Giant Hogweed Warning: Plant That Can Cause Blindness, Burn Skin, Spreads Into New State

Officials have warned the public against touching giant hogweed, which can burn the skin and cause blindness, after it was spotted for the first time in Virginia.

Also known as Heracleum mantegazzianum, giant hogweed has a clear, watery sap which can burn the skin and cause painful blistering when combined with moisture and sunlight. The resulting blisters can cause permanent scarring. This process, known as phytophotodermatitis, happens when the sap makes the skin more sensitive to sunlight.

Even after the blisters have healed, the skin can remain sensitive to light for many years, officials in Virginia warned.

On Wednesday, the Isle of Wight County, Virginia, issued a safety alert after announcing the giant hogweed had been found in the state.

"Giant hogweed makes poison ivy look like a walk in the park," officials warned on the Isle of Wight County Virginia Facebook page.

The Massey Herbarium at Virginia Tech, which researches the state's flora, confirmed it had identified the first giant hogweed population in Clark County.

Officials stressed that giant hogweed must only be handled while wearing protective clothing such as eye protection, coveralls and rubber gloves. The plant should not be mown or cut using mechanical equipment, as it could expose skin to the sap, and a new plant would regrow unless its roots were removed. It must be disposed of using heavy-duty garbage bags.

Blisters can form within 48 hours of touching the plant. Those whose skin comes into contact with giant hogweed are advised to wash the area with soap and cold water as soon as possible, and protect it from sunlight for 48 hours. If it enters the eyes, they should be rinsed with water, and sunglasses should be worn. Anyone who has a reaction to the plant should visit a physician, according to New York state.

The plant has been put on the Virginia invasive plants early detection species list, meaning that while it does not grow widely in the state, it has been known to thrive in similar habitats. Members of the public who spot the plant are asked to contact the Virginia Department of Conservation and Recreation.

Giant hogweed has been found in the Pacific Northwest and the northeastern states of New York, Massachusetts, Maine, Pennsylvania and Connecticut. It has also been reported in one country in North Carolina, according to the Virginia invasive species register.

The federal government has listed the plant as a noxious weed, alongside the states of Alabama, California, Connecticut, Florida, Massachusetts, Minnesota, New Hampshire, North Carolina, Oregon, Pennsylvania, South Carolina, Vermont and Washington.

A perennial herb, giant hogweed originated in the western Caucasus Mountains in West Asia, and is believed to have spread around the world by collectors working for botanical gardens. It can grow up to 14 feet or more and is a member of the carrot family.