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By Lynda Jensen
Editor
There is an invader in Wright County ditches spreading along the Highway 12 corridor and railways, causing grave concern for Wright County Soil and Water.
The invader is a weed called wild parsnip, which causes severe burns when the juice or pollen comes into contact with human skin in combination with ultra violet rays, commented Joe Jacobs of Wright County Soil and Water.
From there, the wound turns into “super pigmentation,” which looks like a dark suntan that lasts for four to six months, Jacobs said.
The weed, which has yellow flowers (click here to see photo), is a biennial that can be spread by mowing, and appears to be moving along state highways and along railroad tracks – with a severe infestation between Howard Lake and Waverly; although the weeds have been found along Highway 12 all the way to Dassel, Jacobs said. Click here to see map of infestation.
“Once it gets a foothold, it will be impossible to get it out,” Jacobs said. “We have a short window to work with.”
The only way to get rid of it is to cut the plant at the roots or use herbicide, he said.
Trying to control the weed will take a coordinated effort amongst townships, cities, the railroad, county, Department of Transportation and private landowners, Jacobs said.
The weed itself is not classified as a noxious weed, but rather an invasive species, Jacobs noted.
As a biennual, it blooms every two years, with the first year showing a plant that stands about six inches to just over a foot in height. The following year, it stands on a tall stalk, and can reach heights up to four or five feet, Jacobs said.
More information about wild parsnip
The following is information about wild parsnip from the Wisconsin Department of Natural Resources.
The scientific name for wild parsnip (in Latin) is pastinaca sativa.
Its original homeland is Europe and Asia.
Its arrival date was detected in Wright County about six years ago, but has gained momentum in recent years.
No one is quite sure when this plant arrived in the US, and whether someone brought it to this country on purpose or whether it hitched a ride as seed with an immigrant.
There are records of this plant in Wisconsin from as early as 1894 – more than 100 years ago.
Its invasive terrority covers all of Wisconsin, in open habitat – along roadsides, in abandoned fields, and prairies.
It is an aggressive plant and once it gets established will spread rapidly. It doesn’t like shade.
How to identify wild parsnip:
Wild parsnip is a member of the carrot family. It spends its first summer as a rosette of leaves fairly close to the ground. The plant is anchored in place by a long, thick taproot. When conditions are right – usually in its second summer – it sends up a single flower stalk that holds hundreds of yellow flowers in flat-topped, umbrella-like clusters called umbels. The flower stalks can grow to be more than four feet tall.
Don’t be fooled by look-alikes because there is at least one other plant that looks similar to wild parsnip – prairie parsley, a native prairie species listed as threatened in Wisconsin.
Wild parsnip is one of a few, unique plants that can cause phyto-photo-dermatitis.
What this means is that chemicals in the juices of this plant with the help of ultraviolet light can burn your skin. These chemicals are found in the green leaves, stems and fruits of wild parsnip.
The chemicals in the plant that cause this problem are called furocoumarins.
When absorbed by your skin, they’re energized by ultraviolet light, causing a breakdown of cells and skin tissue.
This leaves you with a red, sunburn-like area. (Don’t think you’re safe on a cloudy day – you can still get burned since ultraviolet light is present even on cloudy days.)
Once exposed, your skin will turn red within 24 to 48 hours. In many cases, after the skin reddens, blisters appear – some of them pretty big.
Sometimes the area that was burned takes on a dark red or brown discoloration that can last for as long as two years.
Parsnip burns often appear as streaks and long spots. It shows up where a juicy leaf or stem dragged across the skin before exposure to the sun. The good news is, while it might hurt for awhile, the burning feeling will go away in a day or two.
This is different from poison ivy where the itching can last for weeks.
Controlling wild parsnip
The best way to get rid of wild parsnip is by finding it early in its invasion when there aren’t many plants. Cutting the root of each plant just below ground level can help stop the spread.
This can be done with a dandelion-digging fork, a sharp shovel or spade. If the population is large, a power brush-cutter is sometimes used.
Regular mowing, or grazing by cows, keeps wild parsnip from flowering and making seeds.
If you’re going to be near this invader, be sure to wear gloves, long-sleeved shirt, and pants.
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