This is hogweed (Heracleum sphondylium), first cousin to the giant hogweed (Heracleum mantegazzianum) which the Daily Mail tells us has invaded Virginia, USA, and will blind us all.
“A horror plant that causes third-degree burns and permanent blindness has been spotted in Northern Virginia…” Daily Mail 6th July
Both species contain phytophototoxic chemicals; if you get phytophototoxins on your skin, exposure to sunlight, specifically ultraviolet light, can cause rashes and burns in susceptible people. Sweating and high humidity can make the reaction worse and it is sometimes called strimmer’s rash: the strimmer spreads the chemicals around and the hot sweaty operator gets it on their skin.
Giant hogweed contains much more of these chemicals than our common hogweed and should be handled with great care.
The flowers, called umbels because of their umbrella-like shape, provide pollinators with a platform to work from, and lots of nectar; they are a favorite of beetles, flies, butterflies and photographers. It is rare to find a hogweed flower without an invertebrate visitor busy at just the right height for easy photography.
In autumn and winter the seedheads are an important food source for seed eating birds, and all kinds of insects overwinter in the plant’s tall, hollow stems. Hogweed is generally considered unwelcome in our gardens, and rooted out, but a single plant left through the winter will attract seed eaters and the stems will make a better bug-hotel than any you can buy in the garden centre.
Header picture by DKG