Water Lettuce

Scientific name: Pistia stratiotes L. Royle

Common names: Water lettuce, tropical duckweed

Native To: Unknown, possibly South America, Africa, or the U.S.

Date of U.S. Introduction: First described in Florida in 1765; experts disagree as to whether water lettuce is native to the U.S.

Images: Invasive.org and Google

Means of Introduction: Unknown (possibly native to the U.S., or it may have arrived in ballast water)

Impact: Grows into dense mats that clog waterways

Current U.S. Distribution: Southern U.S., Eastern U.S.

• PLANTS Database map (see complete PLANTS Profile for county distribution and native status)
• Early Detection & Distribution Mapping System
• NAS Database map

U.S. States and U.S. National Parks Where Reported Invasive: Invasive Plant Atlas of the United States map

Management Plans: Aquatic Species

Selected Internet Resources:

• Federal Government
• State Government
• University/Academic
• International
• Organizations

Pistia stratiotes L.
Integrated Taxonomic Information System.
Taxonomy

Pistia stratiotes L. (Waterlettuce) - Aquatic Plant Information System (APIS)
DOD. USACE. Engineer Research and Development Center. Environmental Laboratory.
Identification/Description; Introduction History; Impacts; Habitat; Distribution; Dispersion; Controls

Pistia stratiotes Article Citation Search - AGRICOLA Database
USDA. National Agricultural Library.
Research; Special Note: NAL Catalog Search (resources)

Pistia stratiotes - Germplasm Resources Information Network (GRIN)
USDA. ARS. National Genetic Resources Program.
Taxonomy; Legal Aspects

Waterlettuce - Biological Control of Invasive Plants in the Eastern United States (Aug 2002)
BugwoodWiki.
Published by: USDA. Forest Service. Publication FHTET-2002-04.
Taxonomy; Identification/Description; Photographs; Introduction History; Impacts; Life Cycle; Habitat; Distribution; Controls

Plant Profile for Pistia stratiotes - PLANTS Database
USDA. NRCS. National Plant Data Center.
Taxonomy; Photographs; Distribution; Legal Aspects

Pistia stratiotes - Nonindigenous Aquatic Species Database
DOI. USGS. Southeast Ecological Science Center.
Identification/Description; Photographs; Introduction History; Impacts; Distribution; Special Note: Distribution maps and collection information (State and County)

Weed Alert: Water-lettuce (PDF | 408 KB)
Florida Department of Environmental Protection. Bureau of Invasive Plant Management.
Identification/Description; Photographs; Illustrations; Introduction History; Impacts; Distribution

Not Wanted: Water Lettuce (PDF | 142 KB)
Maryland Department of Natural Resources.
Identification/Description; Photographs; Introduction History; Impacts; Distribution; Legal Aspects

Invasive Water Lettuce Harms Bay Grasses And May Impede Boating
Maryland Department of Natural Resources.
Photographs; Impacts

Water Lettuce - Literature Review (PDF | 693 KB)
Wisconsin Department of Natural Resources.
Photographs; Impacts; Habitat; Life Cycle; Distribution; Dispersion; Controls; Legal Aspects

Pistia stratiotes (Water lettuce) - Invasive Plant Atlas of New England (IPANE)
University of Connecticut. Ecology and Evolutionary Biology.
Taxonomy; Identification/Description; Photographs; Introduction History; Impacts; Habitat; Distribution; Dispersion

Pistia stratiotes L. - Identification and Biology of Non-Native Plants in Florida's Natural Areas (PDF | 65 KB)
University of Florida.
Identification/Description; Photographs; Introduction History; Impacts; Life Cycle; Distribution; Dispersion

Pistia stratiotes
University of Florida. IFAS. Center for Aquatic and Invasive Plants.
Identification/Description; Photographs; Introduction History; Habitat; Distribution; Controls; Legal Aspects; Special Note: Video of Water Lettuce

Water Lettuce - Invasive Plant Atlas of the United States
University of Georgia. Center for Invasive Species and Ecosystem Health.
Taxonomy; Identification/Description; Photographs; Introduction History; Distribution

Water Lettuce - Exotic Aquatics on the Move
National Sea Grant Network and Geographic Education Alliances.
Identification/Description; Photographs; Introduction History; Impacts; Life Cycle; Habitat; Distribution; Controls

Water Lettuce - Aquaplant
Texas A&M University. Texas Agricultural Extension Service.
Identification/Description; Photographs; Illustrations; Introduction History; Controls

Weed Identification: Water Lettuce
Australian Weeds Committee. Weeds Australia.
Identification/Description; Photographs; Distribution; Dispersion

Water Lettuce
Environment Bay of Plenty Regional Council (New Zealand).
Identification/Description; Photograph; Impacts, Habitat; Distribution; Controls

Biological control of water lettuce, Pistia stratiotes
Commonwealth Scientific and Industrial Research Organisation (Australia).
Photographs; Introduction History; Impacts; Controls

Pistia stratiotes: Water lettuce
European and Mediterranean Plant Protection Organization.
Identification/Description; Impacts; Life Cycle; Habitat; Distribution; Dispersion; Controls

Weed Profile: Water lettuce
New South Wales Department of Primary Industries (Australia).
Identification/Description; Photographs; Impacts; Distribution; Dispersion; Controls; Legal Aspects

Water lettuce - Invasive Plants and Animals Fact Sheet (PDF | 229 KB)
Queensland Department of Primary Industries and Fisheries (Australia).
Identification/Description; Photographs; Impacts; Life Cycle; Habitat; Controls; Legal Aspects

Water Lettuce
Southern Tablelands and South Coast Noxious Plants Committee (Australia).
Identification/Description; Photographs; Impacts; Habitat; Dispersion; Controls

Pistia stratiotes (aquatic plant) - ISSG Global Invasive Species Database
World Conservation Union. Invasive Species Specialist Group.
Identification/Description; Photographs; Impacts; Life Cycle; Habitat; Distribution; Dispersion; Controls

Water lettuce
Guide to Invasive Plants of the Galveston Bay Area.
Identification/Description; Photographs; Introduction History; Impacts; Habitat; Distribution; Dispersion; Controls

Invader of the Month - Water Lettuce (Jan 2008)
Maryland Invasive Species Council.
Identification/Description; Photographs; Introduction History; Impacts; Controls

Pistia stratiotes
Pacific Island Ecosystems at Risk.
Identification/Description; Photographs; Habitat; Distribution; Controls