Birdsfoot trefoil (Lotus corniculatus)

Yellow flowers of birdsfoot trefoil in a field.

 
 

Birdsfoot trefoil (Lotus corniculatus) was introduced to the United States for livestock forage and erosion control. It grows well in the Midwest and is most problematic in prairies and disturbed open areas, such as roadsides, where it forms dense mats that shade and chokes out native vegetation.

Description

Appearance

Birdsfoot trefoil is an herbaceous plant that grows 12-24 inches tall. It is a low-growing clover-like plant with a sprawling growth pattern.

Leaves and Stem

Three clover-like leaflets grow from short stems, with two additional leaflets at the base of each stem. The leaflets are up to ¾ inch long, and each grouping looks similar to a three-leaf clover. Stems of this plant can either be lying along the ground or partially upright.

Flowers

Yellow pea-like flowers are about ½ inch long and sometimes tinged with red. They occur in flat-topped clusters of 3-12 on a long stalk. Birdsfoot trefoil blooms through most of the summer, from May through August.

Seeds

One-inch long seedpods grow in clusters, resembling a bird's foot. Pods are brown to black, rounded, and about one inch long. Each pod contains up to 25 seeds.

Roots

Birdsfoot trefoil has a taproot.

Biology

This perennial herbaceous plant grows well in the Midwest and is most problematic in prairies and disturbed open areas, such as roadsides.

Origin and Spread

Birdsfoot trefoil is native to Europe and was introduced to the U.S. and Canada for livestock forage and erosion control along roadsides. It is still sold commercially. It spreads by seeds that are transported by animals, water, and machines (e.g., mowers). Prescribed fires can increase seed germination, making it troublesome in native prairies. Birdsfoot trefoil can be found in most counties in Minnesota. Refer to EDDMapS distribution maps for current distribution.

Don't be fooled by these look-alikes

  • Butter and eggs, Linaria vulgaris (invasive) - The leaves of butter and eggs are single, long, and narrow and are not in clusters of three as in birdsfoot trefoil.
  • Yellow sweetclover, Melilotus officinalis (invasive) - Yellow sweetclover has smaller flowers than birdsfoot trefoil and they grow along the stem, instead of in a flat-topped cluster like birdsfoot trefoil.
  • Other native and non-native legumes - There are many legume species present in Minnesota. Additional examples are non-native clovers (Trifolium species) and non-native medics (Medicago species) which have leaves with finely toothed edges as opposed to the smooth edges of birdsfoot trefoil.
 
Regulatory Classification

This species is not regulated. Birdsfoot trefoil has been assessed through the Minnesota Department of Agriculture's noxious weed regulation evaluation process. In the assessment document, it was recommended that birdsfoot trefoil should not be regulated to continue to allow its use in agronomic grazing systems. In terms of voluntary actions, it recommended that people do not intentionally seed birdsfoot trefoil in fields adjacent to native prairie management areas and do not include birdsfoot trefoil in wildlife or deer seed mixes. These voluntary actions will limit the chances of birdsfoot trefoil spreading into natural areas.

Threat to Minnesota

Birdsfoot trefoil forms dense mats that shade and chokes out native vegetation. It can degrade the prairie habitat.

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 mowing frequently at a height of less than 2 inches for several years. Unfortunately, this will be stressful to native plants as well as birdsfoot trefoil.

Herbicide control can be done by spot-spraying affected areas (after re-greening from a prescribed burn or mowing) with clopyralid (e.g., Transline). This selective herbicide also affects native plants of the sunflower and pea families. It is a systemic herbicide that is taken up by plants and moves within the plant, which can kill leaves, stems, and roots.

Reporting

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

Resources