Yellow Toadflax
Yellow Toadflax
Linaria vulgaris
Colorado List B - Control required in Jefferson County
General
- Family: Plantaginaceae (Plantain)
- Has been used as an ornamental but no longer available in Colorado
- Herbaceous perennial
- Introduced from Eurasia
Common names
- Wild snapdragon, butter and eggs
Habitat
- Found in pastures, rangelands, roadsides, gravel pits and grasslands
Plant
Vegetation
- Leaves are pale green, lance shaped; 1 to 2 inches long, one eighth to one quarter inch wide, waxy
- Mature plants grow up to 3 feet tall
- Produces 1 to 25 floral stems
Roots
- Lateral roots; new plants can develop from root buds 2 to 3 weeks after germination and from root fragments as small as one quarter inch long
Flower
- Color: yellow with orange throat; dense cluster of 15 to 20 flowers at the end of stems
- Season: May to August
- Size: three quarters to 1 inch long; includes a spur typically the same length as the flower
Seed
- Each plant can produce up to 30,000 seeds
- Seed matures from July through September
- Viability and germination are low
Seedling
- Early May, some fall germination possible
Reproduction
- Mainly vegetative; also by seed
Control
Biological
- Calophasia lunula, a defoliating moth
- Eteobalea intermediella, a root-boring moth
- Mecinus janthinus, a stem-boring weevil
Chemical
Cultural
- Fertilization to promote grass cover
- Prevention - maintain health of site
- Removal - not effective unless done the first year plants germinate; otherwise this will fragment the roots and give rise to many more plants
- Re-vegetation of highly disturbed sites
Mechanical
- 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. No specific recommendation or endorsement is made or implied by listing methods or products.
Treatment Timeline
Jan | Feb | Mar | Apr | May | June | July | Aug | Sept | Oct | Nov | Dec | |
Control | ||||||||||||
Removal | Not recommended - root fragments will regrow | |||||||||||
Herbicide | ||||||||||||
Growth | ||||||||||||
Vegetative | ||||||||||||
Flowering | ||||||||||||
Seed |
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Invasive Species Management
Physical Address
700 Jefferson County Parkway, Suite 100
Golden, CO 80401
Phone 303-271-5989
Hours
Monday - Thursday
6:30 a.m. - 5:00 p.m.