Be careful before you pick that pretty wildflower. Giant hogweed, which can grow up to twenty-feet-tall and produce attractive white flowers, is a beautiful but dangerous plant. The plant produces a clear sap capable of causing third-degree burns or even blindness in humans who touch it. Native to the Caucasus in Central Asia, giant hogweed has become a wide-ranging invasive species in the Northern United States, Southern Canada, and Western Europe. Those who encounter the toxic flora are advised to admire from a distance.
Like Japanese knotweed and other invasive, noxious plant species, giant hogweed was first introduced to the United Kingdom and other countries as an ornamental plant. Its white flowers reveal its familial origins as a member of the carrot family, like its similar though diminutive and less-toxic relative known as Queen Anne’s Lace. Hogweed flowers can be up to two feet across and are popular among pollinators.
Hogweed’s curse is its phototoxic sap, which causes skin, eyes or whatever it touches to become highly sensitive to UV light. If the affected skin is exposed to sunlight, it can quickly become red and irritated. Affected areas will rapidly deteriorate if exposure is continued and the sap is not washed off. In North America, giant hogweed usually blooms in July. If possible, it is important to eliminate the plants before they flower and reproduce. “You want to have it eradicated before it does go to seed,” said Barbara Ashey, Town Administrator for Northport, Maine. “There are thousands of these seeds.” On the bright side, pigs and cows seem able to consume giant hogweed without harm and may be used as a biocontrol solution in the fight against the invasive species.