One of the world’s most venomous plants, the Gympie-Gympie stinging tree can cause months of excruciating pain for unsuspecting travellers or bush-walkers
If you are walking through the rainforest and experience an intense, painful stinging sensation, then you have probably brushed against a Stinging Tree or Gympie-Gympie tree. Other symptoms include redness, sweating and increased heart rate.
Whilst the initial, intense pain will persist for several days before easing, it can recur repeatedly over several months whenever the affected area is exposed to hot or cold air, water and rubbing.
The tree has attractive heart-shaped leaves and juicy-looking purple fruits but is covered in hollow silica-tipped hairs which if brushed against, can cause extreme pain lasting several months.
The hairs on the Stinging Tree all point in one direction, so if you can see which way that is and you move your hand with the ‘flow’, rather than against the grain, then you can carefully move the leaves aside to reach the fruits; (which remarkably are edible but somewhat tasteless); although this is not recommended.
The Stinging Tree (Dendrocnide moroides) is found in Australia’s Tropical Rainforests and is one of four species of Dendrocnide in the family Urticaceae in Australia. It is believed to be the most toxic.
Flourishing in areas of disturbed rainforest, the Stinging Tree is commonly found growing alongside walking tracks and in clearings. Often single-stemmed, it grows up to two metres high and its large leaves span up to 30cm x 22cm.
So just how painful is this thing?
This is one of the world’s most venomous plants, capable of killing dogs, horses and humans. If it doesn’t kill you, expect months of excruciating pain. The Australian Geographic describes the pain as...
“like being burnt with hot acid and electrocuted at the same time..”
Marina Hurley's experience
Marina Hurley's dedication to science was sorely tested during the three years she spent in Queensland’s Atherton Tableland studying stinging trees. The entomologist and ecologist’s first encounter with the Gympie-Gympie stinging tree produced a sneezing fit and left her eyes and nose running for hours. Even protective particle masks and welding gloves could not spare her several subsequent stings – one requiring hospitalisation – but that was nothing compared with the severe allergy she developed.
“Being stung is the worst kind of pain you can imagine - like being burnt with hot acid and electrocuted at the same time,” said Marina, who at the time was a postgraduate student at James Cook University investigating the herbivores that eat stinging trees.
“The allergic reaction developed over time, causing extreme itching and huge hives that eventually required steroid treatment. At that point my doctor advised that I should have no further contact with the plant and I didn’t object.”
Les Moore's Experience
So swollen was Les Moore after being stung across the face several years ago that he said he resembled Mr Potato Head.
“I think I went into anaphylactic shock and it took days for my sight to recover,”
said Les, a scientific officer with the CSIRO Division of Wildlife and Ecology in Queensland, who was near Bartle Frere (North Peak) studying cassowaries when disaster struck.
“Within minutes the initial stinging and burning intensified and the pain in my eyes was like someone had poured acid on them. My mouth and tongue swelled up so much that I had trouble breathing. It was debilitating and I had to blunder my way out of the bush.”
How to treat a sting
If you are stung by a Stinging Tree the best way to remove the hairs is by waxing, or applying and then removing band-aids repeatedly to the affected area.
The most important thing is that you do not rub the area, as this can break off the hairs and make them very difficult to remove. Applying diluted hydrochloric acid (1:10 by volume) to neutralise the hair's peptide coating, followed by waxing strips to remove the stinging hairs should provide relief within around one and a half hours.
While you may be as "miserable as hell" the treatment with the acid/hair strip approach should reduce the severity and duration of the pain.
Could the plant be used for nefarious purposes?
It was perhaps the rapid and savage reaction to the tree's toxins that inspired the British Army’s interest in the more sinister applications of the Gympie-Gympie stinging tree in 1968.
That year, the Chemical Defence Establishment at Porton Down (a top-secret laboratory that developed chemical weapons) contracted Alan Seawright, then a Professor of Pathology at the University of Queensland, to dispatch stinging-tree specimens.
“Chemical warfare is their work, so I could only assume that they were investigating its potential as a biological weapon,”
Alan, now an honorary research consultant to the University of Queensland’s National Research Centre in Environmental Toxicology, added...
“I never heard anything more, so I guess we’ll never know.”