Giant Hogweed (Heracleum mantegazzianum) - dangerous plant

[Astronuc]

TL;DR Summary

Contact with a giant hogweed plant may result in chemical burns from furocoumarins.

Public Safety Announcement.

Earlier today, I read two articles on giant hogweed. In one case, a dog ran into some brush along a trail and apparently came in contact with the plant. His injury was so severe that he was euthanized. In another case, a child came in contact with the plant and received severe chemical burns. Both occurred in the UK.

https://www.manchestereveningnews.co.uk/news/uk-news/dog-dies-after-being-stung-24372779
https://www.manchestereveningnews.c...ws/tot-suffers-horrific-third-degree-24225807

It's been an ongoing problem in the UK
2021 - https://www.manchestereveningnews.c...s/hogweed-burns-hot-weather-injuries-21141790

2015 - https://www.bbc.com/news/uk-england-manchester-33509053

The plant was brought to the UK in the 19th century as an ornamental shrub.

Now, the plant has been found in the US.

Giant Hogweed, recently discovered in Cowlitz County, Washington State.​

https://www.co.cowlitz.wa.us/2908/Giant-Hogweed

Giant Hogweed is identifiable by its towering flower stalk reaching heights of 15 to 20 feet. White flower clusters resemble flat-topped umbrellas; clusters may reach up to 2.5 feet in width. Leaves are deeply cut or lobed with teeth on the edge, reaching up to 5 feet in breadth. The stem and stalks have distinct purple to red spots or blotches and are covered in stiff hairs. A thick circle of white hairs surrounds the base of the leaf stalk.

The most similar plant in our area is native Cow Parsnip, differing mostly in height. Cow Parsnip reaches 5-8 feet tall, has white flower clusters rounded like an umbrella and similar leaves. Giant Hogweed has also been confused with Poison Hemlock, Angelica, Wild Parsnip, and Queen Anne’s Lace.

If one sees or encounters this plant, notify authorities, either Dept. of Agriculture and/or Environmental Conservation. Hazmat equipment must be worn to avoid contact.

https://www.nwcb.wa.gov/images/weeds/giant-hogweed_PW_7-6-16-Clark.pdf

Experts are urging for people to be aware of the plant’s hairy stem where the danger lies, containing organic toxic chemical compounds called furocoumarins.

It is easy for people to brush up against giant hogweed without realising, with the sap's toxins making themselves known in major ways causing burns and scars. In the short-term, people can suffer from blisters and rashes as well as painful inflamed areas.

However, the long-term consequences are more dramatic with people facing potential disfiguration or long-lasting purple blotches on their skin. Those worst affected could even suffer with skin irritation for months or years after the plant made contact with them.

I didn't know this - "Furocoumarins are a class of photoactive compounds found in several plant species and may be responsible for the observed association between consumption of citrus products and the risk of skin cancer."
https://pubs.acs.org/doi/10.1021/acs.jafc.7b01279

https://en.wikipedia.org/wiki/Furanocoumarin (or furocoumarin)

I need to do more research into this.

Edit/Update: https://www.sciencedirect.com/topics/medicine-and-dentistry/furocoumarin

 

[fresh_42]

Wikipedia:

The skin irritation and blisters can cause weeping sores that last for weeks and are associated with persistent pigment changes. Fever, sweating and circulatory shock can also be the result of contact with the plant.

 

[hutchphd]

Holy crap.
Can we just talk about, say, raindrops on roses and whiskers on kittens for a week or so...

 

[Bystander]

Summary: Contact with a giant hogweed plant may result in chemical burns from furocoumarins.

I need to do more research into this.

Parsley, limes, are among "many, many, many" (apologies to fans of Lesard) photochemical irritants. Once exposed to direct sunlight, watch out...