Even though a lot of people have a difficult time identifying poison ivy, poison oak or sumac, the itchy rash that appears on the skin is well known. Wild parsnip and giant hogweed are two more toxic plants that can produce a reaction, but unlike poison ivy, these two plants contain a sap that can cause severe burn blisters on exposed skin. These are two plants pet owners should be able to identify.
Most of us haven’t the foggiest idea about the types of plants we encounter while hiking along a sunny trail or wandering through a field with a dog. Plants with pretty flowers seem safe and some people can’t resist picking a bouquet as they walk. Even if you don’t pick flowers, just walking through a patch of wild parsnip or giant hogweed can produce burns if your skin comes in contact with the sap. Pets are at risk if they run through a patch and get sap on their nose or in their eyes. It’s also possible for the juice to work its way down to the skin of short-haired dogs, and like poison ivy, if a dog or cat has sap on his coat he can transfer it to you if you pet him.
This invasive plant is native to Europe and Asia and was brought to the United States by immigrants who cultivated the plant for its edible root. It can be found throughout most of the United States except Hawaii, Georgia, Alabama, Mississippi and Florida. A member of the Umbelliferae family which includes carrots, celery, parsnip, parsley and Queen Anne’s Lace, wild parsnip is a biennial/perennial herb that smells similar to the garden variety parsnip.
Sometimes referred to as poison parsnip, the toxic sap can be found in the plant’s small five-petal yellow flowers that grow in an umbrella-like pattern, as well as in the fruit, jagged leaves and hairy hollow stem. Wild parsnip can grow up to five feet high with leaves that resemble celery leaves. It’s found along roadways, in ditches, pastures, abandoned fields, on restored prairie land, and disturbed areas. It’s often mistaken for Queen Anne’s lace which has white flowers.
The sap contains chemical compounds which causes a reaction called phytophotodermatitis when the sap is absorbed into the skin. The chemicals are activated by ultraviolet light from the sun, even on cloudy days, and breaks down skin tissue and cells causing burns and blistering within 24 to 48 hours. Sometimes a burned area of skin will turn dark red or brown and stay that way for up to two years. Sweating can speed up the absorption of the chemicals. Burns may appear in a splatter formation or streaks on the skin which indicates where a leaf or stem was dragged across the skin. If sap gets into the eyes, it can cause temporary or permanent blindness in humans and pets.
Another invasive plant, giant hogweed is native to the Caucasus Mountain region of Eurasia. It showed up in the New York area in 1917, most likely as an ornamental plant because of its beautiful white flowers and large size. This toxic weed has been described as “wild parsnip on steroids.” Also a member of the carrot family, it’s a huge plant that can grow up to 14 feet, has thick leaves up to 5 feet wide and large clusters of white flat-topped flowers that grow in an umbrella-like pattern. The hollow green stem is dotted with purple splotches and coarse white hairs grow along it.
Giant hogweed can be found in meadows, along roadways, stream and river banks, in fields, forests and yards. Thankfully this plant isn’t as widespread as wild parsnip…yet. So far, it’s been found in WA, OR, IL, WI, IN, OH, MI, NC, PA, NY, MD, NJ, VT, NH, CT, MA and ME. Listed as a federal noxious weed, states are destroying giant hogweed when they find it, but it’s tenacious and continues to slowly creep into new areas. A reaction from giant hogweed can begin within 15 minutes.
If you get sap from either of these plants on your skin, wash the affected area immediately with soap and cold water. Stay out of the sunlight for 48 hours because it can take several days for a reaction to occur. Apply sunscreen to affected areas if you can’t stay out of the sun.
Like any living organism, plants have ways of protecting themselves. Wild parsnip and giant hogweed release toxic sap as a defense. Essentially, the chemical makeup of the sap prevents the skin from protecting itself from the sun.
Pet owners need to beware of these plants. Dogs and outside cats can be affected and they can transfer sap to you if there’s any on their coat. Know how to identify wild parsnip and giant hogweed so you and your pets can give these plants a wide berth.
Read more articles by Linda Cole
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