The Direction de Santé Publique de la Montérégie (DSPM) recently issued a warning concerning the presence of giant hogweed, a large plant with a white umbrella-shaped flower that, while attractive, can cause severe burns when picked.
The stem contains a toxic sap that reacts strongly to sunlight, making exposed skin extremely sensitive to the sun. The reaction, which is like a burn, is very painful. The DSPM suggests that while very few cases of human exposure to the toxic sap have been reported, it is important to be cautious around this invasive plant.
A more prevalent issue in the region is the spread of wild parsnip, an invasive plant in the same family as giant hogweed, that can produce similar burns when skin is exposed to its sap. “The plant is currently in full bloom, and it is easily distinguished by its size and its yellow flowers,” says Catherine Turgeon, the Union des Producteurs Agricole advisor for the Haut-Saint-Laurent syndicate. The plants can grow up to 1.5 metres tall, with umbrella-shaped flower clusters that are 10 to 20 centimetres across.
The plant is especially present along rural roads and in ditches. The Haut-Saint-Laurent syndicate adopted a resolution in 2016 requesting that the Ministry of Transport, as well as the municipalities and the MRC du Haut-Saint-Laurent, work to limit the spread of the plant by coordinating mowing activities to avoid the spread of seeds. The resolution also calls for the creation and implementation of an eradication plan for wild parsnip. Given the continued spread of the plant, there is more to be done. “It really is everywhere,” Turgeon says, noting contact with the sap causes severe dermatitis “and the scars are significant.”
Should skin contact occur with the sap of either giant hogweed or wild parsnip, it is important to remove the sap as quickly as possible. Use absorbent paper without rubbing and wash the affected area with soap and water. A giant hogweed or wild parsnip burn should not be exposed to sunlight for at least a week. Contact Info-Santé (811) or the Quebec Poison Control Centre at 1-800-463-5060 for information on treating this type of burn. (SR)