Six Things You Should Know About Eucalypts

This National Eucalypt Day we are celebrating all the amazing things about our beautiful eucs! So here are some little-known facts about one of Australia’s most iconic plant species.

The tallest flowering plant in the world is a Eucalypt.

Given the opportunity, mountain ash (Eucalyptus regnans) will often grow to heights of around 80 metres. However, the tallest mountain ash, know as ‘Centurion’, stands just over 99 metres tall in Tasmania.

Mountain ash is the tallest flowering plant in the world. Photo by Haworthia Ihlathi [CC BY-SA 4.0] via Wikimedia Commons.

Eucalyptus trees can sequester gold.

In 2003, geoscientists discovered a stand of eucalyptus trees that had tiny portions of gold (about one-fifth of the diameter of a human hair) present in their leaves. The eucalypts were able to absorb the gold from the soil around their roots because they were growing directly above a gold deposit.

Eucalypts give the Blue Mountains their name.

The vegetation in the Blue Mountains is dominated by eucalypts, which release volatile oils called terpenoids into the air. These tiny droplets of oil scatter light in a way that causes the mountains to appear blue. You can see the oil glands in a eucalyptus leaf by holding it up to the sun and looking for white and yellowish spots.

The Blue Mountains owe their name – and colour! – to the eucalypts that dominate the landscape. Photo by 0x010C [CC BY-SA 4.0] from Wikimedia Commons.

Eucalypt, eucalyptus and gum tree are not interchangeable labels.

The word ‘eucalyptus’ refers to a single genus of trees. The word ‘eucalypt’ refers to a group of species that belong to multiple genera, including Eucalyptus, Corymbia and Angophora. The term ‘gum tree’ refers to some species of eucalypts that exude a sticky, tannin-like substance called kino, more commonly known as gum. This means that a gum tree is not always a Eucalyptus tree, that a Eucalyptus tree is not always a gum tree, and that a eucalypt can be a gum tree, a Eucalyptus tree, or both. Confused yet?

Eucalypt leaves don’t make koalas drunk.

The notion that koalas are constantly in a state of drunkenness due to the toxicity of eucalypt leaves is a common misconception. In reality, eucalypt leaves contain so little energy that koalas must eat an enormous amount of them (up to one kilogram a day). Furthermore, koalas must sleep for up to 22 hours a day in order to conserve the little energy that they do obtain from their diet. For all the fun facts there are to learn about eucalypts, one of the best things about them is their iconic symbolism throughout Australian culture – let’s celebrate how lucky we are to have such unique and beautiful trees growing amongst us. Happy National Eucalypt Day!

Despite popular opinion, eucalyptus leaves do not make koalas ‘drunk’. Photo by Rennett Stowe [CC BY 2.0] from Wikimedia Commons.

Banner image by Perpitus [CC BY-SA 2.5] from Wikimedia Commons.