Wednesday, May 13, 2015

Dangerous Fruits

Giant Stinging Tree, Dendrocnide excelsa
This wonderful tree pulls more than its own weight as a member of a rainforest community.

It is a fast-growing pioneer tree, quickly filling spaces in rainforests caused by falling trees or human interference.
It grows to be one of the most magnificent tall trees in the forest, becoming part of its upper canopy.

The leaves of young trees tend to be held horizontally, and are a particularly pretty part of the rainforest scene.

Their translucent light green colour makes the overhead leaves stand out against the darker leaves of the higher canopy.

At the end of the tree’s life-span its soft timber breaks down rapidly, completing the cycle of growth, death and decay that provides habitat for so many species.

This tree had fell across a path at the Bunya Mountains, and has been cut by the National Park rangers to reveal the wonderful fluting of the trunk. Note the tiny stinging tree seedling in its folds. Like seedlings of many other species around it, it is entering the race to fill the canopy gap left by the old, dead tree. What are its chances?

The luscious fruits of stinging trees are eaten by birds and bats. In theory, people can also eat them, but, as they are likely to have stinging hairs amongst the fruits, the outcome could be deadly and is definitely not worth the risk!

The leaves support leaf-eating insects, which sometimes make lacy skeletons of them. Insects are part of the food chain, becoming food for birds, and other animals. The skeletonised leaves are yet another bit of evidence that the stinging tree is playing its part in a healthy local ecology.

How Bad is the Sting?

Because it loves to fill spaces, giant stinging tree often pops up beside National park trails or roads, and visitors learn to be wary of its giant leaves. I find their sting about equal to that of the ordinary nettle Urtica incisa and not very dangerous. However,  different people react differently, so it is best always to be wary of any nettle, whatever the plant’s size.
It would be possible to confuse this plant with a much more dangerous plant, the Gympie stinger, Dendrocnide moroides. Gympie stinger is not native to our district, but grows a little to the north of it. It  is a shrub or small tree with leaves very like those of the giant stinging tree, and its sting is very strong.
Science (and my own experience) tells us that the old wives’ tale of rubbing a nettle sting of any kind with cunjevoi sap to reduce the sting is completely useless. Hair-removal wax strips are the recommended first aid. Some people claim they get at least a partial cure by applying the sticky section of band-aids or elastoplast, the stickier the better, and ripping it off to pull out the little stinging hairs.

A Valuable Plant.
Aborigines made nets and lines from the fibres of the bark of the roots, but modern people have found no used for the soft timber, and of course none of us like to get stung! As a result giant stinging trees have been somewhat underappreciated.
So I am delighted when I find it for sale in certain specialised nurseries. It sells to people for revegetation projects where its potential to make a very high contribution to their local ecology is appreciated.

For notes on the other members of the Urticaceae family, use the white search box at top left

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