An official website of the United States government

The .gov means it’s official.
Federal government websites always use a .gov or .mil domain. Before sharing sensitive information online, make sure you’re on a .gov or .mil site by inspecting your browser’s address (or “location”) bar.

This site is also protected by an SSL (Secure Sockets Layer) certificate that’s been signed by the U.S. government. The https:// means all transmitted data is encrypted  — in other words, any information or browsing history that you provide is transmitted securely.

U.S. Department of Agriculture
National Invasive Species Information Center
You are here
Home » Species Profiles » Aquatic Invasives » Aquatic Plants » Hydrilla

Hydrilla

Hydrilla
Scientific Name:
Hydrilla verticillata (L. f.) Royle (ITIS)
Common Name:
Hydrilla, Florida elodea, water thyme, Indian star-vine
Photo:
Hydrilla, plants - Photo by Raghavan Charudattan; University of Florida
Native To:
Eastern Hemisphere; U.S. strains possibly originated in Asia (Balciunas et al. 2002)
Date of U.S. Introduction:
1950s (Masterson 2007)
Means of Introduction:
Aquarium trade (Masterson 2007)
Impact:
Crowds out native species; impedes irrigation and boating (Balciunas et al. 2002)

Distribution/Maps/Survey Status

Federally Regulated

  • Noxious Weeds Program

    USDA. APHIS. Plant Protection and Quarantine.

    Includes species listed as a Federal Noxious Weed under the Plant Protection Act, which makes it illegal in the U.S. to import or transport between States without a permit.

Images

Videos

Selected Resources

The section below contains selected highly relevant resources for this species, organized by source. To view all related content for this species, click on "View all resources for species" in the top left of this page.

Council or Task Force

Fact Sheet: Hydrilla (Apr 2016) (PDF | 496 KB)
Alberta Invasive Species Council (Canada).
See also: Fact Sheets for more information about individual invasive species, including those listed as "Prohibited Noxious" and "Noxious" under the Alberta Weed Control Act
Invasive Plants of California's Wildlands - Hydrilla verticillata

California Invasive Plant Council.
In online book: Bossard, C.C., J.M. Randall, and M.C. Hoshovsky (Editors). 2000. Invasive Plants of California's Wildlands. University of California Press. Berkeley, CA
Priority Species: Hydrilla
Washington State Recreation and Conservation Office. Washington Invasive Species Council.
Southeast Exotic Pest Plant Council Invasive Plant Manual - Hydrilla
Southeast Exotic Pest Plant Council.
Species of Concern Fact Sheet: Hydrilla
Aquatic Nuisance Species Task Force.

Partnership

Alaska Exotic Plants Information Clearinghouse (AKEPIC): Species Biography - Hydrilla (Feb 7, 2011) (PDF | 113 KB)
University of Alaska - Anchorage. Alaska Center for Conservation Science.
See also: Non-Native Plant Species List for additional factsheets (species biographies) and species risk assessment reports of non-native species present in Alaska and also non-native species currently not recorded in Alaska (potential invasives).
Fact Sheet: Hydrilla
Massachusetts Introduced Pests Outreach Project.
Federal Noxious Weed Disseminules of the U.S. - Fact Sheet: Hydrilla verticillata
USDA. APHIS. PPQ. Center for Plant Health Science and Technology; California Department of Food and Agriculture.
Global Invasive Species Database - Hydrilla verticillata (aquatic plant)
IUCN. Species Survival Commission. Invasive Species Specialist Group.
Invaders Factsheet: Hydrilla
Ontario's Invading Species Awareness Program (Canada).
Invasive Plant Atlas of New England (IPANE) - Hydrilla
University of Georgia. Center for Invasive Species and Ecosystem Health.
Invasive Plant Atlas of the United States - Hydrilla
University of Georgia. Center for Invasive Species and Ecosystem Health.
Invasive Species Compendium - Hydrilla verticillata
CAB International.
NEANS Panel Online Guide - Hydrilla
Northeast Aquatic Nuisance Species Panel.
New York Invasive Species Information - Hydrilla

New York Invasive Species Clearinghouse.
Pacific Island Ecosystems at Risk (PIER) - Hydrilla verticillata
USDA. FS. Institute of Pacific Islands Forestry.
Plantwise Technical Factsheet - Hydrilla (Hydrilla verticillata)
CABI. Plantwise Knowledge Bank.
Texas Invasives Database - Hydrilla verticillata
TexasInvasives.org.
The Quiet Invasion: A Guide to Invasive Species of the Galveston Bay Area - Hydrilla, Waterthyme, Florida Elodea

Texas Commission on Environmental Quality, Galveston Bay Estuary Program; Houston Advanced Research Center (HARC).

Federal Government

Indian River Lagoon Species Inventory - Hydrilla verticillata
Smithsonian Institution. Smithsonian Marine Station at Fort Pierce.
National Exotic Marine and Estuarine Species Information System (NEMESIS): Chesapeake Bay Introduced Species Database - Hydrilla verticillata
Smithsonian Institution. Smithsonian Environmental Research Center. Marine Invasions Research Lab.
Nonindigenous Aquatic Species Database: Fact Sheet - Hydrilla
DOI. USGS. Wetland and Aquatic Research Center.
Provides distribution maps and collection information (State and County).
PLANTS Database - Hydrilla
USDA. NRCS. National Plant Data Center.
U.S. National Plant Germplasm System - Hydrilla verticillata
USDA. ARS. National Genetic Resources Program. GRIN-Global.

International Government

Weeds in Australia - Hydrilla verticillata
Australian Government. Department of the Environment and Energy.

State and Local Government

Class A Noxious Weed: Hydrilla
Washington State Noxious Weed Control Board.
Encycloweedia: Data Sheet - Hydrilla, Brazilian elodea, and Common elodea
California Department of Food and Agriculture.
See also: Included on California's noxious weed list; see Encycloweedia: Program Details for additional resources
Field Guide: Invasive - Hydrilla
Missouri Department of Conservation.
See also: Problem Plant Control (scroll to Invasive Plants section) for more information to help you identify and control most common invasive plants in Missouri
Invasive Plants in Pennsylvania: Hydrilla (PDF | 114 KB)
Pennsylvania Department of Conservation and Natural Resources.
See also: Invasive Plant Fact Sheets for plant species (trees, shrubs, vines, herbs and aquatic plants) that have impacted the state's natural lands
Noxious Weed Species - Hydrilla
Colorado Department of Agriculture. Conservation Services Division. Noxious Weed Program.
Weed Alerts: Hydrilla
Florida Fish and Wildlife Conservation Commission.

Academic

Factsheet: Hydrilla (PDF | 416 KB)
Pennsylvania State University. Pennsylvania Sea Grant.
See also: Aquatic Invasive Species: Resources for additional species information
Invasive Plant Fact Sheet - Hydrilla (Nov 2011) (PDF | 86 KB)
University of Pennsylvania. The Pennsylvania Flora Project of Morris Arboretum.
See also: Invasive Plant Fact Sheets for additional invasive plants in Pennsylvania
Invasive Species Guide - Hydrilla
University of Wisconsin Sea Grant.
Maine Invasive Plants Bulletin: Hydrilla
University of Maine. Cooperative Extension.
See also: Maine Invasive Plants & Entire Series for entire series of 22 fact sheets and invasive plants brochure (available in HTML/PDF or for purchase)
Plant Profile: Hydrilla Verticillata
University of Florida. IFAS. Center for Aquatic and Invasive Plants.

Professional

Maine's Interactive Field Guide to Aquatic Invaders and Their Native Look Alikes - Hydrilla
Lake Stewards of Maine.
Special Note: Formerly known as the Maine Volunteer Lake Monitoring Program.
Noxious Weed Information - Hydrilla
Colorado Weed Management Association.

Citations

  • Balciunas, J.K., M. J. Grodowitz, A.F. Cofrancesco and J.F. Shearer. 2002. Hydrilla. In: R. Van Driesche et al. (Eds.), Biological control of invasive plants in the eastern United States (FHTET-2002-04). Morgantown, West Virginia: U.S. Forest Service Forest Health Technology Enterprise Team.
  • Integrated Taxonomic Information System. Hydrilla verticillata. [Accessed Sep 10, 2014].
  • Masterson, J. 2007. Hydrilla verticillata. In: Indian River Lagoon Species Inventory. Smithsonian Marine Station.