The wild parsnip is in bloom in across Minnesota, making it easy to spot this time of year. The wildflower may be pretty, but touch it with bare skin and you'll get painful blisters.
State DNR officials and conservation groups are trying to remove the invasive plant in parts of southeastern Minnesota, where it is especially prevalent.
Thousands of wild parsnip plants cover a field at Frontenac State Park earlier this week. Each plant is a couple feet tall. Its flowers cluster atop a single stalk, like a bright, yellow umbrella.
"A lot of people when they're driving down the highway, they think 'oh, look at the pretty yellow flowers.' Turns out this stuff can actually be pretty vicious," said Karl Erie, a volunteer with Conservation Corp MN. "It burns, it itches, it blisters. It's truly a trifecta."
What makes the wild parsnip so vicious is the toxic sap in its stalk and flowers. It causes a chemical reaction when it comes in contact with skin and is then exposed to sunlight. The blisters and discoloration can last several years.
That's why Erie and a group of volunteers with Conservation Corp MN are here pulling these plants out of the ground. They wear long-sleeved shirts, tall boots and gloves to avoid touching the plant with their skin.
Volunteer Sean McMullen uses a shovel to sever the plant from its root so it won't grow back again. The plant smells like a carrot when he pulls it out of the ground. Altogether, the group will pull about 2,000 to 3,000 plants a day.
"When the grass gets as high as the parsnip plant, it's hard to get to the base of the plant to put a shovel under it to pull the plant up," McMullen said. "We like it when the grass is nice and short like this."
The timing of their work is important because within days, all the yellow flowerheads will become seeds and continue the plant's spread.
Officials with the Minnesota Department of Natural Resources say the wild parsnip population continues to grow in the state, especially in southeastern Minnesota.
Much like other invasive plants, such as buckthorn, garlic mustard, purple loosestrife, and spotted knapweed, the wild parsnip spreads quickly, said Amy Poss, a buildings and ground worker at Frontenac.
"We have started putting up signs about it because of the blistering effect," Poss said. "We definitely keep it off of trails. We don't want it where people can handle it because the oil will cause heavy blistering in the sun."
Poss said park employees have tried to manage the spread of wild parsnip for about five years, but she said most hikers and visitors are unaware of the plant's painful dangers. Lots of people know they should stay away from poison ivy. Poss said her first hand experience with wild parsnip taught her a lesson.
"It seems to me, worse than poison ivy," Poss said. "I myself have had it a little bit on my hands and it was like every time for three years when I got in the sun, it would come back out as small blisters on my hands that itched very badly."
Wild parsnip is native to Europe and Asia. It arrived in the U.S. more than 100 years ago.
Laura Van Riper, terrestrial and invasive species coordinator for the DNR's Division of Ecological and Water Resources, specializes in invasive species. She said not only is the parsnip painful to humans, but it also threatens native plant species.
"When you get a dense monoculture of wild parsnip you're not getting much else at that site," Van Riper said. "It can be a challenge to restore those areas to try to get more species growing there."
She said wild parsnip is not as aggressive as other invasive plants and won't completely take over healthy native prairie areas.
"But we have a lot of land that has been disturbed for roadsides or is heavily grazed or was tilled in the past and is now an older field. And in those types of areas, this wild parsnip can really spread rapidly."
As summer gets underway, Van Riper cautions hikers and campers to stay on trails and stay away from those tall, yellow plants.