A man has described the horrifying moment he brushed against a weed which burned him so badly he was left hospitalised.
Dean Simmons was out fishing when he walked past a crop of giant hogweed, which touched his bare legs.
A day later, he was on morphine because the burns had left him in "pure agony".
The gardener came out in huge blisters after he brushed against the giant plant, which is also known as Cow Parsnip and is found along most rivers and canals.
He's now been left with skin burns that doctors say could take months to heal.
Giant hogweed sap contains toxic chemicals which are known as furanocoumarins.
According to Royal Horticultural Society, when these chemicals come into contact with skin and are exposed to sunlight, a reaction occurs called phytophotodermatitis.
This usually results in reddening of the skin which is often followed by severe blistering and burns.
Additionally, if the sap gets into a person's eyes it can cause temporary - or even permanent - blindness.
Injuries sustained from giant hogweed can also last for several months, with some areas of skin remaining sensitive to light for years.
Simmons, who is a gardener, was aware of the plant but says that he was "still caught out" by it. He's shared his story in the hope that people become more aware of the dangers of the plant.
After the ordeal, he wrote on his Facebook page: "The burns and pain are going to get much worse. Anyone who lives in Taunton and uses the canal, look out for giant hogweed and keep yourself and the kids clear of it.
"I'm in pure agony and I can't walk. I would hate to see a child in my position. The pain is unreal."