Hydrilla

Scientific name: Hydrilla verticillata (L. f.) Royle

Common names: Hydrilla, Florida elodea, water thyme, Wasserquirl, Indian star-vine

Native To: Africa

Date of U.S. Introduction: 1960

Images: Invasive.org and Google

Video: Hydrilla Verticillata Identification -- video produced by the University of Florida-IFAS, Center for Aquatic and Invasive Plants (or click Play button below)

Means of Introduction: Aquarium trade

Impact: Crowds out native species

Current U.S. Distribution:

• National Agricultural Pest Information System - Pest Tracker - Reported Status
• 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

Federally Regulated: Federal Noxious Weed (USDA, APHIS - Noxious Weeds Program)

Management Plans: Aquatic Species

Selected Internet Resources:

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

Hydrilla verticillata - 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)

Potential Use of Insect Biocontrol Agents for Reducing the Competitive Ability of Hydrilla verticillata, ERDC/EL SR-00-1 (Feb 2000; PDF | 1.93 MB)
DOD. USACE. Engineer Research and Development Center. Environmental Laboratory.
Controls; Research

Status of Waterhyacinth/Hydrilla Infestations and Associated Biological Control Agents in Lower Rio Grande Valley Cooperating Irrigation Districts, ERDC/EL SR-00-11 (Sep 2000; PDF | 5.25 MB)
DOD. USACE. Engineer Research and Development Center.
Controls; Research

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

Hydrilla verticillata
Integrated Taxonomic Information System.
Taxonomy

Hydrilla - Plant Invaders of Mid-Atlantic Natural Areas (2002)
DOI. National Park Service and Fish and Wildlife Service.
Identification/Description; Photographs; Distribution; Introduction History; Impacts; Controls

Hydrilla Research - TEKTRAN database
USDA. Agricultural Research Service.
Research

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

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

Hydrilla - 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; Distribution; Introduction History; Impacts; Life Cycle; Habitat; Controls

Plant Profile for Hydrilla verticillata - PLANTS Database
USDA. NRCS. National Plant Data Center.
Taxonomy; Distribution; Legal Aspects

Hydrilla, Egeria, and Elodea - EncycloWeedia
California Department of Food and Agriculture.
Identification/Description; Photographs; Habitat; Distribution; Dispersion; Controls

Hydrilla Program
California Department of Food and Agriculture.
Identification/Description; Photographs; Habitat; Distribution; Dispersion; Controls

Hydrilla
Colorado Department of Agriculture. Noxious Weed Management Program.
Identification/Description; Photographs; Introduction History; Impacts; Distribution; Controls

Hydrilla - Weed Alert (PDF | 739 KB)
Florida Fish and Wildlife Conservation Commission.
Introduction History; Photographs; Illustrations; Impacts; Distribution

Hydrilla - Vermont Invasive Exotic Plant Fact Sheet (PDF | 89 KB)
Vermont Agency of Natural Resources. Environmental Conservation. Identification/Description; Illustrations; Introduction History; Impacts; Distribution; Controls

Hydrilla - Invasive Alien Plant Species of Virginia (PDF | 117 KB)
Virginia Department of Conservation and Recreation. Natural Heritage Program; Virginia Native Plant Society.
Identification/Description; Illustrations; Introduction History; Impacts; Habitat; Distribution; Controls

Hydrilla
State of Washington. King County Department of Natural Resources. Water and Land Resources Division.
Identification/Description; Illustrations; Introduction History; Dispersion; Controls

Hydrilla - Non-Native Freshwater Plants
Washington State Department of Ecology. Water Quality Program.
Identification/Description; Photographs; Illustrations; Introduction History; Impacts; Life Cycle; Habitat; Distribution; Controls

Class A Noxious Weed: Hydrilla
Washington State Noxious Weed Control Board.
Taxonomy; Identification/Description; Photographs; Impacts; Habitat; Distribution; Dispersion; Controls; Legal Aspects

Hydrilla - Invasive Plant Species of Alaska (PDF | 51 KB)
University of Alaska - Anchorage. Alaska Natural Heritage Program.
Identification/Description; Photographs; Impacts; Habitat; Controls

Hydrilla verticillata - Invasive Plant Atlas of New England (IPANE)
University of Connecticut. Ecology and Evolutionary Biology.
Taxonomy; Identification/Description; Photographs; Introduction History; Distribution; Dispersion; Controls

Hydrilla - Nonindigenous Aquatic and Selected Terrestrial Species of Florida
University of Florida. Center for Aquatic and Invasive Plants.
Photographs; Introduction History; Impacts; Distribution; Dispersion; Controls

Hydrilla verticillata "The Perfect Aquatic Weed" (Kenneth A Langeland)
University of Florida. Center for Aquatic and Invasive Plants.
Identification/Description; Photographs; Illustrations; Introduction History; Impacts; Life Cycle; Distribution; Special Note: References

Hydrilla - 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 Thyme - Exotic Aquatics of the Gulf Coast
Louisiana Sea Grant. Louisiana Marine Education Resources.
Identification/Description; Photographs; Introduction History; Impacts; Habitat; Distribution; Controls

Hydrilla verticillata - Maine Invasive Plants Bulletin no. 2527
University of Maine. Cooperative Extension.
Identification/Description; Photographs; Impacts; Habitat; Distribution; Controls

Aquatic Invaders: Hydrilla (PDF | 673 KB)
National Sea Grant College Program; Association of Zoos and Aquariums.
Photographs; Introduction History; Impacts; Life Cycle; Habitat; Distribution; Dispersion; Controls

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

Managing Hydrilla (PDF | 122 KB)
University of Nevada - Reno. Cooperative Extension.
Identification/Description; Photographs; Impacts; Habitat; Controls

Hydrilla, Aquatic Weed Fact Sheet (PDF | 158 KB)
North Carolina State University. Department of Crop Science.
Identification/Description; Photographs

Hydrilla - Biological Control of Weeds in Texas
Texas A&M University. Entomology.
Identification/Description; Introduction History; Life Cycle; Habitat; Distribution; Controls; Special Note: References

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

Hydrilla verticillata - Plant Pest Control (PDF | 58 KB)
Hawke's Bay Regional Council (New Zealand).
Identification/Description; Photographs; Impacts; Distribution; Controls

Hydrilla verticillata - Invasive Plants of California's Wildlands Book (2000)
California Invasive Plant Council.
Identification/Description; Photographs; Illustrations; Life Cycle; Habitat; Distribution; Dispersion; Controls

Hydrilla
Colorado Weed Management Association.
Identification/Description; Photographs; Life Cycle; Habitat; Distribution; Dispersion

Hydrilla verticillata
Discover Life.
Identification/Description; Photographs; Illustrations; Introduction History; Impacts; Life Cycle; Habitat; Distribution; Dispersion; Controls

Hydrilla verticillata (PDF | 60 KB)
Florida Exotic Pest Plant Council.
Identification/Description; Photographs; Impacts; Life Cycle; Habitat; Distribution

Hydrilla - Maine's Interactive Field Guide to Aquatic Invaders and Their Native Look Alikes
Maine Volunteer Lake Monitoring Program. Maine Center for Invasive Aquatic Plants.
Identification/Description; Photographs; Illustrations; Introduction History; Life Cycle; Habitat; Distribution

Hydrilla
Massachusetts Introduced Pests Outreach Project.
Identification/Description; Photographs; Impacts; Habitat

Hydrilla verticillata
Pacific Island Ecosystems at Risk.
Identification/Description; Life Cycle; Habitat; Distribution; Controls

Hydrilla verticillata
Pulling Together Initiative. Texasinvasives.org.
Taxonomy; Identification/Description; Photographs; Introduction History; Impacts; Life Cycle; Habitat; Distribution; Dispersion; Controls; Special Note: References

Hydrilla - Practical Guidebook to the Control of Invasive and Aquatic Wetland Plants of the San Francisco Bay-Delta Region
San Francisco Estuary Institute.
Identification/Description; Photographs; Impacts, Habitat; Controls

Hydrilla - Southeast Exotic Pest Plant Council Invasive Plant Manual
Southeast Exotic Pest Plant Council.
Identification/Description; Photographs; Introduction History; Habitat; Controls

Hydrilla: Invader that Chokes Waters
National Environmental Coalition on Invasive Species.
Introduction History; Photograph; Impacts; Distribution