BUCKLAND — Peggy Warwick was on a walk one day in her neighboring town when she came across a peculiar looking plant featuring triangular leaves, curved thorns and saucer-shaped leaves on the stem.

Soon enough, Warwick, a member of Shelburne’s Open Space Committee, was alerting the Massachusetts Department of Agricultural Resources (MDAR) about a new invader in town. The plant she found near the Buckland Post Office on Upper Road was mile-a-minute vine, a fast-growing invasive species she had learned about by working with a state biologist trying to eradicate the plant.

“I ripped it out, it was the only plant, which was amazing,” Warwick said.

Mile-a-minute vine, also known as asiatic tearthumb, is an invasive species native to eastern Asia — from Japan west and south to the Philippines — that was introduced to a Pennsylvania nursery in the 1930s through contaminated seeds, according to the U.S. Department of Agriculture.

Alongside its metallic blue fruit, the invader’s defining trait is its ability to grow up to 6 inches in one day. Left unchecked, the plant climbs over trees and posts and creates what MDAR environmental biologist Jennifer Forman Orth described as a “carpet” of vines, which crowds out other species native to Massachusetts.

“The interesting thing about mile-a-minute vine is it’s an annual plant. If you pull it out, it’s not going to grow back,” Forman Orth said. “The way it’s spreading is through seeds. … The seed can get caught up in soil that is being transported around or in construction or farming equipment.”

Forman Orth and Karro Frost, a conservation planning botanist with MassWildlife’s Natural Heritage and Endangered Species Program, said the seeds are extremely hardy and need to be destroyed to ensure they don’t sprout again. Forman Orth said the seeds can last up to six years in soil.

Buckland is the farthest west the plant has been discovered in Massachusetts, although previous infestations have been found in Deerfield and Montague. There was a previous infestation in Greenfield, but it was eradicated by 2020, according to Frost. Another infestation of the plant was removed in Buckland last year.

In Deerfield, Frost said much of the infestation lies along River and McClelland Farm roads, and some mile-a-minute vine remains in the Montague Plains.

“It’s not spreading as fast as it has in other places in eastern Mass. and we have eradicated it in one location [here], but it’s proving pretty stubborn in other places,” Frost said.

The plant does best in “edge habitats,” which Forman Orth said are places where forests meet open fields, roadsides or in power line right of ways. Experts, she said, are unsure as to why the plant has yet to take a deeper hold on western Massachusetts, especially compared to the southeastern area of the state.

Removing mile-a-minute vine

If one comes across mile-a-minute vine, MDAR and MassWildlife encourage reporting the sighting, so experts can confirm its identity.

There are several other plants that look similar to mile-a-minute vine and MDAR has laid out three identifying traits: triangular leaves, small curved barbs along the stem, saucer-shaped leaves at stem nodes. In the summer, the plant also has blue fruit.

After confirming the presence of mile-a-minute vine, Forman Orth and Frost said it’s best to put on gloves, rip it out of the ground and leave it to die.

“It’s good for property owners to remove it on their own,” Forman Orth said. “If you can catch it before the fruits develop, you can just pull them out and leave it on site because they are annual plants. Once those blue fruits show up, you need to be more careful.”

If the fruits have developed, the seeds within can help spread the plant. Frost said to try to destroy the seeds if possible and to be careful burning them because they can survive in ashes and sprout when dumped. Once removed, she said to supervise the area where the original vine was pulled to ensure no seeds dropped from the plant.

To report mile-a-minute vine to MDAR, visit bit.ly/3LslfI3.

MDAR also maintains an invasive pest dashboard showing the reported locations of different invasive species at bit.ly/3Wv22vH.

Frost, a Franklin County resident, also said she would be happy to come out and verify mile-a-minute vine sightings. She can be reached at 857-283-8895.

Shelburne invasive plant identification walk

On Sunday, Aug. 11, from 9 to 11 a.m., the Shelburne Open Space Committee and Deerfield River Watershed Association are welcoming the public to join them on a walk to identify various common invasive plant species and learn how to distinguish them from look-alikes. Participants will learn about mile-a-minute vine and other species making their way toward the area, as well as resources directing people to invasive plant control information.

The walk will begin at Mohawk Trail Regional School, 26 Ashfield Road (Route 112). The walk will go around school grounds and off-trail into the woods, so people are encouraged to wear long pants and sturdy shoes. There will be an opportunity to carpool to a nearby site at the end of the walking tour.

For more information or to reserve a spot, email drwa@deerfieldriver.org.

Chris Larabee can be reached at clarabee@recorder.com.