Giant hogweed (Heracleum mantegazzianum) is an invasive weed which is really dangerous. The early warm weather has provided perfect conditions for it to thrive, and specimens have been seen in Glocestershire, mainly along the banks of waterways.
It looks a bit like cow parsley, but is much bigger – it can grow up to several meters tall, with flowers 80 cm across and red-spotted, hairy stems 3-8 cm thick.
The sap of this plant can get on to your skin if you just brush the leaves or stem. It prevents the skin from protecting itself from sunlight and this can quickly cause very serious burns and blisters.
If you see any stay well away and report to Environmental Health because it requires specialist treatment.