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The plant is most easily identified by the purple colour on its stem. (CBC)

People in the B.C. Interior are being told to watch out for giant hogweed, an invasive plant that can cause blisters and blindness.

Heracleum mantegazzianum has already invaded several Lower Mainland communities and parts of Vancouver Island.

The first case of giant hogweed was recently reported in B.C.'s Interior in the tiny West Kootenay community of Hills, north of New Denver. 

Gail Wallin, the executive director of the Invasive Plant Council of B.C., said it proves the plant can thrive in parts of the Interior.

Hills, B.C.


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"It concerns us that this plant has the ability to survive our winters. That means it’s more important for people across B.C. to be aware of it," Wallin said.

"We thought it was the Lower Mainland but even more of British Columbia has to pay attention for the potential of it."

Sap from giant hogweed can cause rashes and blisters on the skin when exposed to sunlight. If the plant's sap gets into a person's eyes, it can cause temporary or permanent blindness.

"There actually have been cases where children have found stalks and because they are hollow, held it up to their eye and have gone blind because of the toxin in their eye," said Jennifer Grenz with the Vancouver Invasive Plant Council.

The plant can be identified by its sheer size — it can grow up to six metres high, with serrated leaves as large as 1.5 metres across, as well as dark reddish-purple blotches on its stalks.

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Giant hogweed can grow to a height of six metres. (CBC)

It produces white clusters of umbrella-like flowers and thrives near streams, creeks, ditches, roads and in vacant lots.

Giant hogweed can easily be confused with other native plants such as cow parsnip or Queen Anne's lace, which also have umbrella-like flowers, but are smaller and do not pose similar health risks.

The hogweed in Hills was ripped out and destroyed. Anyone who comes across giant hogweed is asked to contact the Invasive Plant Council of B.C.