The Giant Stinging Tree is just that! It is a native tree that grows to 25 metres high and has huge round leaves covered in tiny, poisonous white hairs. The slightest touch of a Stinging Tree leaf on bare skin produces pain that makes stinging nettles seem positively painless. If the leaf touches the skin a little harder, it will produce chemical burns that result in severe pain, severe blistering and the eventual loss of several layers of skin. Basically, its effects are like a severe sunburn. We are not sure what would happen if the leaf touches your eyes but assume it would cause blindness.
The leaves are not the only poisonous part of the tree. The sap in the branches, trunk and roots also produces significant irritation although, from personal experience, nothing on the scale of the leaves. The roots can actually be quite tricky. They spread along the surface and often extend more than a dozen metres from the edge of the tree canopy thus making it very easy to mistakenly cut into one without realising what it is. If a root is long and straight, grey-brown in colour, slightly scungy and anywhere near a stinging tree, beware.