GIANT Hogweed - a toxic plant that can cause extreme blistering, ulcers and blindness - has been sighted in Wiltshire.

The plant continues to spread across the UK, and this interactive map shows data for the number of cases where the deadly plant has been reported in the county, going back nearly 100 years.

According to the Royal Horticultural Society, Giant Hogweed is a close relative of cow parsley originally from Southern Russia and Georgia and it can reach over 3m (10ft) in height.

It is a potentially invasive plant, and the sap can cause severe skin burns, it is widely distributed in the wild and poses a serious risk to people who are unaware of its potential for harm.

The sap contains a chemical called furocoumarin which makes the skin sensitive to the sun, which can cause bad blistering. The blistering can even recur over the span of months, and even years.

This map shows the data for the number of cases in Wiltshire:

What does Giant Hogweed look like?

The Woodland Trust outlines the appearance of Giant Hogweed so that you can better identify the dangerous plant.

  • Stems: the stems are green with purple blotches and stiff, white hairs. The stems are hollow with ridges and a thick circle of hair at the base of each leaf stalk
  • Leaves: the leaves are huge, and can measure up to 1.5m wide and 3m long, and are often divided into smaller leaflets. The Woodland Trust compares them to rhubarb leaves, with irregular and jagged edges, with the underside of the leaf being described as hairy
  • Flowers: the flowers of the Giant Hogweed appear in June and July, and are small and white and appear in clusters on “umbrella-like heads” that face upwards
  • Seeds: the seeds are dry, flattened and an oval shape, almost 1cm long and tan in colour with brown lines

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 quickly as possible.You should keep the skin covered when you’re outside to protect it from the sunlight.

If a rash or blister begins to form, you should seek medical attention. Your treatment will depend on how severe your reaction is.“Skin irritation that’s caught early might be treated with a steroid cream and nonsteroidal anti-inflammatory drugs, such as ibuprofen, to relieve pain,” Healthline explains.

It adds: “Severe burns could require surgery to graft new skin over the damaged skin.”

Healthline also explains that the Giant Hogweed sap can damage more than just your skin - if the sap gets in your eyes, you can experience either temporary or permanent blindness. Similarly, breathing in sap particles can result in respiratory problems.