Identification and Reproduction

Identification: 

• Carpet burweed, is also known as lawn burrweed, it is a low-growing annual plant. 
• Forms a rosette with stems arranged in a sprawling pattern. Measures about 3-5 cm wide and 7 cm tall.  
• Individual plants have at most 10 hairy stems growing from the base. 
• Leaves are small, feathery and carrot or fern-like. 

• This plant is covered in flat seeds that have stiff hairs and are spined. 

Reproduction: 

• It reproduces by seed. 
• Up to 100 seeds per plant in a growing season. 
• Bur-like seeds easily attach to fur and clothing. 

Habitat & Ecology

• Carpet burweed is commonly invading exposed grasslands, pastures and recently disturbed sites. 
• It is also regarded as a common lawn weed, negatively impacting lawns, parks, playing fields and golf courses.

Impacts

Social: 

• Dead or alive, this plant poses a serious problem.
• If found on lawn will pose as a hazard for pets and humans because of its thorny nature. 

Ecological: 

• Once introduced, carpet burweed quickly spreads and forms a dense "carpet". 
• These dense mats prevent the growth of native species. 
• It has a competitive advantage over native vegetation as it flowers and seeds very early in the spring. 
• When it dies off in the summer it leaves patches of bare soil, allowing germination of its own seeds. 

Management

Prevention is a high priority for this species. 

• Early detection and eradication is the best control measures for this plant. 
• Learn to identify this plant and report sightings. 
• Identified infestations should be fenced off to limit accidental spread of seeds. 
• Clean and remove any seeds that may attach to clothing, shoes, equipment and pets when leaving an infested site. 
• Refrain from moving unknown soil and plant matter. 
• Maintain healthy and tall turf grass to prevent establishment of carpet burweed. 

Mechanical/Manual Control: 

• Small infestations can be hand pulled. Ensure removal is done before seed set to prevent further dispersal of seeds. 
• Plants should not be composted but bagged and thrown in the garbage. 

Resources

Download the factsheet from Garry Oak and Associated Ecosystems in British Columbia on Soliva sessilis: carpet burweed here. 

For more details check out the Invasive Species Compendium datasheet on Soliva sessilis. 

Header photo (Harry Rose).