Wright’s nutrush (Scleria lacustris) is a non-native sedge that has been increasing in Florida wetlands. Wright’s nutrush was first recorded for Florida in 1988 in Jane Green Swamp, an herbaceous marsh in the Upper St. Johns River Basin. Populations were developing simultaneously in a broad arc across the south central Florida peninsula. In the ensuing years, new records were made far to the west and southwest of the initial Jane Green site. Present-day distribution of Wright’s nutrush extends to more than twenty natural areas in seven counties (Brevard, Hendry, Indian River, Lee, Osceola, Okeechobee, and Polk) and within four major river basins of the state (St. Johns, Kissimmee, Caloosahatchee, and Big Cypress).
Introduced populations of Wright’s nutrush remained small and localized in Florida until 2001 when hundreds of acres were reported in the Blue Cypress Water Management and Conservation Areas in the Upper Basin of the St. Johns River. Large populations have returned to these areas every year in the past ten, except the wet years of 2005 and 2010. During1999-2002, a period of extended drought, populations expanded dramatically in marshes of the Upper Kissimmee Basin, into wetlands of the Okaloacoochee Slough, and in natural areas in Lee County.
In 2005, the Florida Exotic Pest Plant Council listed Wright’s nutrush as a Category II invasive exotic, consistent with its increased abundance and frequency in natural areas. Four years later, in 2009, the council raised the ranking to Category I when recognition was made of its ability to alter the composition and structure of native wetland communities.
Text excerpted from IFAS Extension publication: Wright’s Nutrush: An Invader of Seasonal Wetlands in Florida by Colette C. Jacono and Kenneth A. Langeland (2011). View or download this file for management recommendations. “By timing significantly reduced herbicide dosage with plant growth stage, we can minimize non-target damage to native species while still achieving control of Wright’s nutrush. Our current recommendation was released this month [April 2011] as part of a fact sheet for resource managers.”
For more information about Scleria lacustris, visit the USGS website, which includes detailed ID information, a distribution map and a downloadable flyer.
View the herbarium specimen image from the University of Florida Herbarium Digital Imaging Projects.