Giant Hogweed must surely be the best known of our introduced plants. Not only is it extremely large – growing to a height of 5 metres – which makes it very easy to identify, but it is also known and feared for its ability to inflict horrible blisters or burns on anyone unwise enough to touch it. Originally introduced from the Caucusus as a stately garden plant, it is a perennial with ridged, stout, purple blotched stems which carry numerous cream-white flowers (10mm) in large umbels (50cm across) in June and July. The leaves are pinnately divided and long (1m). This plant belongs to the family Apiaceae.
I first recorded this plant growing beside the Shanganagh River in Co Dublin in 1980 and I photographed it in the same place in 2005.
If you are satisfied you have correctly identified this plant, please submit your sighting to the National Biodiversity Data Centre