The Hokkaido University campus in Sapporo recently had a brand new visitor in the form of a gigantic and highly toxic plant. It’s called the giant hogweed and its name is no exaggeration as the ones found were identified by their height of around three meters.
The giant hogweed can get even taller, up to around five meters, and has a rather innocuous weed-like appearance that belies the dangers that lurk within it. The plant’s sap contains a phototoxic substance that, when in contact with the skin and exposed to sunlight, causes severe swelling and blistering.
▼ News report on the discovered giant hogweed
Hokkaido University quickly cordoned off the area and cut down the plants, but the unexpected presence of them could suggest that there’s giant hogweed elsewhere in Sapporo or even in other parts of Japan. It’s unclear how the plants got to the campus in the first place but an expert suggested that seeds may have been accidentally carried on someone’s shoes or clothing.
News reports have been calling the giant hogweed “one of the most dangerous plants in the world” and if you google “most dangerous plants in the world” it actually does appear among hemlock and nightshade in the top nine. However, it’s not known to be lethal, with the worst effect being temporary blindness if the sap gets in your eyes and is activated by UV rays.
The other good news is that giant hogweed is only dangerous when the sap is touched. Its phototoxins cannot be spread any other way, such as over the wind, but nevertheless, the effects of touching it are about as unpleasant as it gets.
If you happen to come into contact with it, wash the area as soon as possible, doing so carefully to avoid spreading it to other parts of your skin. Also, handle clothing carefully while cleaning it. If skin irritation does occur it can be alleviated with topical steroids, but for the most part you’ll just have to wait it out for a few days. Affected areas will also be extra sensitive to sunlight possibly for years after exposure, so sunblock or long sleeves may be needed.
You’re better off preventing it from ever happening by keeping your eyes peeled for plants that look like the giant hogweed and reporting them to your local authorities as soon as possible so they can dispose of them safely. There is a good chance it might just be a less hazardous hogweed species, but better safe than blistery.
Source: STV News NNN, Itai News, Gouvernement du Quebéc
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10 Comments
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wallace
It causes very nasty blisters or burns if touched.
Garlic eater
If it was 3 meters tall by the time they did anything about it I wonder how many seasons it has had to spread its seeds. Idiots.
OssanAmerica
Hogweed is a major invasive species issue in many US States as well. Makes poison ivy seem tame.
OssanAmerica
Entering any wild brush requires long sleeves (and long pants). Idiots who go into the forests in shorts in the summer are tick magnets. And poison ivy is not fun at all. I know from undesireable experience.
What the heck sunblock has to do with it is a mystery.
wallace
Sunblock will not stop hogweed burns and blisters. Put the picture in your head and stay away. It's an easy plant to spot because it grows so high, very quickly.
Pet owners need to keep their dogs away from it.
It can cause severe blistering, which may take a long time to heal. In many cases, scarring can occur that never completely goes away. If the sap gets into the dog's eyes, it can cause partial, or complete blindness.
nandakandamanda
For those who did not read the article, the sap on your skin is activated by UV rays from the sun. Yesterday someone sent me horrific photos of what look to be severe burns down people's arms and legs. Like urushi poisoning, but worse.
In Japan they call it "Baikal Hana-udo."
OssanAmerica
That is correct.
However, sunscreen (SPF 50) is designed to prevent Sunburn and blocks UVB rays.
The Hogweed sap reaction is Phytophotodermatitis which is triggered by UVA rays. Against which Sunblocks are not effective. For that reason Sunscreen is not considered a reliable preventative for Hogweed contact and is not recommended.
wallace
The only way to avoid Hogweed burns and blisters on the exposed skin is not to touch or brush against the plant. When in a thick undergrown location best to completely cover up. Some people accidentally touch the plant, much to their regret.
My wife has a small black spot on her nose from touching poison ivy when she was a little girl.
Wesley
On a completely unrelated note (cough), several china people were stopped at US airports when they tried to bring in unidentified seeds, mushrooms, etc.
Texas also reported parcels from china containing thousands of seeds of an unidentified nature.
Bio-warfare is a real thing.
Hokkaido University may want to investigate what sort of students/lecturers/maintenance staff they take in.
factchecker
very convenient for the biology students.