Note : Please don’t send me photos or ask me to identify trees, plants, berries or mushrooms.
This time I want to look at hogweed and giant hogweed.
Nicola and I eat a lot of hogweed (Heracleum sphondylium) at this time of year, the smell of it cooking is just wonderful. I like it with eggs, in an omelette or a quiche topped with a little blue cheese. We also have it griddled, a bit like asparagus, with olives and some chilli flakes, which is delicious.
But you need to make sure that what you’re picking is hogweed and not giant hogweed. Giant hogweed (Heracleum mantegazzianum) isn’t a native plant, it was introduced into the British Isles in the 1800s and has rapidly spread. It tends to be found on river banks and alongside canals; the photo below was taken alongside the Frome in May 2009 and gives an idea of how tall it can get, although it can grow to 5m.
The sap of giant hogweed contains photosensitising furanocoumarins which can cause phytophotodermatitis, or in short nasty burns to your skin when combined with sunlight, and if it gets in your eyes can result in blindness.
We haven’t found any giant hogweed where we’re based on the North Downs, but one of our regulars, Max, sent us some photos recently of some that he spotted in Essex. At this time of year (May) the height of the giant hogweed gives it away, but earlier in spring it isn’t always as obvious. So here are a few pointers to help tell them apart.
The leaves on giant hogweed tend to be very deeply divided, angular and pointed, whilst those of hogweed are more rounded. Hogweed leaves are slightly hairy/downy whilst giant hogweed leaves are hairless.
In the photo below giant hogweed is on the left hand side, hogweed on the right.
Typically common hogweed flowers from May to August; flowers are in an umbell up to 20cm across.
Giant hogweed flowers in June and July and has flowers in an umbell up to 50cm across.
In the photo below giant hogweed is again on the left hand side.
|Typically 4m tall before flowering and can reach 5m||Typically around 2m tall, but very occassionally can reach 3m|
|Can reach 10cm in diameter||Rarely over 5cm in diameter|
|Distinctive purple blotches on a green stem||Purple hue|
|No groove||Groove running down the stem|
|Sharp bristles||Downy, but not sharp|
I hope this helps, but remember, if you aren’t 100% certain, leave well alone – don’t risk suffering a potentially painful injury.