Where I grew up, nearly half a century ago, I recall that there was a Giant Hogweed plant. I don't recall seeing one since, so when we returned to the valley I returned to the spot to see if it was still there.
Indeed it was, large as life and twice as scary, with a few partners along the field edge.
The plants are about 8' to 12' high, and the leaves are up to 3' across. The stems, which children apparently always want to use as blowpipes, are 3-4" in diameter. I don't recall ever being tempted, nor did I suffer from the consequent blistering burns.
Genesis wrote probably the only song about the difficulties of eradicating alien plant species :
The Return of the Giant Hogweed......
Waste no time!
They are approaching.
Hurry now, we must protect ourselves and find some shelter
Strike by night!
They are defenceless.
They all need the sun to photosensitize their venom.
They don't write songs like that any more.
Considering our Health and Safety culture, and their position near a public road, I'm surprised that the plants have survived.