Columbia University. Center for Environmental Research and Conservation.
University of Pennsylvania. The Pennsylvania Flora Project of Morris Arboretum.
See also: Invasive Plant Fact Sheets for additional invasive plants in Pennsylvania
North Carolina State University. Cooperative Extension. Going Native: Urban Landscaping for Wildlife with Native Plants.
University of Maine. Cooperative Extension.
See also: Maine Invasive Plants & Entire Series for entire series of 22 fact sheets and invasive plants brochure (available in HTML/PDF or for purchase)
University of California. Weed Research and Information Center.
See also: Weeds in Natural Areas for more information sheets
University of Nebraska - Lincoln. Cooperative Extension.
Google. YouTube; University of Wyoming Extension. Sustainable Management of Rangeland Resources Initiative Team.