The Plant Nightmares are Made of

giant hogweed skin reactions

Giant Hogweed ( Heracleum mantegazzianum ), also known as giant cow parsley was first introduced to the United States in the early twentieth century. The plant originates from the Caucasas mountain region and southwestern Asia. This nightmare of a plant should not be messed with. In fact, if you see this plant you are to report it to your local extension office immediately. Furthermore the plant has been classified under the federal noxious weed protection act. Furthermore it is illegal to transport, sell, or relocate the plants within the United States.

Several reports in the last couple years have surfaced around the media and internet about giant hogweed. People have experienced up to third degree burns on their skin after coming in contact with the plants sap and then being exposed to ultraviolet light. Here we will take a closer look at the plant, along with how it reacts on your skin.

Description of Giant Hogweed

Falling into the perennial class, giant hogweed can be easily recognized by its massive size. Standard heights reaching up to 20ft tall, the plant sends out large dense canopies which will out compete local native plants. Hogweed has stout reddish purple stems and stalk. Stems, and stalks will be hollow and range in size from 2-4 inches in diameter.

Flower sets on this plant will seem massive as well. In fact they can reach up to 2.5 feet in diameter. The flowers closely resemble queen anne’s lace, or even the dreaded poison hemlock.

Skin contact from Giant Hogweed

Giant hogweed exudes a clear liquid sap which should never be exposed to human skin. The sap from the plant is phototoxic . Meaning it is a chemically induced skin irritation, requiring light, that does not involve the immune system.

For images and further details on giant hogweed department of environmental conservation website


Washington State Noxious Weed Control Board

New York State Department of Environmental Conservation

US Department of Agriculture


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