Note : Please don’t send me photos or ask me to identify trees, plants, berries or mushrooms.
This time I want to look at common hogweed and giant hogweed.
Nicola and I eat a lot of common 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 common 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 (but not always); 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 we do find it from time to time as we’re out and about. 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; they are hairless (glabrous).
The leaves of common hogweed are more rounded;they are slightly hairy/downy (pubescent).
Giant hogweed flowers in June and July and has flowers in an umbell up to 50cm across.
Typically common hogweed flowers from May to August; flowers are in an umbell up to 20cm across.
Giant hogweed has a green stem with distinctive purple blotches.
Hogweed has a green stem, sometimes with a purple hue.
|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|
|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.