This plant makes you feel agony

Touching the Gympie-Gympie tree feels like being burnt by hot acid and electrocuted at the same time. This unassuming Australian shrub is covered in millions of microscopic, hollow silica hairs. When you brush against them, they act like hypodermic needles, injecting a stable neurotoxin that the human body cannot easily break down.

The pain doesn't peak and then fade. It can intensify over 20 or 30 minutes, swelling the lymph nodes until they feel like they are being crushed. Because the tiny glass-like hairs remain lodged in the skin, the pain can flare up every time you take a cold shower or rub the area, even years after the initial contact.

There are historical accounts of horses becoming so distressed by the pain that they had to be shot and forest workers who had to be strapped to hospital beds for weeks. The toxin is so resilient that even dried leaves kept in a lab for a hundred years can still deliver a full-strength sting.

Standard first aid is useless. The only way to treat it is to apply diluted hydrochloric acid to the skin and then use hair-removal wax strips to rip out the silica needles. If hairs remain lodged in the skin, the pain can flare up for many months.

Strangely, while it can drive a human to madness, some species of marsupials and beetles eat the leaves for breakfast. They have evolved a specialized digestive system that ignores the needles entirely.