Toxic and noxious weed growing in Tyendinaga

The highly toxic Giant Hogweed has been spotted growing in abundance in Tyendinaga. The Hogweed is located at Beach Road as it turns into Ridge Road on the Tyendinaga Mohawk Territory. In the monthly Mohawks of the Bay of Quinte (MBQ) newsletter community members have been advised to stay away from the area and more importantly stay away from the plant.

The MBQ Newsletter provides step by step directions should anyone get come into contact with this noxious weed. First, if exposed to the clear watery sap, wrap up the affected area to block out sunlight as sunlight triggers the toxins. Next, wash off the sap with soapy hot water as soon as possible. You cannot expose the affected area to sunlight for at least 48 hours, it must be kept covered. Should the affected area be exposed and a rash appears seek immediate medical attention.

Hogweed produces a chemical-like sap that can result in phytophotodermatitis in humans. Ontario Invading Species Awareness Program’s (OISAP) website informs us, “The clear watery sap of Giant Hogweed contains toxins that can cause severe burns if you get the sap on your skin and the skin is then exposed to sunlight. Symptoms ensue within 48 hours and comprise of painful blisters.” They go on to say that, although, some websites have reported permanent blindness when coming into contact with your eyes, there is no research to back that up.

The OISAP website also states that the giant hogweed is otherwise known as “Giant Cow Parsnip” and it has umbrella-shaped flowers liken to Queen Anne Lace. You can identify this plant by its sharp edge leaves and firm green stem which is striped with dark red. White coarse hair also grows to the base of the stem. OISAP goes on to say that as a perennial it blooms in late spring and mid-summer and is a member of the carrot family. It is indigenous to southwest Asia, however it has been acclimatizing in North America and is more commonly seen in Southern and central Ontario. Like any invasive weed it spreads and grows quickly on roadsides, in ditches and by streams usually by old fields and/or open woodlands.

MNR website asks, “If you see Giant Hogweed on your property or your community please call the Invading Species Hotline at 1-800-563-7711 or report it at You will be asked to send in photos for identification. Do not collect parts of the plant for identification.” If you live on a reserve call your local band office to have it sprayed with pesticide.

Despite its toxicity to humans the plant does have some positive uses. In Europe and Asia it is used as an ornamental in gardens reports OISAP, or ground up and used as a spice for some Iranian dishes. The weed is not toxic to livestock and thus has some nutritional value for animals. Rita Merete Butten Schon and Charlotte Nielson, in their article edited in Ecology and Management of Giant Hogweed discuss the nutritional value of the Giant Hogweed stating it is greater than or equal to hay, grass, maize silage, sugar beets and turnips. It is readily digestible as three quarters of the dry matter is a water-soluble carbohydrate, it also contains crude protein and fat. It would seem one species’ burn is another species’ supper.

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