Beware the Stinging Tree

Skyrail Nature Diary: September 2008

The Stinging Tree is definitely one plant to be avoided in the rainforest.

Whilst it has attractive heart-shaped leaves and juicy-looking purple fruits, the Stinging Tree is covered in hollow silica-tipped hairs which if brushed against, can cause extreme pain lasting several months.

The Stinging Tree (Dendrocnide moroides) found in Australia’s Tropical Rainforests, is one of four species of Dendrocnide in the family Urticaceae in Australia. It is believed to be the most toxic.

Flourishing in areas of disturbed rainforest, the Stinging Tree is commonly found growing alongside walking tracks and in clearings. Often single-stemmed, it grows up to two metres high and its large leaves span up to 30cm x 22cm.

All of the plant is covered in the fine, toxic hairs which are difficult to see, but easily felt!

If you are walking through the rainforest and experience an intense, painful stinging sensation, then you have probably brushed against a Stinging Tree. Other symptoms include redness, sweating and increased heart rate.

Whilst the initial, intense pain will persist for several days before easing, it can recur repeatedly over several months whenever the affected area is exposed to hot or cold air, water and rubbing.

Interesting, the toxicity of the silica-tipped hairs is not affected by age or heat. In fact research has proven that a dried leaf over 30 years old is still capable of giving a strong sting when touched, so beware.

The Aborigines people called the Stinging Tree ‘Gympie Gympie’ or ‘devil-like’. They would eat the mulberry-like fruits, after developing a careful harvesting technique.

The hairs on the Stinging Tree all point in one direction, so if you can see which way that is and you move your hand with the ‘flow’, rather than against the grain, then you can carefully move the leaves aside to reach the fruits; although this is not recommended.

If you are stung by a Stinging Tree the best way to remove the hairs is by waxing, or applying and then removing band-aids repeatedly to the affected area.

Some rainforest animals - including the Red-legged Pademelon and Green Ringtail Possum - seem immune to the sting of this plant and enjoy eating its leaves and fruits, but the Stinging Tree is definitely one to be avoided when visiting Australia’s World Heritage protected Tropical Rainforests.