squarrose knapweed USDA PLANTS Symbol: CEVI
U.S. Nativity: Exotic
Habit: Forbs/Herbs
Centaurea virgata Lam.

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Taxonomic Rank: Magnoliopsida: Asterales: Asteraceae
Native Range: central and southern Europe (BAIL);

Appearance
Centaurea virgata is a perennial forb that can grow 12-18 in. (30.5-45.7 cm) tall. This species is sometimes confused with diffuse knapweed (Centaurea diffusa), but can be distinguished from Centaurea diffusa by the floral bracts. Bracts on Centaurea virgata are curved outward and are not laterally toothed.
Foliage
The leaves are alternate and deeply dissected.
Flowers
Flowering occurs in early to mid-summer, when pink flowers develop in heads at the tips of the branches.
Fruit
Seeds are dispersed when the plant breaks off at the base and tumbles across the landscape dispersing seeds along the way.
Ecological Threat
Occurs in open disturbed sites, such as rangelands, roadsides, and grasslands. Centaurea virgata is native to the Mediterranean region.

Identification, Biology, Control and Management Resources

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


Plant(s); from the eastern Mediterranean region is spreading on rangelands in the western United States.
Steve Dewey, Utah State University, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Steve Dewey, Utah State University, Bugwood.org
Additional Resolutions & Image Usage

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

Flower(s);
Steve Dewey, Utah State University, Bugwood.org
Additional Resolutions & Image Usage

Plant(s); in flower
Steve Dewey, Utah State University, Bugwood.org
Additional Resolutions & Image Usage

Infestation;
Sara Rosenthal, USDA Agricultural Research Service, Bugwood.org
Additional Resolutions & Image Usage

Plant(s);
USDA Agricultural Research Service , USDA Agricultural Research Service, Bugwood.org
Additional Resolutions & Image Usage

Plant(s);
USDA Agricultural Research Service , USDA Agricultural Research Service, Bugwood.org
Additional Resolutions & Image Usage

Infestation;
Steve Dewey, Utah State University, Bugwood.org
Additional Resolutions & Image Usage

Infestation;
Steve Dewey, Utah State University, Bugwood.org
Additional Resolutions & Image Usage

Plant(s); post-fire emergence
Steve Dewey, Utah State University, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Joseph M. DiTomaso, University of California - Davis, 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.


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