Nature Conservancy of Canada is urging people across the country to watch out for a towering, three-metre-tall green plant with large white flowers. Biologist Dan Kraus says giant hogweed is cutting a wider swath in B-C, Ontario, Quebec and the Atlantic provinces. Some may consider the plant pretty, but experts say it can be nasty, causing third-degree burns or even blindness. Horticulturalist Todd Boland says simply touching the plant isn’t dangerous, but the sap can cause huge water blisters — almost like boils — that erupt on the skin.