Hogsweed in Pennsylvania

A giant plant that inflicts blisters, second-degree burns, long-term skin damage and blindness on its victims is invading Pennsylvania's Carbon County. And recently, crews from the state's Department of Agriculture will eradicate areas infected with giant hogweed.

"We found eight new sites just last week in Carbon County," said Michael Zeller, from the Department of Agriculture, alarmed at how fast the seeds germinate and shoot up all over road sides and private properties. Wayne and Susquehanna Counties are also on department's list of target areas to track down this devil in disguise. The plant is so dangerous that it is forbidden to plant or cause giant hogweed to grow in the wild, according to the Wildlife and Countryside Act of 1981.

A native of Central Asia, giant hogweed (Hercleum mantegazzianum) was
brought to the United States in the early 20th century as an ornamental
plant for gardens. Its white flowers and characteristic size made it an
attractive plant for gardens. Despite its beauty, the exotic plant
manifests a belligerent bite. Found mostly in state game lands, tree
nurseries and along highways, its hollow stems reach up to 20 feet with
leaves shaped like elephant ears, reaching 5 feet in diameter. The 2- to
4-inch-thick stems are ridged with coarse hairs and purple blotches.

The plant's leaves, seeds, and stems release a clear, watery sap that contains toxins that attack the skin's normal reaction to sunlight. Contact with the skin, followed by sun exposure, causes painful, burning blisters that may develop into purplish or blackish scars. Temporary or even permanent blindness can result if the sap gets into eyes. The sap is actually a defense mechanism against fungal attack. The destructive chemical in the sap is so concentrated, if 1 milligram comes into contact with skin followed by as little as 10 minutes of sunlight, blisters will bubble through the skin.

"Fluids found in the giant hogweed sap are listed on the American Cancer Society's list of known cancer-causing agents," Zeller said. "Every time you get a giant hogweed burn you increase your chance of getting skin cancer."

The plants not only harm humans, but also burn and kill off native plant life. The giants are so hardy and dominant that they take over an area once occupied by native foliage.

Because there are no biological control agents available for giant hogweeds, crews eradicate isolated areas and educate residents on the hazards of the giant and how to identify them. Those who discover hogweeds growing in the area are urged to contact the Department of Agriculture.

Source: Michael Kent