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The "suicidal" horror plant was kept at home by him

author:Global Science
The "suicidal" horror plant was kept at home by him

Photo by Edward Gilding

It's not a good habit to want to touch something furry when you see it.

In Australia's rainforests, there is a shrub called "Dendrocnide moroides".

At first glance, it is nothing special, with broad leaves and mulberry-like fruits. If there is anything striking about this plant, it is that it is full of hair, as if it feels good in the hand, and it is easy to make people want to caress.

However, if it is really touched, human beings are likely to regret it because of the unbearable pain. Marina Hurley, an Australian ecologist who recalled being "bitten" by a goldbark tree, said it was as painful as giving birth to, or even more so, than giving birth, as if being burned and soured at the same time.

Moreover, the pain caused by this plant is usually long-lasting, not the kind that will pass after a while. Scratching your liver can last for days or weeks, or it can be months. Because this pain is so difficult to get rid of, sometimes even worse than death, the goldbark tree is affectionately known as the "suicide tree".

Even more desperate, even if you don't take the initiative to touch the goldbark tree, you may not be immune to poisonous hands, especially for people and their horses who need to walk through the forest. Since the 19th century, there have been records of the death of horses by goldbark trees. It has also been documented that horses "stung" by this plant can become extremely violent, and humans are unable to parry, so they can only shoot the horse.

Recently, this plant, which can be exchanged for long-term torture at the touch of a touch, was kept at home by a resident of Oxfordshire, England.

It hurts so much, who did it?

The goldbark tree got its name because in the language of the Gubbi Gubbi people of Queensland, Australia, the thorny tree is called "gimpi-gimpi", pronounced like "golden bark". But as mentioned at the beginning, the branches and leaves of the goldbark tree are covered with "fluff", which looks obviously soft and amiable, where does it look like it has thorns?

Warm exteriors can deceive strangers, but experienced locals or scientists with research know the power of those "villi" — they are actually trichomes, which look like fine strands of hair but work as sharp as a hypodermic needle.

The "suicidal" horror plant was kept at home by him

The sharp trichomes of the goldbark tree (Image: University of Queensland)

Specifically, the reason why trichomes can become sharps is largely because silica gives it enough rigidity. There is a small ball at the tip of the trichomes, and as long as it touches the skin, the ball will peel off, revealing a sharp needle that can pierce the skin and take advantage of the opportunity to release venom. This is where the pain begins.

These stingers are so small that when they penetrate a person's body and break, the opening in the victim's skin may directly "close" as if they had just not been stabbed. Sometimes, it is difficult for injured people who are unfortunately stung by goldbark trees to remove the poisonous stingers.

Unfortunately, the toxic substances carried by the goldbark tree are very stable and not easy to decompose. Dr. Marina Hurley, who was once pricked by the plant, says that even a dry leaf, left in the specimen room for 100 years, can still cause pain because the toxin has not yet failed.

The "suicidal" horror plant was kept at home by him

Looks furry (Image: Plant Secrets)

It was Dr. Hurley's nightmare, but not just herself. For years, scientists have searched for what exactly is the unpleasant substance of the goldbark tree. In early studies, molecules such as histamine, acetylcholine, and formic acid were suspected. However, after the human body is injected with these substances, the intensity of pain and the duration of pain cannot be compared with the effect of touching the goldbark tree.

There should be other molecules responsible for the intense and lasting pain. In the 70s and 80s of the last century, researchers found a peptide composed of 8 amino acids in the venom of the goldbark tree, which caused pain when injected subcutaneously. Because the Latin name of the goldbark tree is Dendrocnide moroides, the toxin is named moroidin.

Of the coarse extract of leaves of goldbark trees, moroidin accounts for only about 0.002%. Scientists once believed that this was the root of all evil they were looking for. But later experiments showed that local injection of 10 micrograms of this substance caused a weak pain response; If you use the leaf extract directly, 1 microgram is enough to bring severe pain. Well, Moroidin is probably not the main culprit yet.

The "suicidal" horror plant was kept at home by him

The thorn hairs of the Australian giant thorn tree D. excelsa (Image source: original paper)

In 2020, a team led by researchers at the University of Queensland identified new molecular suspects, but first in another thorny plant, Dendrocnide excelsa. It is a giant thorn tree that can sometimes grow to about 40 meters tall, but is related to the low goldbark tree, also from the nettle family, the genus of hemp trees, and also has sharp trichomes that release distressing toxins.

Scientists isolated an unknown class of pain molecules from the trichomes of giant thorn trees, with molecular masses much larger than the moroidin toxin discovered many years ago. After finding the genes encoding these molecules, the researchers noticed that similar genes were working in the goldbark tree, and that these genes in both species were responsible for encoding a 36-amino acid peptide — a newly discovered family of toxins called gympietides.

The "suicidal" horror plant was kept at home by him

Some members of the chrysopeptide family, ExTxA-C from the giant thorn tree D. excelsa, and MoTxA from the goldbark tree (Image source: original paper)

The researchers synthesized the toxin in the lab, diluted it with saline and administered it locally to mice. As a result, the mouse produced a pain response that reproduced the real scene when stung by a thorn tree: for the injected left hind paw, the mouse would immediately lick and bite, shake or lift the foot. In addition, although they all belong to the chrysopeptide family, the synthetic chrysotoxin has a more obvious effect than the synthesized giant spiny tree toxin. It just so happens that in folk records, being stung by a goldbark tree is also more serious than being stung by that tall thorn tree (the goldbark tree is probably the most painful of all plants in Australia).

Not only that, scientists have also found that chrysopeptide is a class of knotting peptides, and the inhibitor cystine node (ICK) is conducive to ensuring the stability of 3D structures. They remembered that the reason why many spider toxins are exceptionally stable is closely related to ICK. Researchers believe that chrysopeptide is an ultrastable toxin, which means that after it enters the body, it may remain intact for a long time. This may also explain the enduring pain when people encounter goldbark trees.

Some people want to get together

Although the venom composition of this plant is complex, and many of its molecules are associated with pain, in the eyes of scientists, chrysopeptide is more like the main culprit of creating hell-level pain than moroidin.

Dr. Marina Hurley once received a letter from an Australian veteran. The letter said he was stung by a thorny tree in 1941 while crossing a creek in north Queensland. Because the pain was so bad, he went crazy like "a cut snake" and ended up tied to a hospital bed for three weeks. The veteran also recounted an officer who shot himself because he couldn't bear the pain after using the leaves of a thorny tree as toilet paper.

The story of the suicide of an officer is famous, but there are serious doubts about its authenticity. Normally, the first time a goldbark leaf is touched, humans should immediately understand how painful it is, and it is hard to imagine anyone who would continue to use it for other purposes. Of course, even if the story is false, it does not prevent people from thinking of the goldbark tree as a "suicide tree": usually not fatal, but always tortured.

Botanist Ernie Rider works for Queensland Parks and Wildlife Service. In 1963, the leaves of the goldbark tree pierced Ryder's face, arms, and chest, and he later recalled:

"For two or three days, the pain was so unbearable that I couldn't work or sleep. It felt like having big hands pressed against your chest. The very severe pain lasted for two weeks. For the next two years, every cold shower would recur..."

In Ryder's eyes, there is nothing worse in life, and he probably won't want to touch the goldbark tree a second time. But sometimes, even if people don't come into direct contact with the plant itself, and those needle-like trichomes float in the air, they can still hurt people.

Also in the '60s, a man named W. MacFarlane. V. MacFarlane) researchers wrote in an article that he had inhaled some of the trichomes and possibly some dust of the goldbark tree while studying it. After that, within 10-15 minutes, he started sneezing.

But sneezing is just the beginning. After 3 hours of inhaling those stings, McFarland developed diffuse pain in the nasopharynx. After 26 hours, a sore throat like inflammation of the tonsils occurred. The sinuses also continued to hurt, and in addition to sneezing, a runny nose began. Later, the nasal mucosa is shed along with blood, pus, and some sticky secretions. The discharge of exfoliated tissue lasted for about 10 days.

Later, McFarlane wore gas masks when handling goldbark trees. He said that the eyes seem to be more resistant to the golden bark tree than the nose, but the dry plant dust may cause some mild conjunctivitis.

It's dangerous to touch, it's not safe to breathe around it, and it may not even be healthy to look at it - the goldbark tree is probably such a creature that ordinary people avoid it. But maybe you remember the beginning of the beginning, an Englishman recently started raising goldbark trees.

The "suicidal" horror plant was kept at home by him

Goldbark tree in a cage (Credit: Daniel Emlyn-Jones)

His name is Daniel Emlyn-Jones, he is 49, he received his PhD from the biology department at University College London more than 20 years ago and did postdoctoral research in Australia. He has now returned to live in the UK and is engaged in science education. Daniel had always been interested in botany, but was a little tired of geraniums and thought it was an interesting idea to keep goldbark trees at home. He contacted the local Oxford media, thinking they might want to report on it.

As a result, not only local media wrote stories, but media outlets around the world also took action. Now Daniel, who is troubled by the misinterpretation of the media, said that he did not raise goldbark trees because his life was "boring", but only "bored" with geraniums. Daniel also said that he wanted to attract more people to botany.

In contrast, the dangers of the goldbark tree do not seem to bother him as much as the media. Daniel kept the goldbark tree in a cage with a "DANGER" warning sign and the inscription: If stung, don't rub it with your hands. Daniel says he knows exactly what to do with the plant.

HealthDirect, Australia's officially funded health service, gave the same warning, explaining that if you rub against the bitten area, the hairs of the goldbark tree may sink deeper and it will become more difficult to remove them. If the stinging bristles are visible, the official recommendation is to remove them with tweezers, and if it is aimed at an entire area, the stinging bristles can be glued off with wax or tape.

Of course, the best thing to do is not to encounter this plant, at least for humans and some animals. However, other animals seem to be completely unafraid of the venom of the goldbark tree. The leaves of the goldbark tree are often bitten and bruised, and some beetles in Australia, which can walk between the stinging hairs, seem to have little effort to avoid danger and feed from the leaves. In addition, there is the Thylogale stigmatica, which can even eat all the leaves of a goldbark tree in a day without showing signs of being stung.

The "suicidal" horror plant was kept at home by him

Photo by Mark Gillow via Wikimedia Commons, CC BY 2.0

Maybe one day, scientists will master special techniques that can also make humans no longer stung by goldbark trees. But before that, if you like furry creatures, why not pet cats?

Written by: Chestnut, Revised: Erqi

Original paper:

https://www.science.org/doi/10.1126/sciadv.abb8828

Resources:

https://link.springer.com/article/10.1007/BF02858878

https://theconversation.com/australian-stinging-trees-inject-scorpion-like-venom-the-pain-lasts-for-days-146115

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3153181/

https://distribution.arte.tv/fiche/SECRETS_DE_PLANTES

https://www.jstor.org/stable/4252456

https://www.youtube.com/watch?v=h-sOZ17X8xk

https://www.youtube.com/watch?v=7MvXfJmRbWQ

https://www.oxfordmail.co.uk/news/23089713.oxford-man-grows-worlds-dangerous-plant-home/

https://theconversation.com/the-worst-kind-of-pain-you-can-imagine-what-its-like-to-be-stung-by-a-stinging-tree-103220

https://www.healthdirect.gov.au/stinging-plants