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  • Noxious Weed Identification List

    Yellow Toadflax

    Linaria vulgaris

    Info Sheet Adobe PDF Icon


    Colorado List B - Control required in Jefferson County



    • Family: Scrophulariaceae (Figwort)
    • Herbaceous perennial
    • Introduced from Eurasia
    • Has been used as an ornamental but no longer available in Colorado


    Common names

    • Wild snapdragon, butter and eggs



    • Found in pastures, rangelands, roadsides, gravel pits and grasslands




    • Mature plants grow up to 3 feet tall
    • Produces 1 to 25 floral stems
    • Leaves are pale green, lance shaped; 1 to 2 inches long, 1/8 to 1/4 inch wide, waxy



    • Lateral roots; new plants can develop from root buds 2 to 3 weeks after germination and from root fragments as small as 1/4 inch long



    • Color: yellow with orange throat; dense cluster of 15 to 20 flowers at the end of stems
    • Season: May to August
    • Size: 3/4 to 1 inch long; includes a spur typically the same length as the flower



    • Each plant can produce up to 30,000 seeds
    • Seed matures from July through September
    • Viability and germination are low



    • Early May, some fall germination possible



    • Mainly vegetative; also by seed




    • Calophasia lunula, a defoliating moth
    • Eteobalea intermediella, a root-boring moth
    • Mecinus janthinus, a stem-boring weevil


    Chemical (retreatment required for several years)

    Please refer to our Info Sheet Adobe PDF Icon



    • Prevention – maintain health of site
    • Fertilization to promote grass cover
    • Revegetation of highly disturbed sites
    • Removal - not effective unless done the first year plants germinate; otherwise this will fragment the roots and give rise to many more plants



    • Burning - Not recommended; areas disturbed by fire are susceptible to invasion due to lack of competition from desirable plants 
    • Grazing - Not effective; intensive grazing contributes to conditions that help spread plants; may be toxic to livestock 
    • Mowing - Not recommended 

    More Information


    Use all chemicals according to the manufacturer's label. Listing the above methods or products does not imply a specific recommendation or endorsement.

    Alicia Doran
    Weed & Pest Management Specialist


    Last Updated: 8-5-2013