Experts brace for invasion of giant hogweed

The Pennsylvania Department of Agriculture is warning Mercer County residents of a dangerous plant that seems more likely to be found in the pages of a Harry Potter book than in your backyard or along a favorite walking trail.

The giant hogweed plant is listed both as a federal and Pennsylvania noxious weed. The department of agriculture describes the plant as an attractive but dangerous weed that can cause painful burns and sometimes permanent scarring.

The invasive plant is a member of the carrot or parsley family and is native to the Caucasus region of Eurasia. Giant hogweed has been been reported in numerous sites in Crawford and Venango counties, although positive sightings have yet to be confirmed in Mercer County.

“But we know it’s here,” Penn State Master Gardener Coordinator Susan Lanigan said. “Even if it hasn’t been reported yet.”

Lanigan said giant hogweed grows extremely quickly and can grow up to 14 feet tall. It can be identified by numerous small, white flowers found in clusters that can reach more than two feet across. The weed’s stems have purple blotches and coarse, white hairs, and its lobed, incised leaves can grow up to five feet across.

Severe skin irritation occurs when moist skin comes in contact with the plant’s sap and is then exposed to sunlight.

Lanigan said symptoms can take up to two days to appear after contact.

“Most people probably wouldn’t even realize (they came in contact with the sap) until after the fact,” Lanigan said.

But a tall, white flowering plant with a purple stem is not necessarily proof enough of a giant hogweed invasion. Lanigan mentioned three other “imposter” plants are commonly mistaken for the dangerous weed.

Cow parsnip and angelica are two harmless lookalikes that grow smaller but are similar in appearance to a giant hogweed plant.

Lanigan said poison hemlock, which is only toxic if ingested, has also been mistaken for giant hogweed.

But Lanigan said if you are unsure, it’s best to play it safe and call the experts at the Pennsylvania Department of Agriculture’s Giant Hogweed Hotline.

“Call even if you are a little suspect,” Lanigan said, “just to make sure no one ends up getting hurt.”

THE Hogweed Hotline can be reached at 1-877-464-9333. Callers will be asked to leave a daytime phone number and will be contacted within a couple of days.