Family: Cyperaceae (Sedge Family)
Duration and Habit: Perennial Grass/Grasslike
Grows in robust, loose clumps to up to 40 inches high; leaves are cross-sectionally V-shaped and glossy. Leaf bases are distinctly purplish-black. Culms (stems) are strongly 3-sided. The inflorescence is terminal and consists of 5 - 11 groups of densely clustered spikelets, which are greenish-white. Culms are connected by thick rhizomes.
Ecological Threat: Rapidly spreading from disturbed to natural areas. Once established, it outcompetes native grasses and sedges, threatening local plant biodiversity. Alters habitat for the endangered Attwater's prairie chicken. A potential pest to rice agriculture.
Biology & Spread: An aggressive seed producer; large plants can produce 1 million viable seeds/year. Seeds are readily transported by water. Will flower and fruit from June through November. Also reproduces vegetatively via fragmentation and budding of rhizomes.
History: Most likely introduced via rice agriculture and was first reported in Texas from Cameron County about 20 miles north of Brownsville in 1941 (Rosen et. al, 2006). Continues to spread especially along roadsides via mowing, flooding, and soil and equipment movement.
U.S. Habitat: Thrives in disturbed, inundated soils. Will form monospecific stands in ditches, coastal prairies, low flatwoods, and fallow rice fields. Tolerant to various soil textures (sands to clays).
U.S. Nativity: Introduced to U.S.
Native Origin: South America
U.S. Present: AL, FL, LA, MS, TX
Distribution: Common in all Gulf Coast states and Georgia. Projected to spread as far north as Arkansas and the coastal plains of Virginia. Naturalized in all surrounding Galveston Bay counties, extending as far south as Matagorda and Jackson counties.
List All Observations of Cyperus entrerianus reported by Citizen Scientists
Alternatives include Big bluestem (Andropogon gerardii), Sideoats grama (Bouteloua curtipendula), and Starrush whitetop (Rhynchospora colorata).
Glyphosate is expected to achieve 98% control when applied at a rate of 2 quarts/acre. Use a 2% solution on individuals. Mowing at 2-4 week intervals suppresses seed production. Machinery should be kept clean to prevent seed spread.USE PESTICIDES WISELY: ALWAYS READ THE ENTIRE PESTICIDE LABEL CAREFULLY, FOLLOW ALL MIXING AND APPLICATION INSTRUCTIONS AND WEAR ALL RECOMMENDED PERSONAL PROTECTIVE GEAR AND CLOTHING. CONTACT YOUR STATE DEPARTMENT OF AGRICULTURE FOR ANY ADDITIONAL PESTICIDE USE REQUIREMENTS, RESTRICTIONS OR RECOMMENDATIONS. MENTION OF PESTICIDE PRODUCTS ON THIS WEB SITE DOES NOT CONSTITUTE ENDORSEMENT OF ANY MATERIAL.
Rosen, D.J., R. Carter and C.T. Bryson. 2006. The spread of Cyperus entrerianus (Cyperaceae) in the southeastern United States and its invasive potential in bottomland hardwood forests. Southeastern Naturalist 5:333-344. http://www.valdosta.edu/~rcarter/Rosen.Carter.Bryson.2006.pdf
The Quiet Invasion: A Guide to Invasive Plants of the Galveston Bay Area.
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