Luziola subintegra

Tropical American water grass

Nonnative to FloridaFISC Category 1 Invasive

Species Overview

Photos by Mike Bodle, Senior Scientist, South Florida Water Management District (2009), Jeff Schardt, Florida Fish and Wildlife Conservation Commission (2008), and John Kunzer, Florida Fish and Wildlife Conservation Commission (2009). All photos are from Lake Okeechobee, Florida.

Native to: Mexico, Central America, Caribbean Basin, South America to Argentina

First discovered in Lake Okeechobee in 2007 and documented to be spreading. As of July 2009, 2,000 acres had been treated in this area. Summary of first detection in Florida: Two large mats of Luziola subintegra (approximately two and eighty hectares each) were found around Harney Pond Canal in Fisheating Bay of Lake Okeechobee, Glades County. In addition, both emergent aquatic and terrestrial forms were found in the mouth of Fisheating Creek. As Fisheating Creek is the only unregulated inflow to Lake Okeechobee, it was speculated that this was the point of introduction into Fisheating Bay and Lake Okeechobee.

Species Characteristics

Family: Poaceae

Habit: robust emergent or submergent grass with large, thick culms (3 mm in diameter or larger).

Leaves: inflated with spongy sheaths and long, broad blades (7 mm wide or wider), and ligules from 1-4 cm long.

Flowers: monecious, with staminate and pistillate portions in separate panicles. Staminate panicle terminal, open, one fertile floret per spikelet. Pistillate panicle axillary, congested, barely exserted from the sheath, primary branches sharply recurved when mature, one fertile floret per spikelet.

Distribution in Florida: reported from Brevard, Glades, Hendry, and Miami-Dade Counties


Spreading both vegetatively and by seed, it aggressively competes with native vegetation. Creates large dense mats pushing out and excluding other plants. The terrestrial forms of this plant that were found appeared to be less competitive against terrestrial native plants.

Control Methods

Preventive Measures

Thoroughly clean all vehicles, gear, and equipment when leaving areas where the plant is present.


More research is needed.


More research is needed.


None known.


Foliar (96 fl oz/ac/year aquatic imazapyr). Imazapyr provides best control 9-12 months after treatment under dry and flooded conditions. However, repeat treatments when dry should include glyphosate (2% glyphosate+ 0.5% imazapyr). Do not use imazapyr where forested overstory occurs. Consult an expert to develop an integrated management strategy. 

Learn more about this species

UF IFAS Assessment of Non-Native Plants in Florida’s Natural Areas

Atlas of Florida Plants


USDA Plant Database

Invasive Species Compendium

View records and images from University of Florida Herbarium

Luziola subintegra (Poaceae: Oryzeae), New to Florida and the United States, by J.M. Kunzer and M.J. Bodle. Journal of the Botanical Research Institute of Texas 2(1): 633-638. 2008.