An invasive weed not seen in the United States for six decades has made a mysterious appearance in Minnesota.
Stearns County confirmed the presence of Metaplexis japonica, commonly known as rough potato, a type of vining milkweed that was found along the Lake Wobegon Trail in Holdingford by Sherry Kutter, a University of Minnesota Extension Master Naturalist.
Native to eastern Asia, the weed has not been reported in North America since 1958, when it was found in cornfields near Iowa State University where it was possible used as part of a World War II research project.
"How rough potato arrived in Holdingford is a mystery," Stearns County said in a Friday statement.
Stearns County's agricultural inspector Bob Dunning has been mapping locations of the vines in the county and informing landowners, with the densest infestation reportedly near a baseball field along the South Two River.
"I was surprised by the number of locations I found it in once I began scouting for it," Dunning said.
"I’m grateful to Sherry for discovering this issue before it had become even more widespread. Rough Potato is a very aggressive climber and it has an amazing ability to completely cover other vegetation."
The Stearns County Parks Department, Conservation Corps Minnesota (CCM), and the Minnesota Department of Agriculture (MDA) have started removing thousands of seedpods to prevent their spread.
Further herbicide treatments and manual removal will be conducted over the next several years to further reduce infestations.