Giant Hogweed (also known as giant cow parsnip) is a member of the Umbelliferae family of aromatic plants. It is a perennial plant native to Asia. Giant Hogweed flowers from late spring to mid summer, with numerous white flowers.

Each of these plants can produce up to 100,000 seeds. The seds can remain viable in the soil for up to seven years.

Giant hogweed plants grow up to 5 metres in height with a purple-spotted, hollow green bristly stem. The leaves are dark green, coarsely toothed and can exceed 2.5 metres in length at the base of the plant.

Giant hogweed is a phototoxic plant. It has clear, watery sap which contains toxins that cause photodermatitis. Skin contact, followed by exposure to sunlight, produces painful burning blisters.

The sap of giant hogweed can also cause temporary or permanent blindness following eye contact. If you come in contact with giant hogweed sap, wash the area immediately with soap and water, avoid sunlight exposure for several days and seek medical attention.

Helpful Links:

www.ontarioweeds.com

www.invadingspecies.com