brown knapweed USDA PLANTS Symbol: CEJA
U.S. Nativity: Exotic
Habit: Forbs/Herbs
Centaurea jacea L.

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Taxonomic Rank: Magnoliopsida: Asterales: Asteraceae
Synonym(s): brown knapweed
Native Range: Europe, n. Africa, n. & w. Asia (BAIL);

Brown knapweed is a perennial plant that grows 1-3 ft (0.3-0.9 m) tall and invades dry fields, roadsides and meadows. The basal leaves are oblanceolate to elliptic and 2-10 in. (5 -25 cm) long. Leaves become smaller and more linear as they move up the stem. Flowering occurs from June to September, when magenta flowers appear in 1-1 1/4 in. (2.5-3.2 cm) wide, solitary heads at the tips of the branches. Brown knapweed is native to Europe.

Identification, Biology, Control and Management Resources

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


Plant(s); in flower
Cindy Roche, , Bugwood.org
Additional Resolutions & Image Usage

Plant(s);
Bruce Ackley, The Ohio State University, Bugwood.org
Additional Resolutions & Image Usage

Foliage;
Bruce Ackley, The Ohio State University, Bugwood.org
Additional Resolutions & Image Usage

Foliage;
Bruce Ackley, The Ohio State University, Bugwood.org
Additional Resolutions & Image Usage

Foliage; likely Centaurea nigra - black knapweed but may be hybrid with C. jacea (C. ×moncktonii syn. C. ×pratensis)
Rob Routledge, Sault College, Bugwood.org
Additional Resolutions & Image Usage

Flower(s); seedhead
Cindy Roche, , Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Bruce Ackley, The Ohio State University, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Bruce Ackley, The Ohio State University, Bugwood.org
Additional Resolutions & Image Usage

Flower(s); likely Centaurea nigra - black knapweed but may be hybrid with C. jacea (C. ×moncktonii syn. C. ×pratensis)
Rob Routledge, Sault College, Bugwood.org
Additional Resolutions & Image Usage

Flower(s); likely Centaurea nigra - black knapweed but may be hybrid with C. jacea (C. ×moncktonii syn. C. ×pratensis)
Rob Routledge, Sault College, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Bruce Ackley, The Ohio State University, Bugwood.org
Additional Resolutions & Image Usage

Seed(s);
Bruce Ackley, The Ohio State University, 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:
Blue Ridge Parkway (North Carolina)



Invasive Listing Sources:
Faith Campbell, 1998
Jil M. Swearingen, Survey of invasive plants occurring on National Park Service lands, 2000-2007
Mid-Atlantic Exotic Pest Plant Council, 2005
Pacific Northwest Exotic Pest Plant Council, 1998
Virginia Department of Conservation and Recreation, 2009