Around 30 noxious Hogweed have been found in Virginia

Scientists and officials on the East Coast are working to locate invasive plants known as giant hogweed that can cause third-degree burns and even permanent blindness to those who come in contact, after Virginia residents reported discovering the noxious plants in their yards.

Giant hogweed looks very similar to the common native species cow parsnip, but if the hogweed's sap touches the skin it can cause chronic, burning pain that can last several weeks, according to experts at Virginia Tech University's Massey Herbarium.

“Once you get the sap on your skin, and you are exposed to the sunlight, the chemical is activated [and] it can cause a severe burn,” Massey Herbarium curator Jordan Metzgar told ABC News.

Giant hogweed and cow parsnip have “similar flowers and leaves" and cow parsnip's "sap can cause [a] reaction, but usually it is not as bad as hogweed,” he added.

Hogweed was first planted about 30 or 40 years ago, Metzger said.

The first plants reported last week were part of a home garden and had been on the property for forty years, according to Kevin Heffernan, a stewardship biologist at the Virginia Department of Conservation and Recreation.

“It is not escaped and naturalized in our landscape,” Mr. Heffernan told ABC. “However, in this instance, it was a cultivated planting, not a wild population. This is a very important distinction.”

Giant hogweed is listed in Virginia by the Department of Agriculture and Consumer Services (VDACS) as a "noxious weed,’ and by the Department of Conservation and Recreation (DCR) as “an early detection invasive plant,” which means it is not yet entrenched in Virginia, Heffernan said.

"If we find it the goal is to eradicate it before it becomes established,” he told ABC News.

The plants that were discovered in Clarke County last week are being removed by VDACS.

The group has identified about 30 toxic hogweed plants in Virginia so far.

“A species will continue to be listed as "early detection" until it is shown to be permanently established and beyond the scope of a feasible eradication program,” DCR wrote on its website. “Further, if a species is successfully eradicated, it will likely remain on the early detection list to encourage ongoing vigilance.”

Metzgar said that if anyone makes contact with giant hogweed, the victim should wash the sap off of the skin with cold water and soap. Victims would needs a few weeks to recover from the burn, and their skin would remain sensitive to sunlight.

“No one knew about this plant before," Metzger said. "Sounds like they actually planted it about 30 or 40 years ago as a decorative species, but nobody knew they were there until just now.”

Metzgar said that his department has been talking to the press to spread the news of the danger that can be caused by giant hogweed.

“Since last Wednesday, I have been responding to email and phone messages from concerned citizens," he said. "I am sharing with them the information I have shared with you,” Heffernan said.

New York’s Department of Environmental Conservation has also published a guide on “how to control giant hogweed,” on its website.