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 the base. The lower surface may be smooth or hairy towards the 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 enable 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.

Citations

Winston, R.L., Andreas, J.E., Milan, J., DesCamp, W., Randell, C.B., and M. Schwarzlander. 2014. New Invaders of the Southwest. United States Department of Agriculture, Forest Health Technology Enterprise Team. FHTET-2014-12. Retrieved from https://bugwoodcloud.org/resource/files/14767.pdf

Winston, R.L., Andreas, J.E., Milan, J., DesCamp, W., Randell, C.B., and M. Schwarzländer. 2014. New Invaders of the Northwest. United States Department of Agriculture, Forest Health Technology Enterprise Team. FHTET-2014-12. Retrieved from https://www.fs.fed.us/foresthealth/technology/pdfs/FHTET-2014-12_NW_New_Invaders.pdf
 

Resources

• Weed of the Week - USDA Forest Service

Selected Images

Maps

Invasive Listing Sources

• Alabama Invasive Plant Council
• California Invasive Plant Council
• 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.
• Native Plant Society of Oregon, 2008
• New Invaders of the Northwest
• New Invaders of the Southwest
• New Mexico Noxious Weeds
• South Carolina Exotic Pest Plant Council
• Washington Noxious Weeds
• WeedUS - Database of Plants Invading Natural Areas in the United States

References