CALHOUN COUNTY, Mich. – An invasive mile-a-minute weed (Persicaria perfoliata) has been found at Albion College’s Whitehouse Nature Center in Calhoun County, officials said.
It’s a fast-growing, barbed vine that’s native tin India, Asia and the Philippine Islands. It was not known to be in Michigan until it was discovered by Doug White, a professor of ecology at Albion College on Oct. 3. It was growing in a forest opening on the property.
“I’m not normally out there in October, but we color-banded nestlings this year, and I was following the fledglings,” said White. “I saw these purple and blue fruits on a plant, and I was curious. Years ago, I wrote my dissertation on bird-dispersed fruits, so naturally I wanted to find out what they were.”
White took photos, plucked a branch from the vine and after some researcher discovered it was an invasive plant previously unknown in the state.
What is mile-a-minute weed?
Mile-a-minute weed is an annual vine that can grow up to 6 inches per day, or 25 feet in 6 to 8 weeks. Its light green leaves are shaped like equilateral triangles, and both the stems and leaf blades are lined with small, recurved barbs that help it climb over other vegetation.
It thrives in full sun and wet soils, but can grow in a variety of conditions. It could do damage to roadsides, steam banks, forest edges and fence lines.
It is a problem because of its fast growth and climbing habit. Those factors allow it to overtake native and landscape vegetation.
Mile-a-minute weed infestations have been reported in 15 states across the United States. The closest known infestation is in northern Ohio.
While mine-a-minute weed can be removed by hand, seeds can persist in the soil for up to six years. Infested sites need to be monitored regularly.