- Auburn University – Weed ID Database
- Colorado State University – Common Weeds Identification Page
- Iowa State University – Weed Identification Resources
- Kansas Department of Agriculture – Weed Photo Gallery
- Kansas State University – Weed Identification
- Michigan State University – Identifying Weeds in Field Crops
- New Mexico State University – Weed Information
- Noble Foundation – Plant Image Gallery
- Northeastern Weed Science Society – Weed Identification Pages
- Oregon State University – PNW Weed Identification Module
- Ohio State University – Weed Identification
- Oregon State University – Weed Identification
- Penn State University – Weed Identification
- Purdue University – NRCA – Weed Identification
- Rutgers University – New Jersey Weed Gallery
- Southeastern Flora – A Southeastern US Plant Identification Resource
- University of Arizona – Weed Photo Gallery
- University of California- Agriculture and Natural Resources – Weed Identification
- University of California – Agriculture and Natural Resources – Weed Photo Gallery
- University of Florida – Weed Identification
- University of Illinois
- University of Illinois – Weeds of the North Central States
- University of Massachusetts – Weed Herbarium
- University of Minnesota – Annual Grass and Perennial Weed Identification
- University of Missouri – Weed ID Guide
- University of Nevada – Weed Identification Guide
- University of Wisconsin – Weed ID Tool
- University of Wyoming – Weed Identification Guide
- USDA Plants Database
- Virginia Tech – Weed Identification Guide
- Auburn University – Turfgrass Weed Identification
- Cornell University – Turfgrass and Landscape Weed ID page
- Michigan State University – Turf Weeds Program
- North Carolina State University – Turf Weed ID
- Penn State University – Center for Turfgrass Science – Plant ID page
- Purdue University – Turf Weed Identification
- Texas A&M University – Turfgrass Weed Identification
- University of Georgia – Turfgrass Weeds
- University of Illinois Turfgrass Program – Midwestern Turfgrass Weed Identification
- University of Kentucky – Turfgrass Weed Identification
- University of Maryland- Weed Identification Photos
- University of Tennessee – Turfgrass Weed Identification