Where Giant Hogweed has been spotted and why it's dangerous
Giant Hogweed can cause severe burns and blisters - there have been numerous reports of it across Gloucestershire
There's a call for people across Gloucestershire NOT to risk touching a potentially harmful plant called Giant Hogweed.
It follows several reports this summer about young people in the United Kingdom who've ended up with blisters and severe burns after coming into contact with it.
Sightings of Giant Hogweed have been reported in various spots along the River Frome in Stroud, in the Cotswolds and in Leckhampton, south Cheltenham.
Speaking to Free Radio, plant expert and Chief Horticulturalist at the Royal Horticultural Society, Guy Barter, explained what makes the plant so toxic to humans:
"Giant Hogweed have pigments in the sap and these pigments have the unfortunate property of capturing sunlight and reemitting it at a different wavelength - which is damaging and can cause severe burns.
"If you get the sap of these plants on your skin, in bright sunlight, very nasty burns can result.
"If the sap comes into contact with human skin in dull weather, the risks are very much reduced; but the sap can remain in the skin for quite some time and it can still result in burns days after."
What does it look like?
Giant Hogweed is a tall, cow parsley-like plant with thick bristly stems that are often purple-blotched, and it can reach a height of 3.5m (11.5ft) or more.
The flowers are white and held in umbels (flat-topped clusters, like those of carrots or cow parsley), with all the flowers in the umbel facing upwards. The flower heads can be as large as 60cm (2ft) across.
Chief Horticulturalist Guy Barter, says the plant won't cause you any harm if you're simply walking past it - but he's advising us to avoid touching it at all cost:
"Giant Hogweed is pretty recognisable - it's an enormous statuesque plant like a cow parsley on steroids, with the most spectacular architectural foliage.
"It is harmless unless you get sap on your skin.
"Children who perhaps might make a den in a big den stand of the exotic Giant Hogweed plant, they will be at risk of severe burns. But walking by it won't cause you any harm.
"So the golden rule is - do not let Giant Hogweed sap get on your skin. Wear suitable clothing if you're clearing it, and children should be warn not to play in it."
What to do if you see a Giant Hogweed
An interactive map has been created which shows reported sightings of Giant Hogweed in the UK, after the Plant Tracker app project - set up jointly by the Environment Agency, the Scottish Natural Heritage, Natural Resources Wales and the Scottish Environment Protection Agency, designed to tackle the problem of invasive, non-native species - come to an end.
Anyone can report a sighting, and the details will be passed to the Biological Records Centre’s iRecord system so an expert can verify the sighting before it is added to the map.
Plant expert Guy Barter says you should also report any sightings of the invasive plant to the landowner, and to the GB Non-Native Species Secretariat - the body responsible for coordinating the approach to invasive non-native species in Great Britain.
"Giant Hogweed love damp places. It tends to spread along rivers, so if you see a stand of this plant stay well clear of it and report it", says Mr Barter.
"If you're going to attempt to clear it yourself, do it on a dull day, wear protective clothing and cut it carefully with as little spreading as possible.
"I'd advise people also to not introduce it into their garden - that would be an unwise move!"
If you've been unlucky enough to come into skin contact with Giant Hogweed, the medical advice is to wash the skin with cold water and soap, and avoid sunlight for up to 48 hours as burns and blisters could still develop days after contact.
"In the case of severe burns, medical attention should be sought urgently", says Mr Barter.
"Dyes remain active in the skin so even if you wash your skin and remove the dye it can still be present and sufficient to cause injury".