The frightening revelation was made by expert gardener Trevor Jones, who runs the celebrated Alnwick Poison Garden. A specialist in poisonous plants, he told Express.co.uk that the danger of giant hogweed should not be underestimated. He shared a gruesome anecdote about a colleague who had fallen foul of the virulent eight foot plant, which grows in waterways and unkempt areas.
Mr Jones explained: “It’s phototoxic which means if you brush against it and you get the sap onto your skin then you start to form blisters.
“We actually had a gardener that was working in our poison garden without protective gear on and she actually did exactly that – brushed against the plant.
“And the back of her hands started to swell and within three hours she was taken to the hospital.
“She ended up with third-degree burns from this plant.
“Now, one of the issues with this is once the toxin is in your system it stays there for up to seven years.
“So every time she goes out in sunlight the blisters start to re-form.
“So there are some pretty dangerous plants like that that people should be aware of.”
Giant hogweed is not native to the UK but originated in Georgia.
It was introduced to the UK in the 19th century as an ornamental plant.
The severe reaction to the plant is caused by the presence of linear derivates of furanocoumarin in the plant’s leave, seeds, flowers, roots and stems.
These chemicals enter the nucleus of human epithelial cells, form bonds with the DNA and cause cells to die.
Commenting on the danger of the plant, Mike Duddy, River Trust expert, said: “If you don’t know what the plant is, it’s exceedingly dangerous.
“It is, without a shadow of a doubt, the most dangerous plant in Britain.”
The Wildlife and Countryside Act 1981 made it illegal to plant or cause giant hogweed to grow in the wild.
Due to the plant’s phytotoxicity and invasive nature, giant hogweed is often regularly removed.
Giant Hogweed has a stout, bright green stem with dark red spots and hollow red-spotted leaf stalks.
Stems typically grow more than two metres high.
The plant also produces white flowers which are clustered in an umbrella-shaped head.