem
Tom Heutte, USDA Forest Service, Bugwood.org
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Plant(s);
Michael Shephard, USDA Forest Service, Bugwood.org
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Flower(s);
Michael Shephard, USDA Forest Service, Bugwood.org
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Flower(s);
Elizabeth Bella, USDA Forest Service, Bugwood.org
Additional Resolutions & Image Usage

Plant(s); Britton, N.L., and A. Brown. 1913. Illustrated flora of the northern states and Canada. Vol. 3: 333.
USDA PLANTS Database, USDA NRCS PLANTS Database, Bugwood.org
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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.

U.S. National Parks where reported invasive:
Yellowstone National Park (Wyoming)



Invasive Listing Sources:
Faith Campbell, 1998
Pacific Northwest Exotic Pest Plant Council, 1998