Factor in Forewarning
Painful blistering caused by contact with giant hogweed.
Giant hogweed, Heracleum mantegazzianum, is federally listed as a noxious weed, it is invasive and potentially very harmful to humans; contact with this plant is highly discouraged. The sap of this plant, when combined with moisture and sunlight, can cause severe skin and eye irritation, painful blistering and possibly blindness and/or permanent scarring. While attempts at controlling this invasive, noxious weed state agencies advise learning to identify, avoid and report any specimens found.
Identifying Instances
Giant hogweed is a perennial herb in the carrot family, Apiaceae. It can grow up to upwards of 14 feet tall. Its hollow, ridged stems are 2 to 4 inches in diameter and can have dark, reddish blotches. Compound leaves can be up to 5 feet wide and white blooms can get up to 2 1/2 feet in diameter. Unfortunately, this invasive species initially introduced from Europe is now established in 12 states including Massachusetts, New York, Connecticut and Pennsylvania.
Giant hogweed can grow to over 14 feet tall with large, umbrella shaped flower clusters bearing 50 to 150 flower rays.
Stems become blotched with reddish spots, and bear coarse, white hairs at the base of leaf stalks.
Agree to Action
If you think you have found giant hogweed on your property or elsewhere, do not touch it, but attempt to make a positive identification, this key may prove helpful http://www.dec.ny.gov/animals/72766.html. Next, from a safe distance, take photos (preferably high resolution, if possible) of the leaves, stem, flowers and seeds. Then contact your arborist for assistance, and/or, email your photos and a detailed description of the specimen and the habitat in which it was found to your state’s conservation or environmental department. If giant hogweed is actually found on your property, your state’s environmental agency may need require access and will need to develop a management plan.
IF you have already come into contact with giant hogweed, or just suspect you may have, immediately wash the affected area with soap and water and avoid the sun for 48 hours. Seek your physician’s advice as soon as possible, this plant can pose a serious health threat.
