Gympie-gympie

Gympie-gympie (Dendrocnide moroides) is a stinging tree of the rainforests of northeastern Australia. Its heart-shaped leaves are covered with fine hairs that inject a toxin, causing pain that can last for weeks or months.

🧬 Field Guide Specimen: Open Gympie-Gympie in the CRV Science Field Guide to log the specimen, see its place among the Diaphoretickes lineages in the Cladogram Explorer, and test your recall in the Red List conservation game.

The hairs (trichomes) are hollow silicon-tipped needles that break off in skin and deliver a mixture of peptides. In 2020 researchers identified the main pain-causing compounds as small, disulfide-rich peptides, which they called gympietides, that act on sodium channels in nerve cells, resembling peptides in spider and cone snail venoms.

The toxin keeps pain signals firing, and the sensation can return when the skin gets wet or is exposed to cold for months afterward. The plant evolved the sting to deter large browsers, though some insects and animals eat the leaves with impunity.

Workers wear respirators, gloves and body protection, since even dried leaves and the dust can sting. Tape is used to pull out hairs rather than rubbing.