When Identifying Mile-a-Minute Weed, Look for the Prickles and Ocrea

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Maine Natural Areas Program

For Immediate Release
August 24, 2023

When Identifying Mile-a-Minute Weed, Look for the Prickles and Ocrea 

Augusta, Maine — The Maine Department of Agriculture Conservation and Forestry (DACF) has confirmed the presence of mile-a-minute weed (Persicaria perfoliata) in the state. Following this discovery, the DACF received over 150 notifications from alert Mainers regarding mile-a-minute weed. All but two of the reports turned out to be other species. A handy photo identification document is available. This plant has strong and sharp prickles, which will cause painful scratches to an ungloved hand! 

Persicaria perfoliata

Other key features include the distinctly triangular leaves and peculiar circular leaf-like structures along the stem called the ocrea. 


Mile-a-minute weed is a fast-growing invasive vine native to India, Asia, and the Philippine Islands. Mile-a-minute weed derives its name from its astonishing growth rate of up to 6 inches per day or 25 feet in six to eight weeks. The vine poses a significant threat to yards, gardens, nurseries, natural areas, and agricultural lands, as it can smother young plants and trees under its dense growth.

The first confirmed occurrence of mile-a-minute weed in Maine was made at a private residence in Boothbay Harbor, where the alert landowner reported finding a mile-a-minute weed plant while cleaning up weeds that came with newly installed landscape plants. The subsequent finds have been reported from Winthrop and Islesboro. This invasive species is one of 33 plants listed on the DACF's do-not-sell list, notorious for hitchhiking on nursery stock and spreading rapidly.

Invasive species like mile-a-minute weed have the potential to cause severe harm to Maine's environment and economy. As part of our commitment to controlling and eradicating this invasive plant, the DACF urges the public to report any potential sightings promptly. If you encounter a vine resembling mile-a-minute weed, please visit the Maine Natural Areas webpage for identification information.

If the plant matches the description, we encourage you to take photos, note the location, and report the finding via email to Invasives.MNAP@maine.gov or call (207) 287-7545. 

For more information on mile-a-minute weed and other invasive species of concern in Maine, please visit https://www.maine.gov/dacf/mnap/features/invasive_plants/invasives.htm. Download the mile-a-minute weed identification resource at https://www.maine.gov/dacf/mnap/features/invasive_plants/mile-a-minute.pdf.


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Media Contact: Jim Britt