A Fiery Plant to Avoid: Wild Parsnip

Originally published in The Living Land column in The Hawk Eye on May 27, 2016.

As much as I love encouraging everyone to go play outside in nature as much as possible, today’s story is a cautionary tale.

If you ask most people what to beware of outdoors the typical responses are generally snakes, spiders, ticks and other bugs. Outside of the animal kingdom, it’s usually the three “poison” plants, meaning poison ivy, oak or sumac. Sometimes stinging nettle comes up. Certainly those are all things to avoid but there’s another sinister plant to watch for that seldom gets the recognition it deserves. In fact, I’d venture to guess most folks reading this today could not identify the plant, assuming they’ve even heard of it.

It’s called wild parsnip. And it should be avoided as if it were fire. It contains a chemical that reacts with sunlight and causes serious, localized burns if it gets on exposed skin. Some burns can be so severe that they blister and can cause skin discoloration for years after the blister has healed.
Scientifically known as Pastinaca sativa, wild parsnip is a non-native invasive plant originally from Europe and Asia that has more or less naturalized to our area now. After spending one or more years in the rosette stage, it grows on stout, grooved stalks to heights of four feet or so and blooms throughout the summer with numerous flat-topped, umbrella-like yellow flower clusters two to six inches wide. It kind of looks like a scraggly, yellow-flowered version of Queen Anne’s lace. It’s not nearly as pretty as most prairie flowers but it really likes sites such as road ditches, old fields, pastures, forest edges and prairies in the early stages of restoration where its height and color make it stand out. It may be tempting to pick, especially for children, but the consequences of doing so are no fun.

The chemicals in wild parsnip are called psoralens. When they come in contact with our skin, these chemicals absorb energy from ultraviolet light and bind to cell membranes, chemically destroying the skin cells. It’s literally a chemical burn, though dermatologists technically call it phytophotodermatitis. The process does take some time so often symptoms don’t arise until later in the day or even the day after contact. And though it does require UV light to energize the reaction, such wavelengths are present even on cloudy days.

Mild cases of wild parsnip burns result in localized reddened skin that feels like a sunburn. In worse cases, the skin will blister. Victims of severe cases can develop large blisters over large areas. Some have described such cases as looking like they’ve been sprayed with acid. Instances of such cases often arise after mowing or string trimming areas with rampant wild parsnip invasions without wearing protective clothing. Others, including many children, have been exposed to the chemicals after picking or pulling the plants or by walking or playing in areas where it is present. Since parsnip burns generally appear in streaks and spots, they’re often misdiagnosed and treated as poison ivy rashes.

Avoiding wild parsnip is the best way to prevent getting burned by the plant. Learn to identify it and steer clear of areas where it is present. As with most non-native invasive species, it tends to spread widely. If you notice one fully grown plant, there are probably many others lurking around though they may still be in the rosette stage close to the ground. They should all be avoided.

If you’re likely to find yourself in areas where wild parsnip may lurk, wear long sleeves and pants and closed-toed shoes. The psoralens need UV light to react so limiting sun exposure will help prevent burns. Wild parsnip removal efforts are often done very early or late in the day when sun exposure is minimal. Thoroughly washing with soap and cold water after any romp in the wild is also a good idea. Doing so will remove not just wild parsnip juices but also poison ivy oils and other plant chemicals that may have been picked up during the outing. Cold water is best as it will keep skin pores closed and minimize absorption of plant oils.

If you do find yourself with a parsnip burn, treat it as you would any other burn. Cover the affected area with a cool, wet cloth to relieve the symptoms. If blisters occur, leave them alone as long as possible. After they rupture, leave the remaining skin in place to serve as a natural bandage. Keep the area clean and use an antibiotic ointment to prevent infection. Bandage loosely. In serious cases, contact your doctor.

So as you take to the trails and fields this summer, don’t get burned. Learn how to identify and avoid wild parsnip and other skin-irritating plants. Because nothing ruins a fun day outside like a case of phytophotodermatitis.