Stinging trees grow in rainforests throughout Queensland and northern NSW. The most commonly known (and most painful) species is Dendrocnide moroides (Family Urticaceae), first named “gympie bush” by gold miners near the town of Gympie in the 1860s.
My first sting was from a different species Dendrocnide photinophylla (the shiny-leaf stinging tree). It was like being stung by 30 wasps at once but not as painful as being stung by D. moroides, which I once described as the worst kind of pain you can imagine – like being burnt with hot acid and electrocuted at the same time.
I agreed to study stinging trees even after being badly stung. The puzzle was – what was eating the stinging tree? Stinging trees often have huge holes but no-one knew what was eating them. What could possibly eat the leaves that were so painful to touch?
Stinging trees grow in light-filled gaps in the rainforest understorey and come in many different shapes, sizes and species (seven in Australia).I studied two species for my PhD, Dendrocnide moroides and Dendrocnide cordifolia which is often mistaken for Dendrocnide moroides. Both species are shrubs that grow to three metres with heart-shaped, serrated-edged, dark-green leaves that can grow from the size of a thumbnail to over 50 cm wide.
The sting is caused by stinging hairs that contain toxin and densely cover the leaves, stems and fruit. The thick covering of the hairs makes the leaves look as though they are covered with soft, downy, fur and may give the impression they are inviting to touch.
The fruit of D. moroides is similar to a bright red-dark purple raspberry with long stems, while the fruit of D. cordifolia is always green with short stems that give the fruit a clumped appearance.
