Warning as toxic plant that can cause blindness and burns spreads in UK

Giant hogweed is often confused for less dangerous plants including common hogweed or cow parsley

Described as Britain’s ‘most dangerous plant’ the toxic weed can grow up to 20 feet tall and can spread out to cover around two metres of ground.

Giant hogweed, also known by its Latin name Heracleum mantegazzianum, originated in Southern Russia and Georgia, and was first introduced in Britain in the 19th century from the Caucasus Mountains.

The earliest documented reference to the plant has been traced back to the Royal Botanic Gardens Kew Seed List of 1817, where seeds of the plant were listed.

The plant has a thick green stem with patches of purple and white hairs on it, and can grow up to 20ft high, while the thick leaves can grow to five feet in width. The flowers usually appear in June and July, and are small and white and appear in clusters on “umbrella-like heads” that face upwards.

It can be easy to confuse giant hogweed with its lookalike cow parsley. You can tell the difference between the two by the height as cow parsely can only grow about three to four feet tall. Cow parsely also has smaller florest and broader leaves which are more rounded compared to the jagged leaves of giant hogweed.

The sap is what makes giant hogweed so dangerous as it contains a chemical called furocoumarin, which makes the skin sensitive to the sun and can cause painful blistering.

In the short-term, touching the plant can result in blisters, rashes and inflamed or irritated skin, but the plant can cause longer lasting effects.

Those worst affected could suffer with potential disfiguration, long-lasting purple blotches and skin irritation that can last for months or even years after coming into contact with the plant.

Giant hogweed can also cause damage to more than just the skin. If the sap gets into your eyes it can cause temporary or permanent damage, and breathing in sap particles can result in respiratory problems.

What should I do if giant hogweed touches my skin?

If you accidentally get giant hogweed sap on your skin, Healthline says that you should wash the area with mild soap and cool water as soon as possible and keep the skin covered when outside to protect it from sunlight.

If a rash or blister begins to form, you should seek medical attention. The treatment required will depend on how severe your reaction is.

The plant is found across the UK, but more specifically, it will be growing by river banks where the seeds are transported via the water.

What should I do if I find giant hogweed?

There is no statutory obligation for landowners to get rid of giant hogweed, but local authorities can help to arrange the disposal of it to remove infestations in public areas.

You can check who your local authority is via the government website.