Worst Weeds

Integrated plant management, plant toxicity, effects on livestock from Texas A&M

Fact sheet from the Colorado Weed Management Assoc.

Low-Impact, Selective Herbicide Application for Control of African Rue from USDA Forest Service

Toxicity and management information from the Texas Toxic Plant Database

Arundo (Arundo donax)

Management considerations from the USFS Fire Effects Information System

Management information (scroll down) from invasivespecies.gov

Management information and links from the Global Invasive Species Database

Policy Statement, Florida Native Plant Society. "The Florida Native Plant Society opposes the agricultural production of Arundo donax . . . as a biofuel in Florida due to its invasive characteristics and empirical evidence of impact on native plant communities. The Society further encourages the eradication of existing stands of this species and the banning of its sale as an ornamental to prevent invasion of native plant habitats in Florida."

Species Management Summary from The Nature Conservancy's Invasives on the Web

Team Arundo del Norte. Focus on Central and Northern California; many good links.

Bermudagrass (Cynodon dactylon)

Biology and management from University of California IPM Online.

Comprehensive database including biogeographic associations, management, and fire ecology from the USDA Forest Service Fire Effects Information System

Black henbane (Hyoscyamus niger)

Biology and Management from Colorado State University Extension; includes herbicide recommendations

Black henbane from Alberta Invasive Plants; good illustrations

Comprehensive info from Colorado Weed Management Association

Fact sheet from the California Department of Food and Agriculture’s Encycloweedia website

Managing black henbane from University of Nevada-Reno Cooperative Extension

Brazilian elodea (Egeria) (Egeria densa)

General and technical management information from the Washington Dept. of Ecology Non-Native Freshwater Plants program.

Many links to identification, control, and more information, from invasivespecies.gov

Buffalobur (Solanum rostratum)

Brief description and images from Oklahoma Cooperative Extension Service

Complete description and references from the Washington State Noxious Weed Control Board

Photos and description on one-page factsheet from Purdue Extension

Buffelgrass (Pennisetum ciliaris)

Fact sheet covering distribution and management; includes link and contact information from the Global Invasive Species Database

Fact sheet and report on threat to Ironwood Forest National Monument from the Arizona-Sonora Desert Museum

Fact sheets available through the Sonoran Desert Conservation Plan

Links to fact sheet and control information from the Nature Conservancy’s Invasives on the Web

Camelthorn (Alhagi pseudalhagi syn. Alhagi maurorum Medik. and Alhagi camelorum Fisch. )

Fact sheet from AZ Dept of Transportation

General information, control and images from WA Noxious Weed Control Board

Canada thistle (Cirsium arvense)

Biological control of Canada thistle from Invasive.org

Comprehensive management info from Colorado State University Cooperative Extension

Fact sheet from Invasives on the Web

Fact sheet from Plant Conservation Alliance

Identification, control, and photos of all stages from Oregon State University Weed Management in Nursery Crops

Cheatgrass (downy brome; Bromus tectorum)

Challenging Cheatgrass, 6 page color-illustrated pdf from USFS, Rocky Mtn Research Station, with recent research on control, April 2008.

Cheatgrass management from Utah State University Extension Range Plants of Utah.

Homeowner's Guide to Cheatgrass, from University of Nevada-Reno Cooperative Extension Photos and info on fire hazard and all types of control strategies.

Species Management Summary from The Nature Conservancy. Good photos.

What about cheatgrass? from Partnership for Arid Lands Stewardship education and research initiative. Describes cheatgrass ecology and advantage over native plants.

Common burdock (Arctium minus)

Common Burdock from WeedScience at University of Wisconsin. Comprehensive description with references, no photos

Common Burdock from Saskatchewan Invasive Species Project. Description and photos, with links to herbicide recommendations in 2006 Crop Protection Guide from Saskatchewan Dept. of Ag

A Guide to Weeds in British Columbia: Common Burdock (pdf), a profile from Weeds BC (British Columbia Ministry of Agriculture and Food)

Identification and biology from University of Wisconsin Weed Science

Common crupina (Crupina vulgaris)

Biology of common crupina and yellow starthistle, two Mediterranean winter annual invaders in Western North America, review article from Weed Science 49:439-447, 2001. View as html or pdf

Fact sheet from California Department of Food and Agriculture’s Encycloweedia website

A Guide to Weeds in British Columbia: Common Crupina (pdf), a profile from Weeds BC (British Columbia Ministry of Agriculture and Food)

Managing Common Crupina (pdf) from University of Nevada-Reno Cooperative Extension

Common tansy (Tanacetum vulgare)

Fact sheet from Stevens County (WA) Noxious Weed Control Board.

A Guide to Weeds in British Columbia: Common Tansy (pdf), a profile from Weeds BC (British Columbia Ministry of Agriculture and Food)

Identification, control, and photos of all stages from Oregon State University Weed Management in Nursery Crops

MontGuide fact sheet from Montana State University Extension. View as html or pdf

Dalmatian toadflax (Linaria dalmatica)

Biological control of Dalmatian toadflax and yellow toadflax from the Cornell University Biological Control site

Species Management Summary and Images from The Nature Conservancy's Global Species Initiative

Weed Watch from MSU Extension. Full-color, well-illustrated flyer overs identification, biology and habitat, and control.

Wicked Weed of the West — a discussion with Extension weed scientists from U of Idaho and U of Wyoming

Diffuse knapweed (Centaurea diffusa)

Biological Control Plan from Colorado Dept. of Agriculture

The Centaurea Pages — A comprehensive site covering the genus Centaurea as a whole, including North American knapweeds, ornamental knapweeds, taxonomic data, and an image gallery of beautiful 19th Century botanical illustrations.

Fact sheet from Colorado State University Cooperative Extension

Knapweed Identification and Control: Four Common Knapweeds found in Oregon From OSU Extension. Spotted, Russian, and diffuse knapweed, and yellow starthistle. Excellent photos comparing species.

Dyer's woad (Isatis tinctoria)

Description and control from WA Noxious Weed Control Board

Dyer's woad: A threat to rangeland in Montana — from MSU Extension

Integrated Management info from Summit Co, Utah

Eurasian watermilfoil (Myriophyllum spicatum)

General and technical management information from the Washington Dept. of Ecology Non-Native Freshwater Plants program.

IECWMA-CIPM Web-Based Eurasian Watermilfoil Control Process. Site created by Inland Empire Cooperative Weed Management Area, funded by CIPM. Includes an interactive mapping page and a decision-making matrix.

Management information and links from the Global Invasive Species Database

Many links to identification, control, and more information, from invasivespecies.gov.

Field bindweed(Convolvulus arvensis)

Annotated Bibliography on the Ecology and Management of Invasive Species:
Field bindweed (Convolvulus arvensis L.). Prepared for the Garry Oak Ecosystems Recovery Team and the Nature Conservancy of Canada, May 2005.

Biology and management Pest Note from University of California IPM Online. Scroll down to find pdf file.

Comprehensive database including biogeographic associations, management, and fire ecology from the USDA Forest Service Fire Effects Information System

Fact sheet from Ontario Ministry of Agriculture and Food

Identification and control from North Dakota State University

Identification, control, and photos of all stages from Oregon State University Weed Management in Nursery Crops

Plant biology, management and current research from Michigan State University

Garlic Mustard (Alliaria petiolata)

Description and control from the Washington State Noxious Weed Control Board

Ecology, distribution and management from the National Park Service’s Weeds Gone Wild site

Summary from The Nature Conservancy’s Invasives on the Web

Giant salvinia (Salvinia molesta)

Comprehensive info from USGS; many links

Comprehensive info from PIER (Pacific Island Ecosystems at Risk)

Many links to identification, control, and more information, from invasivespecies.gov

Many links from invasive.org.

Weed Alert from The Nature Conservancy

Hawkweeds (Hieracum pratense syn. Hieracium caespitosum)

Detailed fact sheet with info on BMPs from the King County Noxious Weed Control Program

General info and control of orange hawkweed and yellow hawkweed from WA Noxious Weed Control Board

Hawkweed identification key for the Pacific Northwest, developed by Linda Wilson of the University of Idaho and published by the BC Ministry of Forest and Range.

Hawkweeds. Comprehensive University of Idaho website devoted to hawkweeds in the Western U.S. and Canada.

Images from Invasives.org

Montguide fact sheet from the MSU Extension Service

Summary from the Idaho One plan

Himalayan Blackberry (Rubus discolor)

Fact sheet from the BLM Redding, CA office

Fact sheet from Sequoia and Kings Canyon National Parks, NPS Invasive non-native plants page

Fact sheet from the Lake Friendly Gardening Guide in Whatcom Co., WA

Links to fact sheet and control information from the Nature Conservancy’s Invasives on the Web

Hoary cress (Cardaria spp.)

Hoary Cress Consortium— a scientific group exploring the biological control, ecology, and systematics of hoary cress. Biological control info update, May 2003

IWM of Hoary cress from Douglas County, Nevada

Horsenettle (Carolina horsenettle) (Solanum carolinense)

Identification and control of horsenettle in Virginia from Virginia Tech

Managing Silverleaf and Carolina Horsenettles (pdf) from University of Nevada-Reno Cooperative Extension

NAPPO Pest Fact Sheet Solanum carolinense L. Distribution, economic impact, control methods, bibliography

Threat to livestock and control with herbicides from Texas Toxic Plant Database (Texas A&M)

Houndstongue (Cynoglossum officinale)

Comprehensive database including biogeographic associations, management, and fire ecology from the USDA Forest Service Fire Effects Information System

Description and management from the Washington State Noxious Weed Control Board

Houndstongue Weed Watch from MSU Extension. Full-color pdf flyer with I.D., biology, and control info. Download or contact MSU Extension Publications for free copies.

Managing Houndstongue (pdf) from University of Nevada-Reno Cooperative Extension

Montguide fact sheet from Montana State University Extension. View as html or pdf

Hydrilla (Hydrilla verticillata)

General and technical management information from the Washington Dept. of Ecology Non-Native Freshwater Plants program.

Management information and links from the Global Invasive Species Database

Many links to identification, control, and more information (scroll down), from invasivespecies.gov

Species Management Summary from the Nature Conservancy

**Japanese Knotweed (Polygonum cuspidatum)**

Ecology, distribution, and management from the National Park Service’s Weeds Gone Wild site

Japanese Knotweed General info from King County (Seattle, WA) Noxious Weed Control Program, including link to PowerPoint slide show that can be downloaded.

Knotweed biology and control pdf file from King County (Seattle, WA) Noxious Weed Control Program

Summary from the Nature Conservancy’s Invasives on the Web

Western Society of Weed Science 2007 Knotweed Symposium. Proceedings cover case histories as well as research; broad range of information; excellent photos.

Johnsongrass (Sorghum halepense)

Comprehensive database including biogeographic associations, management, and fire ecology from the USDA Forest Service Fire Effects Information System

Description and management practices from the Washington State Noxious Weed Control Board

Fact sheet from the California Department of Food and Agriculture’s EncycloWeedia website

Johnsongrass and Shattercane control: An Integrated Approach (pdf) from the Pennsylvania State University Cooperative Extension

Jointed goatgrass (Aegilops cylindrica)

Biology and management (pdf) from Pacific Northwest Extension Publications (Idaho, Oregon, Washington)

Biology and management from Montana State University-Bozeman

Controlling Jointed Goatgrass from University of Nebraska-Lincoln

Description and management practices from the Washington State Noxious Weed Control Board

Fact sheet from California Department of Food and Agriculture’s EncycloWeedia website

National Jointed Goatgrass Research Program website containing a host of information about jointed goatgrass

Leafy spurge (Euphorbia esula)

Biologically based IPM from Team Leafy Spurge

Fact sheet from Plant Conservation Alliance

Management and control from CA Encycloweedia

Profile from USDA Plants Database

Leafy spurge Weed Watch from MSU Extension. Full-color pdf flyer with I.D., biology, and control info. Download or contact MSU Extension Publications for free copies.

Lehmann Lovegrass (Eragrostis lehmanniana>)

Changing Grasslands: Interactions between native and non-native vegetation. Arizona AES Research Report, 1999.

Fires Don't Hinder Lovegrass at Buenos Aires Refuge: Research results from University of Arizona

Photos from the Saguaro Juniper Corporation

Malta starthistle (tocalote; Centaurea melitensis)

General information from the Arizona Cooperative Extension

Toxicity and management information from the Texas Toxic Plant Database

Yellow starthistle fact sheet from UC Cooperative Extension covers Malta starthistle

Matgrass (Nardus stricta)

Brief description from Idaho One Plan website

Matgrass species info from BLM weedmapper.org

Matgrass control from Twin Falls County (ID) Weeds

Meadow knapweed (Centaurea pratensis)

Biology and Biocontrol of Knapweed. Comprehensive publication from Forest Service. I.D. and key for all knapweeds, distribution maps, biology and application of biocontrol insects, good illustrations.

Description and control from King County (WA) Dept. of Natural Resources and Parks

Identification, biology, control (pdf) Fact Sheet from Pacific Northwest Extension Publications (Idaho, Oregon, Washington). Excellent photos and drawings.

Meadow Knapweed from Whatcom Weeds. Excellent photos but no control info.

Russian and Meadow Knapweed from Wallowa County (OR) Weed Watch. Info on control with herbicide.

Mediterranean Sage (Salvia aethiopis)

Fact Sheet from Colorado Dept. of Agriculture

General information including control info from the Washington State Noxious Weed Control Board

Medusahead (Taeniatherum caput-medusae)

Brief description from Idaho One Plan website

Comprehensive database including biogeographic associations, management, and fire ecology from the USDA Forest Service Fire Effects Information System

Fact sheet from the California Department of Food and Agriculture’s Encycloweedia website

Medusahead: Economic Impact and Control in Nevada UNR CES Fact Sheet FS-02-37

Musk thistle (Carduus nutans)

Biology and management from Colorado State University Cooperative Extension. View as html or pdf

Comprehensive database including biogeographic associations, management, and fire ecology from the USDA Forest Service Fire Effects Information System

Description and control from the University of Nebraska-Lincoln

Fact sheet from Plant Conservation Alliance’s Alien Plant Working Group

Map of reported distribution (GIF) in the United States from the National Agricultural Pest Information System

Orange hawkweed (Hieracium aurantiacum)

Best Management Practices (pdf) for the hawkweeds from King County (WA) Department of Natural Resources and Parks

Biology and management (pdf) of the hawkweeds from Pacific Northwest Extension Publications (Idaho, Oregon, Washington)

Description and management practices from the Washington State Noxious Weed Control Board

Hawkweeds. Comprehensive University of Idaho website devoted to hawkweeds in the Western U.S. and Canada.

Montguide fact sheet from Montana State University Extension. View as html or pdf

Weed Management factsheet (pdf) from British Columbia Ministry of Agriculture, Food, and Fisheries

Oxeye daisy (Chrysanthemum leucanthemum)

Annotated Bibliography on the Ecology and Management of Invasive Species: Oxeye daisy (Leucanthemum vulgare Lam.) (synonym Chrysanthemum leucanthemum L.).
Prepared for the Garry Oak Ecosystems Recovery Team and the Nature Conservancy of Canada, May 2005.

Fact sheet from Stevens County Weed Control Board, WA

Management from CA Encycloweedia

MontGuide fact sheet from the Montana State University Extension Service

Oxeye daisy from WA Noxious Weed Control Board

Perennial pepperweed (Lepidium latifolium)

Biology, Ecology, and Control of Perennial Pepperweed from UC Extension WeedRIC

Control of Perennial Pepperweed from WeedRIC

Ecology and Control of Perennial Pepperweed from CA Exotic Plant Pest Council 1995 Symposium Proceedings

Perennial Pepperweed in Southern Nevada, (pdf) from UNR Cooperative Extension. Includes info on grazing and biocontrol

Perennial sowthistle (Sonchus arvensis)

Comprehensive database including biogeographic associations, management, and fire ecology from the USDA Forest Service Fire Effects Information System

Description and management practices from the Washington State Noxious Weed Control Board

Managing Perennial Sowthistle (pdf) from University of Nevada-Reno Cooperative Extension

Species abstracts of highly disruptive exotic plants at Pipestone National Monument: Sonchus arvensis from the USGS Northern Prairie Wildlife Research Center

Phragmites (Common reed; Phragmites australis)

Fragmented Phragmites: Overview and Identification of Introduced Exotic and Native Forms of Common Reed (Phragmites australis). Prepared by Jil M Swearingen, National Park Service June 14, 2006.

General information including links to images from Washington State Noxious Weed Control Board

Overview and Identification of Introduced Exotic and Native Forms of Common Reed (Phragmites australis). PDF of a PowerPoint from PCA's Alien Plant Working Group. Excellent detailed photos for identification.

Phragmites: Common Reed from invasiveplants.net. Comprehensive site covering all aspects of ecology, control, resarch, and more. Includes free Phragmites Diagnostic Service to determine whether a particular stand/clone is a native or introduced haplotype.

Summary from The Nature Conservancy’s Invasive on the Web

Plumeless thistle (Carduus acanthoides)

Biology and control from Wisconsin Department of Natural Resources

Fact sheet from California Department of Food and Agriculture’s EncycloWeedia website

Guide to Weeds in British Columbia: Plumeless Thistle (pdf), a profile from Weeds BC (British Columbia Ministry of Agriculture and Food)

Map of reported distribution (GIF) in the United States from the National Agricultural Pest Information System

Perennial and Biennial Thistle Control from North Dakota State University Extension Service. View as html or pdf

Poison hemlock (Conium maculatum)

Fact sheet (pdf) from San Francisco Peaks Weed Management Area, Coconino National Forest. Fact sheet from Channel Islands National Park. See additional links on the SWEPIC site.

A Guide to Weeds in British Columbia: Poison Hemlock (pdf), a profile from Weeds BC (British Columbia Ministry of Agriculture and Food)

Impacts on livestock (scroll down ) from the USDA Agricultural Research Service Poisonous Plant Research Laboratory

MontGuide fact sheet from Montana State University Extension. View as html or pdf

Puncturevine (Tribulus terrestris)

Description and management practices from the Washington State Noxious Weed Control Board

Fact sheet from California Department of Food and Agriculture’s EncycloWeedia website

A Guide to Weeds in British Columbia: Puncturevine (pdf), a profile from Weeds BC (British Columbia Ministry of Agriculture and Food)

Identification and Management of Puncturevine (pdf) from University of Nevada-Reno Cooperative Extension

Map of reported distribution (GIF) in the United States from the National Agricultural Pest Information System

Purple loosestrife (Lythrum salicaria)

Fact sheet from Greener Roadsides, a publication of the Federal Highway Administration

Fact sheet from Plant Conservation Alliance

PLS Purple Loosestrife Project from CA Dept. of Food & Agriculture—comprehensive site.

Purple Loosestrife InfoCentre, from Manitoba Purple Loosestrife Project

Purple loosestrife, from Ecology and Management of Invasive Plants Program at Cornell University

Purple Pages — web site of the Purple Loosestrife Project at Michigan State University, initiated in January 1997 to couple biological control of purple loosestrife with an innovative outreach and education program.

Quackgrass (Agropyron repens or Elytrigia repens)

A Guide to Weeds in British Columbia: Quackgrass (pdf), a profile from Weeds BC (British Columbia Ministry of Agriculture and Food)

Quackgrass and It’s Control from Iowa State University Extension

Brief fact sheet on managing quackgrass in lawns and gardens from Montana State University

Comprehensive database including biogeographic associations, management, and fire ecology from the USDA Forest Service Fire Effects Information System

Rush skeletonweed (Chondrilla juncea)

Collection and Redistribution of Biological Control Agents of Rush Skeletonweed (pdf) paper from University of Idaho Cooperative Extension

A Guide to Weeds in British Columbia: Rush Skeletonweed (pdf), a profile from Weeds BC (British Columbia Ministry of Agriculture and Food)

Map of reported distribution (GIF) in the United States from the National Agricultural Pest Information System

Weed Alert factsheet from British Columbia Ministry of Agriculture, Food, and Fisheries. View as html or pdf

Russian knapweed (Acroptilon repens syn. Centaurea repens)

Identification, biology, and management from Colorado State University Cooperative Extension. View as html or pdf

Know Your Knapweeds, photo comparisons of spotted, diffuse, and Russian knapweed; control measures for each, from North Dakota State University Extension Service. View as html or pdf

Map of reported distribution (GIF) in the US from the National Agricultural Pest Information System

Montana Knapweeds: Identification, Biology, and Management bulletin from Montana State University Extension Service (includes spotted knapweed, diffuse knapweed, squarrose knapweed, yellow starthistle, and Russian knapweed). View as html

**Russian Olive (Eleagnus angustifolia)**

Brief description of the ecology, distribution, and management from the National Park Service’s Weeds Gone Wild page

History, biology, suppression, and revegetation of Russian-olive sites, USDA/NRCS Tech Report. Includes species recommendations for revegetation. From Southwest Exotic Plant Information Clearinghouse (SWEPIC)

Summary from the Nature Conservancy’s Invasives on the Web page

Species profile from the National Agricultural Library with many links

Vegetation Management Guidelines from the Illinois Natural History Survey

Saharan mustard (Brassica tournefortii)

Fact sheet from the Global Invasive Species Database

Fact sheet and images from the Arizona-Sonora Desert Museum

Images and information from the Nature Conservancy’s Invasives on the Web

Links from the Southwest Exotic Plant Information Clearinghouse

Saltcedar complex (Tamarisk) (Tamarix spp.)

The March 2008 issue of Restoration Ecology has a special section on Tamarix restoration from papers presented at the 2006 Tamarisk Research Conference. Scroll down at:http://www.blackwell-synergy.com/toc/rec/16/1 for pp 90-190, "Restoration in the context of Tamarix spp. invasion and control along rivers in western North America."

Beneficial Beetles Take a Bite out of Saltcedar, in April, 2005, issue of USDA Agricultural Research magazine

Controlling tamarisk General info and recommended approach from The Nature Conservancy

Fact sheet from Plant Conservation Alliance

Ecological Impacts of Exotic Invasive Species — discusses saltcedar in particular

Identify, report, control (pdf) from ND Dept. of Agriculture

Tamarisk control from a Practical Guidebook to Control of Aquatic and Invasive Plants of the San Francisco Bay-Delta Region

Saltcedar — MontGuide fact sheet from the Montana State University Extension Service

2006 Tamarisk Research Conference: Current Status and Future Directions. Multiple univerisity, agency, and industry sponsors. Abstracts, presentation, posters, summaries on website.

Team Tamarisk: Cooperating for Results. 2004 Conference Proceedings. Sponsored by USDA, DOI, the National Invasive Species Council, and 14 other organizations.

Weed Watch from MSU Extension. Full-color pdf flyer with I.D., biology, and control info. Download or contact MSU Extension Publications for free copies.

Scentless chamomile (Matricaria perforata, Matricaria maritima, or Tripleurospermum perforata)

A Guide to Weeds in British Columbia: Scentless Chamomile (pdf), a profile from Weeds BC (British Columbia Ministry of Agriculture and Food)

Biology and management from Saskatchewan Ministry of Agriculture, Food, and Rural Revitalization

Scotch broom (Cytisus scoparius)

Annotated Bibliography on the Ecology and Management of Invasive Species: Scotch broom (Cytisus scoparius). Prepared for the Garry Oak Ecosystems Recovery Team and the Nature Conservancy of Canada, May 2005.

Controlling Scotch (Scots) broom in the Pacific Northwest — Best Management Practices from the Nature Conservancy (pdf). Thirteen pages with excellent photos.

Scotch Broom (pdf) Fact sheet from Pacific Northwest Extension Publications

Scotch Broom in British Columbia from Canadian Forest Service

Scotch thistle (Onopordum acanthium)

Description and management from University of Idaho Extension

Integrated Weed Management of Scotch Thistle by Douglas County (CO) Cooperative Extension

Managing Scotch Thistle (pdf) from University of Nevada-Reno Cooperative Extension

Maps of reported distribution (GIF) in the United States from the National Agricultural Pest Information System

Scotch thistle from the Washington State Noxious Weed Control Board

Sericea lespedeza (Lespedeza cuneata)

Comprehensive database including biogeographic associations, management, and fire ecology from the USDA Forest Service Fire Effects Information System

Ecology and Management of Sericea Lespedeza by Oklahoma State University Cooperative Extension Service (scroll down through list of PDF files)

PCA Alien Plant Working Group: Smooth Cordgrass Fact Sheet

Fact sheet from the Plant Conservation Alliance Alien Plant Working Group

Fact sheet from the Southeast Exotic Plant Pest Council Invasive Plant Manual

Sericea Lespedeza: History, Characteristics, and Identification (pdf) from Kansas State University Agricultural Experiment Station and Cooperative Extension

Silverleaf nightshade (Solanum elaeagnifolium)

Fact sheet from CA EncycloWeedia

Managing Silverleaf and Carolina Horsenettles (pdf) from University of Nevada-Reno Cooperative Extension

Silverleaf nightshade. Discription, biology, control from the Washington State Noxious Weed Control Board

Skeletonleaf bursage (Ambrosia tomentosa)

Brief description from Idaho One Plan website

Plant Profile from PLANTS Database

Skeletonleaf Bursage, in Idaho's Noxious Weeds (pdf file). Pictures of rosettes and seedlings, habitat, and updated distribution maps

Spartina (Smooth Cordgrass) (Spartina alterniflora)

Friends of Willapa National Wildlife Refuge (WA)

Spartina — Whatcom County (WA) Noxious Weed Control Board

USDA/NRCS Plant Profile — smooth cordgrass

Spotted knapweed (Centaurea maculosa)

Fact sheet from Colorado State University Cooperative Extension

Fact sheet from Plant Conservation Alliance

Knapweed Identification and Control: Four Common Knapweeds found in Oregon From OSU Extension. Spotted, Russian, and diffuse knapweed, and yellow starthistle. Excellent photos comparing species.

Weed Watch from MSU Extension. Full-color pdf flyer with I.D., biology, and control info. Download or contact MSU Extension Publications for free copies.

Squarrose knapweed (Centaurea vigata, Centaurea squarrosa, or Centaurea triumfettii)

A Guide to Weeds in British Columbia: Squarrose Knapweed (pdf), a profile from Weeds BC (British Columbia Ministry of Agriculture and Food)

Biological Control Agents for Utah Weeds: Knapweed Seedhead Gall Flies Fact Sheet from Utah State University Extension.

Knapweed fact sheet (pdf) from San Francisco Peaks Weed Management Area, Coconino National Forest. Found on SWEPIC, Southwest Exotic Plant Information Clearinghouse.

Map of reported distribution (GIF) in the United States from the National Agricultural Pest Information System

Squarrose Knapweed Fact sheet. I.D, ecology, and control from Pacific Northwest Extension Publications. View as html or pdf

St. Johnswort (Hypericum perforatum)

Fact sheet (pdf) from San Francisco Peaks Weed Management Area, Coconino National Forest. Scroll down on SWEPIC, Southwest Exotic Plant Information Clearninghouse.

Identification and management (pdf) from Pacific Northwest Extension Publications (Oregon State University)

Identification, history, and biological control from the Weed Science Society of America

Map of reported distribution (GIF) in the United States from the National Agricultural Pest Information System

MontGuide fact sheet from Montana State University Extension. View as html or pdf

Toxicity in livestock from Purdue University’s School of Veterinary Medicine

Sulphur cinquefoil (Potentilla recta)

Analysis of Sulphur Cinquefoil in British Columbia (pdf), a comprehensive paper that describes ecology and management strategies. Working Paper 16 from BC Ministry of Forests, Forest Science Program

Comprehensive database including biogeographic associations, management, and fire ecology from the USDA Forest Service Fire Effects Information System

Fact sheet (pdf) from British Columbia Ministry of Agriculture and Food

A Guide to Weeds in British Columbia: Sulphur Cinquefoil (pdf), a profile from Weeds BC (British Columbia Ministry of Agriculture and Food)

Identification and management (pdf) from University of Nevada-Reno Cooperative Extension

TNC Species Management Summary on Potentilla recta

Syrian beancaper (Zygophyllum fabago)

Description and management practices from the WA Noxious Weed Control Board

Fact sheet from the California Department of Food and Agriculture’s EncycloWeedia website

Observations on Chemical Controls of African Rue and Syrian Beancaper in Western Nevada (pdf) from University of Nevada-Reno Cooperative Extension

Syrian Beancaper: Another New Noxious Weed Threatens Nevada (MS Word document) from University of Nevada-Reno Cooperative Extension. Scroll down to the “Natural Resources: Weeds” heading and click on the sixth title up from the bottom.

Tansy ragwort (Senecio jacobaea)

Fact sheet on identification and control and Pasture Management for Control of Tansy Ragwort from Pacific Northwest Extension Publications (Oregon State University)

Impacts on livestock (scroll down) from the USDA/ARS Poisonous Plant Research Laboratory

Map of reported distribution (GIF) in the United States from the National Agricultural Pest Information System

Tansy Ragwort description and control from WA Noxious Weed Control Board

Toothed spurge (Euphorbia dentata)

Brief description (on Idaho One Plan website) from Idaho's Noxious Weeds

Leafy, oblong, and toothed spurge from CA Encycloweedia. Complete info including managment and control

Water hyacinth (Eichhornia crassipes)

Comprehensive info from University of Florida Center for Aquatic and Invasive Plants

General and technical management information from the Washington Dept. of Ecology Non-Native Freshwater Plants program.

Management information and links from the Global Invasive Species Database

Many links to identification, control, and more information, from invasivespecies.gov

Species Management Summary from The Nature Conservancy

Yellow flag iris **(Iris pseudacorus)**

Description and ecology with alternative species to use in place of Yellow Flag Iris from the Washington Invasive Species Coalition

Fact sheet and control information from University of Florida Center for Aquatic and Invasive Plants

Links to fact sheet and treatment information on Yellow flag Iris as well as other invasive plants from Clark County, WA, Weed Management

Yellow (or meadow) hawkweed (Hieracium pretense)

Best Management Practices for the hawkweeds from King County (WA) Department of Natural Resources and Parks

Fact Sheet from Stevens County (WA) Noxious Weed Control Board

Montguide fact sheet from Montana State University Extension. View as html or pdf

Yellow starthistle (Centaurea solstitialis)

Yellow Starthistle Management Guide by DiTomaso, Kyser, and Pitcairn. Biology and ecology of yellow starthistle and its history in California; comprehensive overview of treatment methods. Full color, photos, 74 pp. $5 or free pdf download (8 MB).

Yellow starthistle information (and other weeds) from the Weed Research and Information Center, UC Davis. Introduction and spread, impacts, biology and ecology, management, and more.

A summary of control options from the above site.

Biology and biocontrol of yellow starthistle, from Invasive.org

Yellow starthistle Weed Watch from MSU Extension. Full-color pdf flyer with I.D., biology, and control info. Download or contact MSU Extension Publications for free copies.

Ten most wanted: crime fighting tactics to combat noxious weeds. University of Idaho pilot studies on the competitive and physiological limits on yellow starthistle's growth.

Yellow starthistle continues its spread in California 2006 article from "California Agriculture" summarizing rate of spread and current infestations.

Yellow toadflax (Linaria vulgaris)

Biology and Management of the Toadflaxes from Colorado State University Cooperative Extension. Compares and contrasts the biology, ecology, and management of yellow and Dalmatian toadflaxes. View as html or pdf

Fact sheet from Invasives on the Web (TNC invasive species website). Compares and contrasts the biology, ecology, and management of yellow and Dalmatian toadflaxes.

Identification and management from North Dakota State University Extension Service

Managing Yellow and Dalmatian Toadflax (pdf) from University of Nevada-Reno Cooperative Extension