The giant hogweed, a 10-foot tall plant native to the land between the Black and Caspian seas in eastern Europe, was recently spotted in Virginia. 30 plants were discovered in Clarke County, and officials believe this invasive plant could spread to other counties and the coastal area. Virginia Tech's Massey Herbarium reported this is the first time the plant has been spotted in the state.
The massive plant looks a little like Queen Anne's lace but on a much bigger scale. The stems can be two to four inches thick and its flowers can grow to two and a half feet in diameter. The leaves are enormous — as much as five feet wide.
The sap of giant hogweed (Heracleum mantegazzianum) can "cause severe skin and eye irritation, painful blistering, permanent scarring and blindness," according to the New York Department of Environmental Conservation or DEC.
First brought to the United States in the 19th century as a garden ornament, hogweed has since spread to 11 states, including Pennsylvania, Washington, Vermont and Maine. This invasive plant is most prevalent in New York's Oneida County, according to the New York DEC, with large clusters in Niagara, Orleans, Ontario and Cayuga counties. In 2011, there were 1,004 confirmed sightings in New York.
Touching a hogweed plant might not cause you immediate discomfort, but its sap reacts strongly to sunlight. "You end up with third-degree burns, oozing and scars," Naja Kraus, giant hogweed program coordinator for the DEC, said in a 2011 press statement, quoted by LiveScience. "If it gets in your eyes, you can go blind." According to a hogweed fact sheet published by Ohio State University, "Furocoumarins in the sap can cause a skin reaction known as phyto-photodermatitis. This causes the skin to be highly sensitive to ultraviolet light."
The New York DEC has an online identification guide that compares the plant to several look-alike species. They have also published some rather graphic photos of hogweed injuries, along with safety precautions to take if you think you have encountered the plant.
Giant hogweed is one of the many plants on the Federal Invasive and Noxious Weeds list. It is illegal to grow, sell or transport the plant because of the threats it poses to human health and native species, which can be crowded out when hogweed takes root in an area.
The U.S. isn't the only country with an invasive hogweed problem. The plant was also observed in Guelph, Ontario.
Editor's note: This article has been updated since it was originally posted in July 2011.