'Nasty' plant whose sap causes 3rd-degree burns could jump into Alberta, group warns

Albertans are being urged to watch out for a plant with a toxic sap that can cause third-degree burns when exposed to sunlight and even blindness if it gets in the eyes.

Nature Conservancy of Canada is encouraging Albertans to report sightings of giant hogweed

Hogweed has a toxic sap that can cause third-degree burns when exposed to sunlight and even blindness if it gets in the eyes. (Meghan Grguric/University of Guelph)

It's called giant hogweed and it doesn't play nice with humans.

The elegant yet dangerous plant is just one of a number of invasive species that the Nature Conservancy of Canada wants Albertans to look out for this summer.

Giant hogweed is found in British Columbia, and there's a risk it could find its way into Alberta.

Early detection could stop the plant from spreading across the border, said Kristyn Ferguson, the agency's conservation scientist and a program director, on the Calgary Eyeopener.

"I encourage people if you do see it to report it … because if you don't have it yet, you have a chance to get a hold of it before it becomes a big problem in Alberta," Ferguson said.

Each giant hogweed plant produce tens of thousands of seeds, which can be carried by either the wind or water. Seeds dropped in water can float for up to three days, and on dry land, they're viable for up to 15 years. (Meghan Grguric/University of Guelph)

Giant hogweed can grow to 4.5 metres tall and has a large, attractive looking white flower.

But it also has a toxic sap that can cause third-degree burns when exposed to sunlight and even blindness if it gets in the eyes.

"It's a nasty one," Ferguson said. 

Foreign invaders

There are already many invasive plant species threatening Alberta's native natural habitats. 

Ferguson said most invasive species have been in Canada since the 1800s and were brought to the country by settlers either by accident or sometime on purpose.

Spotted knapweed is a prohibited noxious weed that aggressively colonizes pastureland. (Alberta Invasive Species Council )

"A lot of the nice looking invasive species were often brought over because someone thought 'Wouldn't that look great in my garden?'" Ferguson said. 

"Little did they know once it escaped it could be a big problem for natural spaces."

Those species include:

  • Canada thistle.
  • Common tansy.
  • Spotted knapweed.
  • Leafy spurge.
  • Japanese knotweed.

Ferguson said these plants spread aggressively through grasslands and rangelands, ruining forage crops and taking over habitats supporting Alberta's native insects and pollinators.

Kristyn Ferguson, conservation scientist and a program director with the Nature Conservancy of Canada, said common tansy is "a real problem" in Alberta. (Wikipedia)

Most invasive plants are harmless to humans, and these plants can end up in Albertans' gardens. Ferguson said a shovel or chemical weed remover is often all you need to remove the infestation.

But unlike giant hogweed, leafy spurge is already in Alberta and also has a toxic sap which can cause skin irritation or blistering. 

To be on the safe side, Ferguson recommends wearing gloves when dealing with any invasive species.

Canada thistle is a commonly seen invasive species and is easily identifiable by its purple flower and spiky barbs. (Scott Neufeld/CBC)

The Alberta Invasive Species Council has resources available online for Albertans to help identify invasive species. 

There's even a smartphone app called iNaturalist that can connect you with fellow naturalists to help keep invasive species under control.

"You can become an expert and do your part in the battle by [identifying] them, reporting them, and then helping groups get mobilized to take care of them," Ferguson said.