Three reasons why Eucalypts are an Australian icon

Eucalypts have had a significant role in shaping our history, culture, landscape and even childhood memories.  

Eucalyptus (a part of the Eucalypt family) are in the top 10 genera represented in living collections across the Botanic Gardens of Sydney.  

In our preserved collection held at the National Herbarium of New South Wales there are approximately 73,664 specimens that date back 120 years.  

Here are three reasons why these towering trees are an Australian icon. Worthy of all the glory not just on National Eucalypt Day, but every day for generations to come:  

There are around 300 Australian native animals that are reliant on tree hollows for shelter, nests or a temporary resting spot along their journey. Mammals, birds, reptiles, insects and frogs seek out hollows and are particularly fond of eucalypts.  

Hollow creation is a slow process, especially in Australia where we rely on fungus to eat away at trees, rather than having a helping hand from a bird like a woodpecker. Since these trees have a long lifespan, it gives fungi ample time to break down the matter to help create homes for wildlife.  

Other than koalas, many species of non-flying mammals such as possums also depend on tree hollows for shelter and survival because they cannot fly away in danger. In fact, most animals choose trees that have hollows over those that don’t.    

Eucalypts have evolved to live in dry environments with long dry spells. This has made them incredibly adaptable to withstand heat since they have insulated seeds that only open in response to fire.  

They even have leaves that excrete oils, which help fuel fire to make it more intense and detrimental to less heat-adapted species, giving them a natural advantage in the wild.  

Eucalypts have ‘epicormic buds’ under thick bark, which are ready to sprout new stems and leaves after fires to ensure they survive for many years to come.  

Since eucalypts have leaves low in protein and high in toxins, they are predated on by few species, except the koala and eucalyptus leaf beetles like the Chrysomelidae, making them one of the most adaptable and resistant trees in the wild.  

There are over 700 species of eucalypts, and their diversity is reflected in the shapes and sizes of their fruits – from large gumnuts of mottlecah (Eucalyptus macrocarpa), a Western Australian mallee gum, to the tiny capsules of the mountain ash (Eucaltyptus regnans) found on the east coast of Australia.

The brush-like flowers of most Eucalyptus allow open rewards for a wide array of animal pollinators, such as insects, birds and mammals.  

For example, some Australian species such as fuchsia gum (Eucalyptus forrestiana) appear to focus exclusively on bird pollinators. The bizarre long, red, and pendulous flowers of this Western Australian eucalypt make it difficult for insects to access nectar, which means birds can swoop in and access the pollen.