A teenager spent days in hospital after merely brushing past Britain's "most dangerous plant".
Jayden Channon, 14, struggled to walk and needed morphine after he was exposed to the hated giant hogweed while gardening at a neighbour's house.
Unaware of the danger, he cut it down, leaving his arms, legs and neck defenceless against the sun when its sap got on his skin.
The boy's flesh broke out in agonising blisters soon after, and the teenager spent three days in hospital. Jayden, of County Tipperary, Ireland, is now badly scarred.
"He was just doing a bit of tidying up in the garden and he was using the strimmer," the boy's grandmother, Annemarie Channon, said today.
"Obviously he didn't realise the danger, he didn't even know what it was really.
"When he came home that evening, I looked at him and thought 'Jesus, Jayden, you should've worn your long pants and top because you look like you got all scratched'.
"When he got up the following morning the rash had spread rapidly, across his hands, legs and neck.
"The next day the rash had completely turned into these huge blisters."
Jayden showed the doctors photos of what he had been cutting - and he discovered it was giant hogweed, which has been described by experts as Britain's "most dangerous plant" in the past.
Annemarie thinks he had a combination of second and third-degree burns. She continued: "He was in chronic pain, to the extent that they put him on morphine for one of the days at the hospital.
"Because of the blisters he couldn't really walk up and down the stairs and found everything so difficult.
"He had to hold on to my shoulder walking along the hospital corridor to the bathroom, because on the backs of his knees he had blisters.
"I was shocked at the damage it caused - really shocked. I wouldn't think a plant could do such damage."
The danger of the giant hogweed is its sap, which stops the skin protecting itself against the sun's rays, leading to gruesome burns.
And to make matters worse, it causes no immediate pain, so its victims often continue to burn in the sunshine heedless of any problem.
On top of all that, the sap only takes a moment to do its work.
Thankfully, Jayden's wounds did not get infected and he's now on the road to recovery.
But it could be years before his skin is back to normal.
Annemarie said: "Now he'll have to wear a special extremely-strong sun cream and he could have sensitivity to the sun for a long time to come.
"I was speaking to a person who's working to get rid of these plants properly, and he said the worst case he heard of was somebody being sensitive to the sunlight for 15 years."
The giant hogweed is native to the Caucasus, but was introduced to Britain and Ireland as an ornamental plant in the 1800s, and its spread has now got out of control.
Mike Duddy, of the Mersey Basin Rivers Trust, said in 2015 that the giant hogweed was "without a shadow of a doubt, the most dangerous plant in Britain".
If exposed to the plant, you should thoroughly wash the area that made contact and keep it out of sunlight for a few days, the Woodland Trust advises.
