Linaria vulgaris - P. Mill.
Other English Common Names: Yellow Toadflax
Other Common Names: butter and eggs
Taxonomic Status: Accepted
Related ITIS Name(s): Linaria vulgaris P. Mill. (TSN 33216)
Unique Identifier: ELEMENT_GLOBAL.2.143356
Element Code: PDSCR110E0
Informal Taxonomy: Plants, Vascular - Flowering Plants - Figwort Family
Kingdom Phylum Class Order Family Genus
Plantae Anthophyta Dicotyledoneae Scrophulariales Scrophulariaceae Linaria
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Concept Reference
Concept Reference: Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Concept Reference Code: B94KAR01HQUS
Name Used in Concept Reference: Linaria vulgaris
Conservation Status

NatureServe Status

Global Status: GNR
Global Status Last Changed: 22Mar1994
Rounded Global Status: GNR - Not Yet Ranked
Nation: United States
National Status: NNA
Nation: Canada
National Status: NNA (13Oct2016)

U.S. & Canada State/Province Status
Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
United States Alabama (SNA), Alaska (SNA), Arizona (SNA), Arkansas (SNA), California (SNA), Colorado (SNA), Connecticut (SNA), Delaware (SNA), District of Columbia (SNA), Florida (SU), Georgia (SNR), Idaho (SNA), Illinois (SNA), Indiana (SNA), Iowa (SNA), Kansas (SNA), Kentucky (SNA), Louisiana (SNA), Maine (SNA), Maryland (SNA), Massachusetts (SNR), Michigan (SNA), Minnesota (SNA), Mississippi (SNA), Missouri (SNA), Montana (SNA), Nebraska (SNA), Nevada (SNA), New Hampshire (SNA), New Jersey (SNA), New Mexico (SNA), New York (SNA), North Carolina (SNA), North Dakota (SNA), Ohio (SNA), Oklahoma (SNA), Oregon (SNA), Pennsylvania (SNA), Rhode Island (SNA), South Carolina (SNA), South Dakota (SNA), Tennessee (SNA), Texas (SNA), Utah (SNA), Vermont (SNA), Virginia (SNA), Washington (SNA), West Virginia (SNA), Wisconsin (SNA), Wyoming (SNA)
Canada Alberta (SNA), British Columbia (SNA), Labrador (SNA), Manitoba (SNA), New Brunswick (SNA), Newfoundland Island (SNA), Northwest Territories (SNA), Nova Scotia (SNA), Ontario (SNA), Prince Edward Island (SNA), Quebec (SNA), Saskatchewan (SNA), Yukon Territory (SNA)

Other Statuses

NatureServe Global Conservation Status Factors

Other NatureServe Conservation Status Information

U.S. States and Canadian Provinces

Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
Color legend for Distribution Map
NOTE: The distribution shown may be incomplete, particularly for some rapidly spreading exotic species.

U.S. & Canada State/Province Distribution
United States AKexotic, ALexotic, ARexotic, AZexotic, CAexotic, COexotic, CTexotic, DCexotic, DEexotic, FL, GA, IAexotic, IDexotic, ILexotic, INexotic, KSexotic, KYexotic, LAexotic, MA, MDexotic, MEexotic, MIexotic, MNexotic, MOexotic, MSexotic, MTexotic, NCexotic, NDexotic, NEexotic, NHexotic, NJexotic, NMexotic, NVexotic, NYexotic, OHexotic, OKexotic, ORexotic, PAexotic, RIexotic, SCexotic, SDexotic, TNexotic, TXexotic, UTexotic, VAexotic, VTexotic, WAexotic, WIexotic, WVexotic, WYexotic
Canada ABexotic, BCexotic, LBexotic, MBexotic, NBexotic, NFexotic, NSexotic, NTexotic, ONexotic, PEexotic, QCexotic, SKexotic, YTexotic

Range Map
No map available.

U.S. Distribution by County Help
State County Name (FIPS Code)
NM Lincoln (35027)
* Extirpated/possibly extirpated
U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
13 Rio Hondo (13060008)+
+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated
Ecology & Life History Not yet assessed
Economic Attributes Not yet assessed
Management Summary Not yet assessed
Population/Occurrence Delineation Not yet assessed
Population/Occurrence Viability
U.S. Invasive Species Impact Rank (I-Rank)
Disclaimer: While I-Rank information is available over NatureServe Explorer, NatureServe is not actively developing or maintaining these data. Species with I-RANKs do not represent a random sample of species exotic in the United States; available assessments may be biased toward those species with higher-than-average impact.

I-Rank: High/Low
Rounded I-Rank: Unknown
I-Rank Reasons Summary: Linaria vulgaris, also called Yellow Toadflax or Butter-and-Eggs, is a species once planted as an ornamental. This species produces attractive yellow and orange flowers, but is an aggressive invader in many parts of the United States. It is common throughout the eastern U.S. and has been increasingly problematic in the West and particularly in Colorado, where it has infested more than 40,000 acres. This species impacts the ecosystems it invades by increasing erosion, and displacing native vegetation. Once established in a disturbed area is it capable of invading nearby undisturbed areas because its root system is extensive and produces secondary shoots from the roots. It also produces large numbers of seeds yearly.
Subrank I - Ecological Impact: Medium/Low
Subrank II - Current Distribution/Abundance: High/Medium
Subrank III - Trend in Distribution/Abundance: Medium/Low
Subrank IV - Management Difficulty: High/Medium
I-Rank Review Date: 05Oct2004
Evaluator: Fellows, M., rev. L. Oliver (10/2004)
Native anywhere in the U.S?

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Screening Questions

S-1. Established outside cultivation as a non-native? YES
Comments: Yellow Toadflax is a non-native species present throughout the United States (Kartesz 1999).

S-2. Present in conservation areas or other native species habitat? Yes
Comments: Found in natural areas in Colorado (Beck 2001).

Subrank I - Ecological Impact: Medium/Low

1. Impact on Ecosystem Processes and System-wide Parameters:Moderate significance
Comments: This toadflax species and others do affect the abiotic processes in the ecosystems where they are found. Specifically, the Yellow Toadflax increases erosion where it invades (Kadrmas and Johnson) and probably changes the soil characteristics in other ways too.

2. Impact on Ecological Community Structure:Low significance
Comments: Linaria vulgaris affects at least one vegetative layer since it is a herbaceous perennial (Kadrmas and Johnson).

3. Impact on Ecological Community Composition:High/Moderate significance
Comments: This species is an excellent invader of disturbed habitat and once established it can invade undisturbed natural areas and drastically alter the community composition wher it invades (Beck 2001). The Yellow Toadflax, or Butter-and-Eggs spreads via a well developed and quickly growing root system. The roots can produce vegetative shoots two to three weeks after germination and established plants have well developed root systems (Beck 2001). Further, plants in their first year can produce 90 to 100 secondary shoots from their roots and it is reported that this species ultimately displaced native vegetation (Kadrmas and Johnson).

4. Impact on Individual Native Plant or Animal Species:Insignificant
Comments: No information was found that suggests this species disproportionately affects certain native species.

5. Conservation Significance of the Communities and Native Species Threatened:Low significance
Comments: It is reported that this species is capable and does invade intact natural areas adjacent to disturbed areas where it is established (Beck 2001). Further, this species has spread into high mountain valleys and parks in Colorado (Beck 2001) so it is possible it has invaded vulnerable native species habitat or ecological communities and that these invasions are undocumented.

Subrank II. Current Distribution and Abundance: High/Medium

6. Current Range Size in Nation:High significance
Comments: Found throughout the US, including Alaska (Kartesz 1999).

7. Proportion of Current Range Where the Species is Negatively Impacting Biodiversity:Medium/Low significance
Comments: This species is reported as noxious in 7 states (Kartesz 1999) but is also known to be present in all states in the United States and may be negatively impacting biodiversity in more than 7 states.

8. Proportion of Nation's Biogeographic Units Invaded:High significance
Comments: Inferred from current distribution (Kartesz 1999; NRCS 2004) and ecoregion boundaries (TNC 2001).

9. Diversity of Habitats or Ecological Systems Invaded in Nation:Medium/Low significance
Comments: Disturbed habitats invaded include roadsides, waste gounds and overgrazed rangelands and natural areas invaded include high mountain valleys and parks (Beck 2001). Another sources says that this species invades and displaces native vegetation in many habitats (Kadrmas and Johnson).

Subrank III. Trend in Distribution and Abundance: Medium/Low

10. Current Trend in Total Range within Nation:High/Moderate significance
Comments: In the 1970s Linaria vulgais was reported common in the eastern United States and local on the Pacific Coast (USDA 1970). More recent reports in the west suggest that this species is aggressive and spreading (Beck 2001, (Kadrmas and Johnson) in the west. Beck 2001 reports that the Yellow Toadflax infests 40,800 acres of land in Colorado alone.

11. Proportion of Potential Range Currently Occupied:Insignificant
Comments: The Yellow Toadflax has already invaded every state in the United States, except Hawaii, is reported to be common in the eastern United States (USDA 1970) and spreading in the west (Beck 2001, Kadrmas and Johnson).

12. Long-distance Dispersal Potential within Nation:Insignificant
Comments: No information was found about this species dispersing long distances. The Yellow Toadflax was originally introduced into the United States as an ornamental and for medicinal purposes (Beck 2001) and most usually spreads by shoots that bud from its well developed root system (Beck 2001, Kadrmas and Johnson).

13. Local Range Expansion or Change in Abundance:Moderate significance
Comments: This species is locally expanding at a rapid rate in at least Colorado (Beck 2001).

14. Inherent Ability to Invade Conservation Areas and Other Native Species Habitats:Moderate significance
Comments: Linaria vulgaris usually invades disturbed areas including roadsides, abandoned lots, clearings, gravel pits and other disturbed places. Once it is established in a disturbed area, it is capable of spreading into nearby undisturbed habitats (Beck 2001).

15. Similar Habitats Invaded Elsewhere:Unknown
Comments: Information on habitats invaded elsewhere was not found.

16. Reproductive Characteristics:Moderate significance
Comments: Yellow Toadflax has several characteristics which allow it easily invade areas, including an extensive root system that produces secondary shoots. It is reported that in the first year a plant can produce up to 100 secondary shoots from its roots (Kadrmas and Johnson). Further, this species produces copious seeds; large plants can produce 500,000 seeds which can remain viable in the soil for up to ten years (Kadrmas and Johnson).

Subrank IV. General Management Difficulty: High/Medium

17. General Management Difficulty:High significance
Comments: One report states "All toadflax species are very difficult to control and management plans should integrate as many strategies as possible to increase potential for success" (Beck 2001).

18. Minimum Time Commitment:Medium/Low significance
Comments: Control of toadflaxes requires several years at the least depending on the method (Beck 2001).

19. Impacts of Management on Native Species:High/Low significance
Comments: Since this species has to be actively managed for, there is certainly some negative impact on the native species in the area.

20. Accessibility of Invaded Areas:High/Low significance
Comments: Ornamental (Beck 2001).

Botanical data developed by NatureServe and its network of natural heritage programs (see Local Programs), The North Carolina Botanical Garden, and other contributors and cooperators (see Sources).

  • Agricultural Research Service. 1970. Common weeds of the United States. Agricultural Research Service, U.S. Department of Agriculture. Washington, D.C. 463 pp.

  • Beck, K.G. 2001. Biology and Management of the Toadflaxes. Natural Resources Seris Range No. 3.114. Colorado State University Cooperative Extension. Available ONLINE: Accessed 2004.

  • Cody, W.J. 1994. The flora of the Yukon Territory: Additions, range extensions, and comments. The Canadian Field-Naturalist 108:428-467.

  • Cody, W.J., C.E. Kennedy, B.Bennett, and J. Staniforth. 2003. New records of vascular plants in the Yukon Territory V. Canadian Field-Naturalist 117(2):278-301

  • Davidson, S. 2016. Invasive species in Kluane Natinal Park and Reserve. Unpublished report for Parks Canada. 5 pp.

  • Deam, C. C. 1940. Flora of Indiana. Division of Forestry, Dept. of Conservation, Indianapolis, Indiana. 1236 pp.

  • Douglas, G.W., D. Meidinger, and J. Pojar, eds. 2000. Illustrated Flora of British Columbia, Vol. 5, Dicotyledons (Salicaceae through Zygophyllaceae) and Pteridophytes. B.C. Minist. Environ., Lands and Parks, and B.C. Minist. For., Victoria. 389pp.

  • Herbarium, Department of Botany, University of Manitoba, Winnipeg, Manitoba, Canada.

  • Herbarium, Museum of Man and Nature, 190 Rupert Avenue, Winnipeg, Manitoba.

  • Kadrmas, T. and W. S. Johnson. Managing Yellow and Dalmatian Toadflax. Factsheet FS-02-96. University of Nevada Cooperative Extension. Online at: Accessed on: Oct. 5, 2004.

  • Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.

  • Kartesz, J.T. 1996. Species distribution data at state and province level for vascular plant taxa of the United States, Canada, and Greenland (accepted records), from unpublished data files at the North Carolina Botanical Garden, December, 1996.

  • Kartesz, J.T. 1999. A synonymized checklist and atlas with biological attributes for the vascular flora of the United States, Canada, and Greenland. First edition. In: Kartesz, J.T., and C.A. Meacham. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden, Chapel Hill, N.C.

  • Saner, M.A., D.A. Clements, M.R. Hall, D.J. Dohan, and C.W. Crompton. 1995. The biologr of Canadian weeds. 105. Linada vulgans Mill. Canadian Journal of Plant Science 75: 525-537.

  • Scoggan, H.J. 1978. The Flora of Canada. National Museum of Natural Sciences, National Museum of Canada, Publ. in Botany 7(4).

  • Swink, F., and G. Wilhelm. 1994. Plants of the Chicago Region. Morton Arboretum. Lisle, Illinois.

  • The Nature Conservancy. 2001. Map: TNC Ecoregions of the United States. Modification of Bailey Ecoregions. Online . Accessed May 2003.

  • USDA, ARS, National Genetic Resources Program. 2001. Germplasm Resources Information Network - (GRIN). [Online Database]. National Germplasm Resources Laboratory, Beltsville, Maryland.URL: (Accessed 2004)

  • USDA, NRCS. 2004. The PLANTS Database, Version 3.5 ( . National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

  • Weber, W. A. and R. C. Wittmann. 1992. Catalog of The Colorado Flora: A Biodiversity Baseline. University Press of Colorado, Niwot, CO.

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