purple starthistle USDA PLANTS Symbol: CECA2
U.S. Nativity: Exotic
Habit: Forbs/Herbs
Centaurea calcitrapa L.

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Taxonomic Rank: Magnoliopsida: Asterales: Asteraceae
Synonym(s): red starthistle
Native Range: Africa, temp. Asia, Europe (GRIN);

Appearance
Centaurea calcitrapa is a biennial to perennial plant. It grows 2-3 ft. (0.61-0.91 m) tall.
Foliage
The stems and leaves are covered with fine hairs. Lower and basal leaves are divided or deeply lobed. Leaves become less divided toward the apex of the plant.
Flowers
Flowering occurs from July to October, when purple to pink blooms develop at the ends of the stems. Floral bracts are tipped with 1 in. (2.5 cm) long, straw colored spines.
Fruit
The fruit is an achene 0.08-0.16 in. (2-4 mm) long which lacks a pappus.
Ecological Threat
A native of southern Europe, Centaurea calcitrapa produces prolific seeds and often invades floodplains, dry forests and grasslands.

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


Plant(s);
Barry Rice, sarracenia.com, Bugwood.org
Additional Resolutions & Image Usage

Plant(s);
Barry Rice, sarracenia.com, Bugwood.org
Additional Resolutions & Image Usage

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

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

Flower(s);
Barry Rice, sarracenia.com, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Malcolm Storey, BioImages - Virtual Field-Guide, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
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

Feature(s); Sharp spines
Barry Rice, sarracenia.com, Bugwood.org
Additional Resolutions & Image Usage

Fruit(s);
Barry Rice, sarracenia.com, Bugwood.org
Additional Resolutions & Image Usage

Fruit(s); Fruits aligned with the stylar end at the top.
D. Walters and C. Southwick, USDA, Bugwood.org
Additional Resolutions & Image Usage

Fruit(s); Close-up.
D. Walters and C. Southwick, USDA, 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
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.