Butter and eggs or common toadflax (Linaria vulgaris)

Yellow flowers of butter and eggs plants.

 
 

Butter and eggs is a 1-3 feet tall plant that has yellow flowers with a long spur. It is commonly found along roadsides and other disturbed areas.

Description

Appearance

Butter and eggs is a perennial herbaceous plant that grows 1-3 feet tall. It has multiple erect stems growing from rootstalks.

Leaves and Stem

Leaves are narrow with smooth edges and are 0.5-1.5 inches long. They are arranged alternately along the stem.

Flowers

This plant has bright yellow flowers with a long spur that are arranged in an elongated cluster of 15-20 flowers along each stem. The center of the flower is a darker yellow than the rest of the flower giving the plant its common name "butter and eggs." Plants bloom from mid-July until late September. Butter and eggs is in the snapdragon family so the flowers look similar to snapdragons.

Seeds

Small seeds are easily dispersed by wind and water, and stay viable in the soil for up to 8 years.

Roots

The roots of the plants can grow to the side and send up new plant stems. Butter and eggs can also spread vegetatively as root fragments can produce new plants.

Biology

Butter and eggs is a perennial plant. It produces flowers and seeds and can also spread by sending up new shoots from spreading roots. Root fragments can also produce new plants. This plant has the ability to adapt to various site conditions.

Origin and Spread

Butter and eggs is native to the steppes of Europe and Asia. In the 1700s this plant was introduced into North America as an ornamental plant, and is sometimes still sold commercially. In Minnesota, it grows on gravelly to sandy soil along roadsides, railroad yards, waste places, dry fields, pastures, and croplands.

Refer to EDDMapS Distribution Maps for current distribution.

Don't be fooled by these look-alikes

  • Dalmatian toadflax, Linaria dalmatica (invasive) – Dalmatian toadflax leaves are wide and heart shaped while the leaves of butter and eggs are linear and narrow.
  • Snapdragon, Antirhhinum majus (non-native) – Snapdragons are commonly sold as annuals for gardens. They can come in many colors. Snapdragon flowers do not have the long spur at the base of the flower that butter and eggs and Dalmatian toadflax have.
 
Regulatory Classification

Butter and eggs is not regulated.

Threat to Minnesota
  • By spreading vegetatively through horizontal lower branches that root freely when they contact the soil, butter and eggs can form dense patches. It competes well against less aggressive native plants in gravelly and sandy soils.
  • It presents a problem in prairie reconstruction projects once it has established itself.
  • It can be mildly toxic to cattle and degrade pastures.
What you should do

One way that invasive plant seeds and fragments can spread is in soil. Sometimes plants are planted purposefully. You can prevent the spread of invasive plants.

PlayCleanGo: Stop Invasive Species in Your Tracks

  • REMOVE plants, animals & mud from boots, gear, pets & vehicle.
  • CLEAN your gear before entering & leaving the recreation site.
  • STAY on designated roads & trails.
  • PLANT non-invasive species.
Native Substitutes
 
Control Methods

Mechanical control can be done by hand pulling or digging the plant up by hand. Frequent mowing can weaken the plant.

Herbicide control can be done using systemic herbicides, which are taken up by plants and move within the plant, killing leaves, stems, and roots. Always follow herbicide label instructions. 2,4-D is an herbicide that is generally easy to find, but it may require multiple years of application. Additional herbicides reported to be effective for butter and eggs are metsulfuron, chlorsulfuron, imazapic, and picloram.

Several insects were unintentionally introduced to the United States that appear to provide some biocontrol of butter and eggs. The Biological Control section on page six of the USDA document on butter and eggs (yellow toadflax) provides more details.

See Minnesota Department of Agriculture disposal information if needed.

Reporting

This species is unregulated, but if you'd like to add to the public information about this species you can report new occurrences by submitting a report through EDDMapS Midwest.

Resources