Uruguayan pampas grass USDA PLANTS Symbol: COSE4
U.S. Nativity: Exotic
Habit: Grass or Grasslike
Cortaderia selloana (Schult. & Schult. f.) Asch. & Graebn.

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Taxonomic Rank: Liliopsida: Cyperales: Poaceae
Synonym(s): pampas grass, silver pampas grass, Uruguayan pampasgrass
Native Range: Brazil, Argentina, Chile (BAIL);

Appearance
Cortaderia selloana is a perennial in the grass family (Poaceae) growing 6-13 ft. (1.8-4 m) in height. Lateral roots can spread to 13 ft. (4 m) in diameter and 11.5 ft. (3.5 m) in depth.
Foliage
Cortaderia selloana leaf blades can get up to 6 ft. (1.8 m) long and 1-3 in. (2.5-7.6 cm) wide. They are V-shaped in cross-section, and bluish green in color. The upper surface is smooth at base. The lower surface may be smooth or hairy towards collar. Leaf tips are bristly and curled and margins are rough and sharp.
Flowers
The inflorescence is a showy dense, feathery, 1-4 ft. (0.3-0.9 m), stiff, light violet to silvery white panicle.
Fruit
The wind-dispersed seeds of Cortaderia selloana can be found at distances up to 20 mi. (32.2 km) away from the parent plant. Each female flower head can produce up to 100,000 seeds.
Ecological Threat
Cortaderia selloana requires sandy soils, ample moisture, and sunny locations. It tolerates warm summer temperatures, intense sunlight, and moderate drought. The vigorous growth habit and large size enables it to invade natural ecosystems. Cortaderia selloana can invade sandy, moist ditch banks. Vegetative reproduction can occur when root fragments develop shoots at the base of the plant. It has the ability to form dense stands where it can quickly become a fire hazard.

Identification, Biology, Control and Management Resources

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


Plant(s);
The Nature Conservancy , The Nature Conservancy, Bugwood.org
Additional Resolutions & Image Usage

Plant(s);
The Nature Conservancy , The Nature Conservancy, Bugwood.org
Additional Resolutions & Image Usage

Plant(s); female plant.
Joseph M. DiTomaso, University of California - Davis, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
The Nature Conservancy , The Nature Conservancy, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Joy Viola, Northeastern University, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Joy Viola, Northeastern University, Bugwood.org
Additional Resolutions & Image Usage

Flower(s); male right and female
Joseph M. DiTomaso, University of California - Davis, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Lesley Ingram, , Bugwood.org
Additional Resolutions & Image Usage

Stem(s); collar and sheath.
Joseph M. DiTomaso, University of California - Davis, Bugwood.org
Additional Resolutions & Image Usage

Floret(s); Pair of attached male florets, plus sterile apical floret.
D. Walters and C. Southwick, USDA, Bugwood.org
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Floret(s); Lateral view of a female floret.
D. Walters and C. Southwick, USDA, Bugwood.org
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Fruit(s); Caryopses in dorsal (left), lateral (middle), and ventral (right) views. Apices at top.
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.

U.S. National Parks where reported invasive:
Glen Canyon National Recreation Area (Utah)
Grand Canyon National Park (Arizona)



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.
National  Wildlife Refuge Association, Silent Invasion: A Call to Action from the National Wildlife Refuge Association, 2002. Washington DC. 17 pp.
Native Plant Society of Oregon, 2008
South Carolina Exotic Pest Plant Council