People across Stirlingshire are being urged to treat giant hogweed with caution after many people suffered burns from the toxic plant around the UK in the past weeks.

According to experts, the plant poses a significant danger to public health. Giant hogweed sap is extremely toxic to the skin when it is exposed to sunlight after contact and local volunteers are fighting the battle to eradicate the notorious plant, which grows along wasteland, streams, railways and the banks of rivers like the Allan and the Forth.

The local volunteers are backed by Scottish Natural Heritage, the Scottish Wildlife Trust and the Forth Fisheries Trust. One volunteer, Bill Jack, told the News: “Our group is anxious that public awareness of the dangers of giant hogweed is heightened and that people are at least able to recognise this plant.

“The Allan Water catchment and parts of the Forth in and near Stirling are well known black spots.

“There is a very real risk that giant hogweed will spread out of control in our area unless the powers that be - local authorities, Network Rail and landowners - start taking this problem seriously and devote more time and resources to giant hogweed control.” Mature flowering giant hogweed (heracleum mantegazzianum), which looks much like its close relative – the harmless Cow Parsley - can grow 4-5 meters tall and has leaves 1.5 meters in length. The plant, which is not native to the UK, can colonise ground rapidly with tens of thousands of seeds produced in its third to fifth year.

The sap of the plant contains furanocoumairns, a chemical which in contact with the skin and in the presence of ultraviolet light produces extremely painful burns and blisters, which often need hospital treatment. This reaction can recur for many years.

Contact with the eyes may lead to temporary or permanent blindness. The volunteers estimate the group sprayed over 30,000 plants this year between Bridge of Allan and Dunblane and a further 5000 plants remain untreated.

Mid Scotland and Fife MSP Murdo Fraser has recently called on local authorities to take a more proactive approach and do more to tackle the spread of the invasive species and also urged the Scottish Government to launch a widespread public awareness campaign.

He said: “Under the invasive species act it is illegal to grow giant hogweed, but despite this the plant is growing rapidly thanks to its [up to 50,000 seeds] which can disperse and sow themselves with ease.

“Where hogweed is reported it is up to the landowner to destroy it, this approach is clearly failing and I would like to see Perth & Kinross, Fife, Stirling and Clackmannanshire councils take a more proactive approach to eradicating the plant.

“Giant hogweed is spreading fast and clearly, a new joined up approach is required to stunt its growth and local authorities need to lead on this.

“The dangers of touching or brushing up against the plant are far ranging and can cause damage that is noticeable for years, I would like to see the Scottish Government create a fresh public information campaign to increase awareness of the dangers of this plant.” A Stirling Council spokesperson said: “Stirling Council’s Fisheries Service has an ongoing programme for controlling giant hogweed on areas where fishing takes place and the immediate vicinity, during the fishing season. Other than that, controlling the plant is the responsibility of individual land owners.

“We advise the public to be extremely careful around the plant, which can cause serious skin problems. If you are tackling giant hogweed on your own property, please make sure that you are completely covered in protective clothing with no skin showing and take great care not to touch the plant. Cutting with secateurs before the hogweed flowers and then spraying with weedkiller is an effective way of dealing with it.”