Printer-friendlyGiant Hogweed
Do Not Touch This Plant!
Giant Hogweed can grow to 12 feet or more
Giant hogweed (Heracleum mantegazzianum) is a Federally listed noxious weed. Its sap, in combination with moisture and sunlight, can cause severe skin and eye irritation, painful blistering, permanent scarring and blindness. Contact between the skin and the sap of this plant occurs either through brushing against the bristles on the stem or breaking the stem or leaves. This plant poses a serious health threat; see your physician if you think you have been burned by giant hogweed. If you think you have giant hogweed on your property, do NOT touch it.
Use the information and links on this webpage to confirm whether the plant in question is or is not giant hogweed. Some other plants look very similar. If you need additional information or assistance in identifying your plant, you may call us at 518-402-9425. You will be asked to describe the plant height, stem color, leaf shape, flower color and shape, as well as give directions to the plant site. If you can take digital photos and email them to us, it would help us identify your plant.
Description
Giant hogweed is a biennial or perennial herb in the carrot family (Apiaceae) which can grow to 12 feet or more. Its hollow, ridged stems grow 2-4 inches in diameter and have dark reddish-purple blotches. Its large compound leaves can grow up to 5 feet wide. It's white flower heads can grow up to 2 1/2 feet in diameter.
Giant hogweed is an aggressive competitor. Because of its size and rapid growth, it out-competes native plant species. Giant hogweed dies back during the winter months, leaving bare ground that can lead to an increase in soil erosion on riverbanks and steep slopes.
Distribution
Giant hogweed is a native of the Caucasus Mountain region between the Black and Caspian Seas. It was introduced to Europe and the United Kingdom in the late nineteenth century and to the United States in the early twentieth century as an ornamental garden plant. It has become established in New York, Pennsylvania, Ohio, Maryland, Oregon, Washington, Michigan, Virginia, Vermont, New Hampshire and Maine. Dried fruits may be imported as a spice or food called golpar. Seeds may also be distributed by birds and waterways, and can remain viable for over 10 years.
Habitat
Wet areas, along streams and rivers; naturalized on waste ground, near houses, in vacant lots, along railways and roads. It prefers moist soil and can quickly dominate ravines and stream banks.
More about Giant Hogweed:
- Giant Hogweed Statewide Distribution Map - Statewide distribution and density of giant hogweed sites by county.
- Giant Hogweed Identification Key - Key to help identify this weed.
