Diffuse Knapweed

Scientific name: Centaurea diffusa Lam.

Synonym: Acosta diffusa (Lam.)

Common names: Diffuse knapweed, white knapweed, spreading knapweed, tumble knapweed

Native To: Eurasia

Date of U.S. Introduction: 1800s

Images: Invasive.org and Google

Means of Introduction: Introduced accidentally through contaminated seed

Impact: Crowds out native species

Current U.S. Distribution: PLANTS Database map (see complete PLANTS Profile for county distribution and native status)

Management Plans: Plants / Knapweeds

Selected Internet Resources:

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

Centaurea diffusa Lam.
Integrated Taxonomic Information System.
Taxonomy

Centaurea diffusa Lam. (Diffuse Knapweed) - Noxious and Nuisance Plant Management Information System (PMIS)
United States Army Corps of Engineers. Engineer Research and Development Center. Environmental Laboratory.
Identification/Description; Photographs; Impacts; Habitat; Distribution

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

Centaurea diffusa Lam. - Germplasm Resources Information Network (GRIN)
USDA. ARS. National Genetic Resources Program.
Taxonomy; Distribution; Legal Aspects

Biology and Biological Control of Knapweed, FHTET-2001-07, 2nd Edition
USDA. Forest Service.
Taxonomy; Identification/Description; Photographs; Distribution; Introduction History; Impacts; Life Cycle; Habitat; Controls

Diffuse Knapweed - Weed of the Week (Dec 18, 2006; PDF | 76 KB)
USDA. FS. Northeastern Area. Forest Health Protection.
Identification/Description; Photographs; Introduction History; Impacts; Habitat; Distribution; Controls

Centaurea diffusa - Fire Effects Information System (FEIS)
USDA. Forest Service. Rocky Mountain Research Station. Fire Sciences Laboratory.
Taxonomy; Identification/Description; Introduction History; Impacts; Life Cycle; Habitat; Distribution; Controls; Special Note: References

Noxious Weed: Diffuse Knapweed
USDA. Sawtooth National Forest.
Identification/Description; Photographs; Controls

Plant profile for Centaurea diffusa - PLANTS Database
USDA. NRCS. National Plant Data Center.
Taxonomy; Distribution; Legal Aspects

Diffuse Knapweed, Tumble Knapweed (PDF | 560 KB)
DOI. FWS. Hanford Reach National Monument.
Identification/Description; Photographs; Impacts; Controls

An Assessment of Exotic Plant Species of Rocky Mountain National Park: Centaurea diffusa Lam.
DOI. Northern Prairie Wildlife Research Center.
Impacts; Habitat; Distribution; Controls; Special Note: References

Diffuse Knapweed
Arizona Department of Transportation. Intermodal Transportation Division.
Identification/Description; Life Cycle; Habitat; Controls; Legal Aspects

Centaurea genus - EncycloWeedia
California Department of Food and Agriculture.
Identification/Description; Introduction History; Impacts; Life Cycle; Habitat; Distribution; Dispersion; Controls

Diffuse Knapweed - Best Management Practices Weed Profile (PDF | 213 KB)
Colorado State Parks.
Identification/Description; Illustrations; Introduction History; Impacts; Habitat; Distribution; Controls; Special Note: References

Diffuse Knapweed - Noxious Weed Information Series (PDF | 152 KB)
State of Colorado. Jefferson County. Weed and Pest Management Program.
Identification/Description; Photographs; Habitat; Controls

Diffuse Knapweed (Centaurea diffusa)
State of Colorado. Larimer County. Weed Control District.
Identification/Description; Photographs; Impacts; Dispersion; Controls

Diffuse Knapweed - Idaho's Noxious Weeds
Idaho Association of Soil Conservation Districts. Idaho OnePlan.
Identification/Description; Photographs; Introduction History; Distribution; Controls

Diffuse Knapweed
Washington State Noxious Weed Control Board.
Identification/Description; Photographs; Introduction History; Impacts; Habitat; Distribution; Controls; Special Note: References

Diffuse Knapweed
State of Washington. King County Department of Natural Resources. Water and Land Resources Division.
Identification/Description; Photographs; Impacts; Legal Aspects

Diffuse knapweed (PDF | 149 KB)
Colorado State University. Colorado Environmental Pesticide Education Program.
Identification/Description; Introduction History; Impacts; Life Cycle; Distribution; Controls; Legal Aspects; Special Note: Resources

Diffuse and Spotted Knapweed
Colorado State University. Cooperative Extension.
Identification/Description; Illustrations; Impacts; Life Cycle; Habitat; Distribution; Dispersion; Controls

Montana Knapweeds: Identification, Biology, and Management
Montana State University. Extension Service.
Identification/Description; Photographs; Introduction History; Distribution; Controls

Spotted and Diffuse Knapweed - Noxious Weeds of Nebraska (PDF | 387 KB)
University of Nebraska - Lincoln. Cooperative Extension.
Identification/Description; Photographs; Introduction History; Life Cycle; Distribution; Dispersion; Controls

Managing Diffuse Knapweed (PDF | 285 KB)
University of Nevada - Reno. Cooperative Extension.
Identification/Description; Photographs; Impacts; Controls

Diffuse Knapweed Wanted Poster--Dead, Not Alive! (PDF | 185 KB)
University of Nevada - Reno. Cooperative Extension.
Identification/Description; Photographs

Know Your Knapweeds
North Dakota State University. Extension Service.
Identification/Description; Distribution; Controls

Identification and Control of Knapweed Species in Central and Eastern Oregon
Oregon State University Extension and Experiment Station.
Identification/Description; Photographs; Impacts; Controls

Diffuse Knapweed - Guide to Weeds in British Columbia
British Columbia Ministry of Agriculture Food and Fisheries (Canada).
Identification/Description; Photographs; Impacts; Habitat; Distribution; Dispersion

Centaurea diffusa (herb) - ISSG Global Invasive Species Database
World Conservation Union. Invasive Species Specialist Group.
Taxonomy; Identification/Description; Photographs; Impacts; Life Cycle; Habitat; Distribution; Controls

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

Centaurea diffusa
Discover Life.
Identification/Description; Photographs; Introduction History; Impacts; Life Cycle; Habitat; Distribution; Dispersion; Controls

Spotted, Diffuse and Russian Knapweed - IVM Technical Bulletin
Integrated Pest Management Information Service.
Identification/Description; Impacts; Life Cycle; Distribution; Controls

White Knapweed
Invasive.org.
Photographs

Diffuse Knapweed
Montana Weed Control Association.
Identification/Description; Photographs; Impacts; Habitat

Centaurea diffusa (Diffuse Knapweed)
Nature Conservancy. Global Invasive Species Initiative.
Identification/Description; Introduction History; Impacts; Life Cycle; Habitat; Distribution; Dispersion; Controls; Special Note: Weed Notes and Element Stewardship Abstract with excellent set of references