Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): Kevin R. McCartney; Sunil Kumar; Sharlene E. Sing; Sarah M. Ward
    Date: 2019
    Source: Invasive Plant Science and Management. 12: 97-111.
    Publication Series: Scientific Journal (JRNL)
    Station: Rocky Mountain Research Station
    PDF: Download Publication  (1.0 MB)


    Invasive populations of Dalmation toadflax [Linaria dalmatica (L.) Mill.] and yellow toadflax (Linaria vulgaris Mill.) are widespread throughout the Intermountain West, where gene flow between these nonnative species is producing vigorous and fertile hybrids. These hybrid toadflax populations are less responsive to herbicides than either parent species, and biocontrol agents routinely released on L. dalmatica and L. vulgaris often fail to establish on hybrid hosts. Early detection of hybrid Linaria populations is therefore essential for effective management, but resources are limited for scouting large expanses of range and wildland. We used species distribution modeling to identify environmentally suitable areas for these invasive Linaria taxa in Montana, Wyoming, and Colorado. Areas suitable for hybrid Linaria establishment were estimated using two different modeling approaches: first, based on known hybrid occurrence and associated environmental conditions, and second, based on zones environmentally suitable for co-occurrence of the parent species. This also allowed comparison of different model outputs, especially relevant when modeling emerging invasives, such as novel hybrids, with minimal occurrence data. Combining the two model outputs identified areas at greatest risk of hybrid Linaria invasion, including parts of north-central Montana, where model estimates indicate the hybrid may spread without prior co-invasion of the parents. Potential hybrid hot spots were also identified in western Montana; northwestern, northeastern, and southeastern Wyoming; and the Western Slope and Front Range of Colorado. Despite relatively few confirmed occurrences of hybrid populations to date, our results indicate that extensive spread of hybrid populations is possible within the studied area. Model-based maps of potential Linaria distributions will allow area weed managers to direct limited resources more effectively for locating and controlling these invaders.

    Publication Notes

    • You may send email to to request a hard copy of this publication.
    • (Please specify exactly which publication you are requesting and your mailing address.)
    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.


    McCartney, Kevin R.; Kumar, Sunil; Sing, Sharlene E.; Ward, Sarah M. 2019. Using invaded-range species distribution modeling to estimate the potential distribution of Linaria species and their hybrids in the U.S. northern Rockies. Invasive Plant Science and Management. 12: 97-111.


    Google Scholar


    dalmatian toadflax, hybridization, Linaria dalmatica, Linaria vulgaris, MaxEnt, species distribution modeling, yellow toadflax

    Related Search

    XML: View XML
Show More
Show Fewer
Jump to Top of Page