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Identification Resources

Provides general resources to help identify unknown species that may be invasive. Species identification is important in helping gardeners, land managers, and landscape architects identify invasive species that can be harmful to local habitats. Resources are organized alphabetically by organization.

An important caveat is it can be difficult to identify species properly on the Internet. If you are unable to identify the species in question, you may want to contact your county office in the Cooperative Extension System (see Land Grant University Website Directory) and work with Extension personnel to obtain assistance from an area agent or state specialist (select state to see state pest detection contacts). Or, you may want to use the Ask an Expert feature of eXtension - Invasive Species.

See other sections for species specific information:

Busting Bugs: USDA Creates Online Tools to ID Pests (Aug 14, 2013)
USDA. Blog.
ID Tools helps agency staff to quickly identify pests, including insects, diseases, harmful weeds, and more, through an efficient, online database system. ID Tools currently includes more than 30 websites covering a vast array of pests and pests associated with specific commodities.

Identification Resources: Insects, Plants & Diseases
University of Florida. IFAS Extension. Solutions for Your Life.
Many Florida residents find unknown plants growing in their yard, unknown bugs in their houses or gardens, and apparent diseases on what were previously healthy plants. But Florida residents may not know what resources are available to identify these disease, plant, and pest organisms.



Identification Technology Program (ITP)
USDA. APHIS. PPQ. CPHST. Identification Technology Program.
ITP supports PPQ in its efforts to prevent the entry, spread, and establishment of invasive pests in the U.S. by delivering interactive, electronic identification tools.
See also: ID Aids which supports identification of plant pest of concern to PPQ. Includes over 3,000 vetted ID Aids includes both web and app-based image galleries, keys, fact sheets, screening aids, pest alerts, molecular identification tools, and more. All groups of plant pests are represented.

iMapInvasives - Invasive Species Identification Guides
Nature Conservancy. iMapInvasives.
Includes a variety of published guides and internet resources (videos) for use in identifying invasive species that are found in the participating states, provinces, and regions of the iMapInvasives network. The iMapInvasives network is currently comprised of ten U.S. states and one Canadian province (Arizona, Florida, Maine, New York, Oregon, Pennsylvania, Saskatchewan, Vermont, Virginia, and West Virginia).

Training: Species Identification
Michigan State University. Midwest Invasive Species Information Network.
The invasive species education modules will help you become more comfortable with identifying these species in the field. Includes detailed information for terrestrial plants, aquatic plants, crustaceans, fish, insects, mollusks, and pathogens. Each module includes a short ten question quiz at the end to help you assess your newly acquired knowledge.

North American Invasive Identification Guide and Checklist
Discover Life.
Provides free on-line tools to identify species, teach and study nature's wonders, report findings, build maps, process images, and contribute to and learn from a growing, interactive encyclopedia of life with 851,136 species pages and 681,390 maps.
See also: IDnature Guides

Federal Government

Identification Aids Services
USDA. Animal and Plant Health Inspection Service.
Recommended resources for those seeking identification assistance. Please note that any individual who believes they have encountered an invasive species or other quarantine significant pest, is encouraged to contact their local Cooperative Extension office for verification (see Land Grant University Website Directory)


Aquatic Invasive Species (AIS) Identification Guide (2018)
University of Minnesota. Minnesota Aquatic Invasive Species Research Center.
This ID book contains tips for identifying a number of aquatic invasive species (AIS) that are considered high-risk to Minnesota waters, as well as some common native lookalike species.

Identification Resources: Insects, Plants & Diseases
University of Florida. IFAS Extension. Solutions for Your Life.

Landscape Problem Solver
University of Maryland. Maryland Cooperative Extension.
Identifies plant pests, including insects and diseases. Includes information and instructions for submitting plant or insect samples.

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Aquatic Species

Council or Task Force

How to Identify a Mitten Crab (PDF | 198 KB)
Aquatic Nuisance Species Task Force.
See also: Education - Outreach Materials for more resources


NOBANIS - Marine Identification Key
European Network on Invasive Alien Species.
The NOBANIS identification key to marine invasive species is a Nordic project based on expert taxonomic knowledge. It is aimed at users in management of invasive species and marine biodiversity who are not trained taxonomists, but it can be useful to anyone with an interest in marine life.

Aquatic Invasive Plant Identification Guide (PDF | 320 KB)
River to River Cooperative Weed Management Area (Illinois).

Federal Government

Fragmented Phragmites: Overview and Identification of Introduced Exotic and Native Forms of Common Reed (Phragmites australis) (Jun 14, 2006; PDF | 1.73 MB)
DOI. National Park Service.
Jil Swearingen (NPS) developed the following presentation on distinguishing the native and non-native subspecies of Phragmites in the eastern U.S. (but not the Gulf Coast), drawing on information primarily from Dr. Kristin Saltonstall, now at the University of Maryland. See also: Phragmites Links for more resources

Phragmites Field Guide: Distinguishing Native and Exotic Forms of Common Reed (Phragmites australis) in the United States (Oct 2012; PDF | 1.06 MB)
USDA. Natural Resources Conservation Service.
Plant Materials Technical Note No. 56. See also: Publications Relating to Wetlands for more resources

Asian Carp Key to Identification (PDF | 113 KB)
DOI. Fish and Wildlife Service.
See also: Fisheries Program Brochures for more resources

State Government

Marine Invasive Species Identification Guide for the Puget Sound Area: Puget Sound Marine Invasive Species Volunteer Monitoring Program (MISM) (Jul 2009; PDF | 1 MB)
Puget Sound Partnership (Washington).

Michigan Invasive Species - Education & Outreach
State of Michigan.
Includes section for Identifying Invasive Species

Connecticut's Invasive Aquatic and Wetlands Plants Identification Guide (2010; PDF | 8.4 MB)
Connecticut Agricultural Experiment Station.
Bulletin No. 1027. See also: CAES Bulletins for more resources

Bay Grasses Identification Key
Maryland Department of Natural Resources.
The bay grass key was designed to allow you to identify most species of bay grasses found in Maryland.

Help with Aquatic Plant Identification
New Hampshire Department of Environmental Services.

Brief Guide to Crayfish Identification in the Pacific Northwest (2009; PDF | 440 KB)
Washington Department of Fish & Wildlife.
See also: Fishing - Crayfish for more resources

Aquatic Weed Identification
King County Department of Natural Resources (Washington). Water and Land Resources Division.

Also see Aquatic Weed Identification Flow Chart (PDF | 234 KB)


Wisconsin Fish Identification
University of Wisconsin Center of Limnology; Wisconsin Sea Grant; Wisconsin Department of Natural Resources.

A Field Guide to Invasive Plants of Aquatic and Wetland Habitats for Michigan (2010)
Michigan State University Extension.

AQUAPLANT: Plant Identification
Texas A&M University. AgriLife Extension Service. Department of Wildlife and Fisheries Sciences.
As a pond manager diagnostic tool, "AQUAPLANT is designed to help you identify aquatic plants using photos, drawings, and descriptions. Using this section involves viewing photos and drawings of aquatic plants until you identify the plant in question."


Marine Introduced Species Monitoring Resource Center - Species Identification
Salem Sound Coastwatch.
Also see - New England Marine Invaders Identification and Potential Marine Invaders Identification

Practical Guidebook for the Identification and Control of Invasive Aquatic and Wetland Plants of the San Francisco Bay-Delta Region (Apr 2003)
San Francisco Estuary Institute.
Identify serious plant invasions in aquatic and wetland habitats of the San Francisco Bay-Delta and watershed. Plants included are considered by Bay-Delta invasive plant experts to represent some of the most significant threats to Bay and Delta waterways and wetlands. This guidebook's goal is to provide you with information to take action against non-native plant invasions. Early detection of invasions can save vast amounts of labor and money. The guidebook can be downloaded and printed in various formats.

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Hawaii's Invasive Plant Species: A Noxious Weed Identification Key
Bishop Museum. Hawaii Biological Survey.

Leafsnap: An Electronic Field Guide
Columbia University; University of Maryland; Smithsonian Institution.
Tree identification mobile app using visual recognition software to help identify tree species from photographs on their leaves.

Federal Government

PLANTS Interactive ID Keys
USDA. Natural Resources Conservation Service. National Plant Data Center.

Plant Identification Tools and Guides
USDA. Natural Resources Conservation Service.

Invasive Species Identification Sheets
USDA. Natural Resources Conservation Service. Connecticut.
The Connecticut NRCS produced Invasive Species Fact Sheets, which contain identification information and a selection of photographs for each species.

A Field Guide for the Identification of Invasive Plants in Southern Forests (2010) / Web Version
USDA. Forest Service. Southern Research Station.
Gen. Tech. Rep. SRS-119; previous version - Nonnative Invasive Plants of Southern Forests: A Field Guide for Identification and Control (2003).

International Government

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

State Government

Identify a Noxious Weed
Washington State Noxious Weed Control Board.

King County (Washington) Noxious Weed Control Program - Weed Identification Help
King County Department of Natural Resources (Washington). Water and Land Resources Division.


Identification Key to Weeds
University of California. Statewide Integrated Pest Management Program.

Weed Research and Information Center - Weed Identification Tool
University of California. Cooperative Extension and Agricultural Experiment Station.

Plant Recognition Cards
University of Florida. IFAS. Center for Aquatic and Invasive Plants.
Includes individual recognition cards available online (can purchase set) by common name and scientific name.
See also: Plant ID Videos.

Identification & Biology of Non-Native Plants in Florida's Natural Areas
University of Florida. IFAS. Center for Aquatic and Invasive Plants.
Langeland, K.A.; Burks, K.C., ed. 1998. Identification & biology of non-native plants in Florida's natural areas. Gainesville, FL: University of Florida. 165 p.
This field guide (first edition), intended as a tool for land managers, covers 62 non-native plant species considered weeds in Florida's natural areas. With descriptions and photographs, the guide provides identification characters of these plants, plus details on their ecological significance, distribution, and life history. The second edition is not currently available online, but may be purchased.
Note: See alternative online version (Florida Exotic Pest Plant Council), by type of species and by individual species.

Weed Science - Weed Identification
University of Illinois at Urbana-Champaign.

Identifying Weeds in Field Crops
Michigan State University. Integrated Pest Management Program.

MSU Turf Weeds.net - Weed ID Tool
Michigan State University. Department of Crop and Soil Sciences.

Weed Identification & Management - Weed Identification Tool
University of Wisconsin.
"The database contains 280 of the most common weeds/invasive plants found in agricultural, urban, and natural settings in Wisconsin. The database is organized to ask questions about the unknown plant, and, based on the user's input, the website will produce a list of plants (scientific and common names) along with thumbnail images that match the information entered."

Identification and Control of Invasive and Troublesome Weeds in North Dakota
North Dakota State University. Extension Service.
A publication to help land managers properly identify and control noxious and invasive weeds found in the state (Publication W1411; reviewed and reprinted May 2015).

Field Guide To The Identification of Japanese Stiltgrass (Dec 2012)
Alabama Cooperative Extension System.
This publication provides descriptions and clear pictures of key characteristics as well as details on how to distinguish several common look-a-like species.

Ohio Perennial & Biennial Weed Guide
Ohio State University. Ohio Agricultural Research and Development Center.
Includes a photo key intended to help the casual user identify a weed. Weeds that look similar are grouped together.

Turf & Weed Identification
North Carolina State University. Center for Turfgrass Environmental Research & Education.

Ask Mr. Smarty Plants
University of Texas at Austin. Lady Bird Johnson Wildflower Center.

Virginia Tech Weed Identification Guide
Virginia Polytechnic Institute and State University. Plant Pathology, Physiology, and Weed Science.
Aides in the identification of common weeds and weed seedlings found throughout Virginia and the Southeastern U.S.


What Tree Is That? Tree Identification Field Guide
Arbor Day Foundation.

Weed Identification Tool
Colorado Weed Management Association.

Plant Finder
Missouri Botanical Garden.
"The Kemper Garden Center at the Missouri Botanical Garden has pictures, plant information, and sources for many natives that are in the horticultural trade. You can search by scientific or common name. Through their PlantFinder Search options you can also search by preferred habitat, growth form, use (water plant, attracts butterflies, dried flowers, etc), and other characteristics, like good fall color."

Mistaken Identity? Invasive Plants and their Native Look-alikes: an Identification Guide for the Mid-Atlantic (Nov 2008; PDF | 7 MB)
New York Botanical Garden.
Published by the Delaware Department of Agriculture in collaboration with Claude E. Phillips Herbarium at Delaware. State University and Delaware Center for Horticulture
"This publication is a full-color, 62-page booklet. The purpose of the work is to facilitate correct identification of confusingly similar invasive and native plant species. Targeted at land managers, gardeners, conservationists, and all others interested in plants, this booklet covers over 20 invasive species and their native look-alikes."

Weed Identification
Weed Science Society of America.

Buffelgrass Identification Guide
Arizona-Sonora Desert Museum.
Provides high-quality, high-resolution pictures of buffelgrass at various life stages and various settings and key characteristics for identifying buffelgrass.

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Wildlife Damage Inspection Process
Internet Center for Wildlife Damage Management.

Antkey - ID Guide for Introduced Ants
USDA. APHIS. PPQ. Identification Technology Program.
Antkey is a community resource for the identification of invasive, introduced and commonly intercepted ant species from across the globe. Developed through collaboration between USDA's Center for Plant Health Science and Technology (CPHST) and the University of Illinois, Antkey focuses on over 115 ant species that are introduced, invasive or commonly intercepted in the U.S. including Hawaii. Antkey seeks to mitigate the spread of established introduced ants and prevent the incursion of new introductions by providing quarantine personnel, inspectors and conservation biologists with a user-friendly identification tool specifically designed for non-specialists. Antkey is the second in a series of digital ant identification tools specifically designed and developed for non-specialists. The first tool, PIAkey: Pacific Invasive Ant Key was released in 2008.

PIAKey - Invasive Ants of the Pacific Islands
USDA. APHIS. PPQ. Identification Technology Program.
The Pacific Invasive Ant Key (PIAkey) is an illustrated identification guide designed to assist users identify the most common and dangerous invasive ant species threatening the ecosystems, economies and people of the Pacific Island region.

Terrestrial Mollusc Tool
USDA. APHIS. PPQ. Identification Technology Program.
The Terrestrial Mollusc Tool was specifically designed to assist in the identification of adult terrestrial slugs and snails of agricultural importance. The tool also includes species of quarantine significance as well as invasive and contaminant mollusc species commonly intercepted at U.S. ports of entry. This Lucid-based identification tool specifically targets federal, state and other agencies or organizations within the U.S. that are concerned with the detection and identification of molluscs of significance. This tool includes 33 families and 128 species. This resource also includes an interactive identification key, comparison chart, fact sheets, biological and ecological notes, a dissection tutorial, a glossary of commonly used terms, and a list of useful links and references.

Federal Government

Bug Bytes
USDA. Agricultural Research Service.
Includes sound files of various insects (including invasive insects as well as links to pictures or other information about each species).

Insect & Mite Identification Service
USDA. ARS. Systematic Entomology Laboratory.
The Systematic Entomology Laboratory (SEL) routinely provides specimen identification assistance as a free service to both governmental and private entities, including federal research and regulatory agencies, state departments of health and agriculture, university researchers, and private citizens.

State Government

Pest Alert: Giant African Land Snail And Giant South American Snails: Field Recognition (Feb 2010; PDF | 1.22 MB)
Florida Department of Agriculture and Consumer Services. Plant Industry.
See also: Giant African Land Snail for more resources


Amphibian and Reptile Identification
University of Florida. Department of Wildlife Ecology and Conservation.

Insect Advice from Extension
Pennsylvania State University. College of Agricultural Sciences. Entomology.
Provides fact sheets and identification service information.

Identify Your Pest
Oregon State University. National Pesticide Information Center.


Arthropod Identification
American Museum of Natural History.

Light Brown Apple Moth Screening Aid

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Federal Government

Citrus Canker: Identification in the Field and in the Laboratory (Mar 2001; PDF | 46 KB)
U.S. Agency for International Development.
Prepared for: U.S. Agency for International Development under AID Contract No. 511-C-00-99-00114-00

International Government

Aquatic Animal Diseases Significant to Australia: Identification Field Guide, 4th Edition (2012)
Australian Government. Department of Agriculture and Water Resources.

Produced by: Australian Department of Agriculture, Fisheries, and Forestry

Common Tree Diseases of British Columbia
Natural Resources Canada. Pacific Forestry Centre.


CMG GardenNotes - Diagnosing Tree Disorders
Colorado State University. Extension. Colorado Master Gardener Program.

Plant Disease Diagnostic Clinic
Cornell University.

Plant Disease Clinic
University of Minnesota. Department of Plant Pathology.

Plant Disease Diagnostics Clinic
University of Wisconsin-Madison. Department of Plant Pathology.
The University of Wisconsin-Madison/Extension Plant Disease Diagnostics Clinic (PDDC) provides assistance in identifying plant diseases and provides educational information on plant diseases and their control.

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Last Modified: Sep 22, 2018
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