It's a towering, toxic plant that's sprouting up across the country -- including here in Montreal.

Giant Hogweed, with its large leaves and white blooms, looks innocent enough. But the weed produces a noxious sap that can burn the skin and even cause blindness.

When exposed to sunlight after coming in contact with skin, the sap can trigger an inflammatory reaction. If it gets into the eye, it can burn the cornea.

Security tape in Angrignon Park

The troublesome plant was discovered last week at Angrignon Park in Lasalle, much to the dismay of those who regularly visit the sprawling green space.

"No, I didn't know it was there, it's pretty scary," said Sandra Decarie. "We walk all through this park, we drive through it on our bicycles, so it's pretty scary to know something like that."   

Because of a ban on pesticides, the Southwest borough is hoping a saline solution or a vinegar-based acidic treatment will be enough to get rid of the stubborn plants. The process, however, could take months.

"The roots could have offshoots that could spring up again next year, or even later this year," said Pierre Brochu, Division Chief of Parks and Public Works for the borough.

From coast to coast

Giant Hogweed, which can grow to 5.5 metres (20 feet), has been popping up just about everywhere this summer, from Vancouver Island -- where it's been a problem for years -- to river banks in Toronto and Ottawa. It's also spreading along roadsides in Nova Scotia and wasteland areas of Newfoundland and Labrador.

After spotting several of the plants near his home in Wakefield, Quebec, northwest of Gatineau, Rolf Wesche decided to chop them down -- without realizing how dangerous they were.

"At that time, I was dressed in shorts, slashing away at the hogweed plants with my machete and sprayed sap all over myself," said Wesche. 

People who come across the weed are warned to stay clear of it. If you come in contact with the plant:

  • find shelter immediately; avoid sunlight
  • wash exposed skin thoroughly with soap and water

The skin can redden 24 hours after exposure. An inflammatory reaction usually occurs after three days. If you have a reaction, you are advised to see a doctor.

Anyone who thinks they've spotted giant hogweed should contact their local municipality to advise them of its location.

People can also contact the Ministry of Parks and the Environment at 1-800-561-1616.

With files from CTV.ca News Staff