An excruciating pain compared to “being burned with acid” and which lasts a very long time: this is the typical reaction to the sting of Dendrocnide moroides, considered as the most painful plant in the world and called the “suicide plant”. Belonging to the Urticacee family and with the size of a small tree, the Dendrocnide moroides it has leaves covered with tiny needles which break in the skin of anyone who touches it, releasing stinging toxins, called gympietides, responsible for the severe pain reported by those who have come into contact with the plant. The problem is amplified due to the persistence of both the toxins and the needles, which can remain under the skin for a very long time before dissolving. There Dendrocnide moroides it is so stinging that even just fragments of needles suspended in the dust around the plant would be able to trigger very strong reactions with symptoms similar to those of allergies: redness, swelling and redness of the affected area.
The defensive strategy of nettles
There Dendrocnide moroides it is present only on Malaysian and Australian territory, where it is called Gympie-Gympie in the language of the local indigenous people Kabi Kabi. Like all Urticacee, it has evolved an effective deterrent against herbivores: on the surface of the leaves there are thousands of trichomesor specialized elongated cells needle-shaped which contain stinging substances at their base. This needle is 1 to 3 mm long depending on the species, the external walls are calcified and the tip is coated with silicon oxide. The pointed shape and rigid structure cause the trichomes of nettles they break easily on contactgetting stuck under the skin of herbivores who try to eat them or anyone who touches them even by mistake. The composition of the toxin varies from species to species but usually includes histamines, neurotransmitters that cause pain and inflammation in the affected area. In the nettle commonly present in our meadows, Urtica dioica, the stinging reaction disappears after a few minutes or at most within a day. But for Gympie-Gympie it is different.
Gympie-Gympie toxin
There Dendrocnide moroides it is distinguished from other nettles by its potency of its toxin and above all for the duration of the reaction. For a long time it was not clear what specific substance could cause such excruciating pain: only recently, a study from the University of Queensland identified a new class of neurotoxinsnamed gympietids. Their chemical composition is highly similar to that of poison neurotoxic of conidia molluscs; it is also a very stable composition, and therefore long-lasting once it enters the body. Gympie-Gympie needles are also much more resistant than normal and can remain under the skin for up to a year, continuing to release the toxin every time they are moved.
The effects of the sting on humans
The testimonies of those who have unfortunately touched the leaves of the Dendrocnide moroides they all tell of a very strong pain in the acute phase of the reactionwhich can last several days and which is characterized not only by intense pain, but also by symptoms similar to an allergic reaction: redness, sneezing, swollen tongue, blocked airways. The pain is lumped together with that of a strong acid on the skin and makes you unable to sleep or concentrate on any activity. Once the acute phase has passed, the strong pain returns every time the affected area is touched, disappearing completely after a long time – the duration of this phase depends on the circumstances but usually ranges from two weeks up to several months. Ernie Rider, an environmental conservationist who was hit in the chest by this plant in 1963, stated that the pain returned to the affected area every time he took a cold shower, up to two years after the event.
It seems that even just being close to the plant could cause strong reactions, without even touching it: since the needles are fragile to the point of breaking with a gust of wind, needle fragments and traces of toxin could remain in the dust surrounding. But experimental confirmations are lacking. In any case, those who study the Gympie-Gympie wear protection on their skin, eyes and nose not only when handling it, but also when observing it.
As well as cases of horses driven mad by pain to the point of having to be killed, the botanist HJ Winkler also reports a certified case of a man whose death is attributable to the sting of Gympie-Gympie, which occurred around 1920. Legend also has it that an Australian officer committed suicide out of pain after using its leaves as toilet paper, but this is most likely a rumor that increases the already fearsome reputation of this plant.
