|Australian National Botanic Gardens
EUCALYPT DISCOVERY WALK
Discover a selection of Australia’s iconic eucalypts
EUCALYPT DISCOVERY WALK
Discover a selection of Australia’s iconic eucalypts as you follow this self-guided walk.
List of trees
1. Eucalyptus cunninghamii – Cliff Mallee Ash
2. Eucalyptus globulus – Tasmanian Blue Gum
3. Eucalyptus regnans – Mountain Ash
4. Eucalyptus melliodora – Yellow Box
5. Corymbia ficifolia ‘Dwarf Orange’
6. Eucalyptus mannifera – Brittle Gum
7. Eucalyptus lacrimans – Weeping Snow Gum
8. Eucalyptus scoparia – Wallangara White Gum
9. Eucalyptus benthamii – Camden White Gum
10. Eucalyptus polybractea – Blue Mallee
11. Eucalyptus robusta – Swamp Mahogany
12. Eucalyptus rossii – Scribbly Gum
13. Eucalyptus pulverulenta – Silver-leaved Mountain Gum
14. Corymbia calophylla – Marri
15. Eucalyptus saligna – Sydney Blue Gum
16. Corymbia citriodora – Lemon-scented Gum
17. Eucalyptus siderophloia – Northern Grey Ironbark
18. Eucalyptus cloeziana – Gympie Messmate
19. Angophora costata – Smooth-barked Apple
20. Eucalyptus viminalis – Manna Gum
21. Eucalyptus grandis – Flooded Gum
Walk time: 1 hour
Walk distance: 1.8 km
Note: walk traverses stairs, lawn and uneven surfaces
KEY FACTS ABOUT EUCALYPTS
Eucalypts are a defining feature of much of the Australian landscape and an essential part of Australian culture. They dominate the tree flora of Australia and provide habitat and food for many native animals.
Of the over 850 eucalypt species known, almost all are native only to Australia.
Some species have a wide geographic distribution; others are extremely restricted in their natural habitat and need conservation.
NOT ALL EUCALYPTS ARE EUCALYPTUS
The term ‘eucalypt’ refers to three closely-related genera of the Myrtaceae family – Eucalyptus with 758 species, Corymbia with 93 species and Angophora with 10 species. Colloquially they are called ‘gum trees’.
Eucalyptus is derived from the Greek eu- meaning ‘well’ and kalyptos meaning ‘covered’, referring to the small cap or lid (operculum) which covers the flower bud before it blooms in Eucalyptus and Corymbia.
Angophora species have no flower bud cap. The name Angophora comes from the Greek phora meaning ‘carries’ and angos meaning ‘jar’ or ‘vessel’ refering to the cup-shaped fruit borne by members of the genus.
The genus Corymbia is named from the Latin corymbium; a ‘corymb’ refers to the form of the flower clusters.
Eucalypts show a great diversity of size, form, leaf and bark type. Each of these characteristics help in their identification. Species featured in this walk illustrate the diversity and many uses of eucalypts.
Eucalypts have tough leathery leaves that often hang vertically to minimise exposure to the sun and moisture loss. They are rich in volatile oils, making them vulnerable to bushfires.
The leaf form changes from seedlings to maturity. In most species there is a pronounced difference between the juvenile, intermediate and adult leaves. Generally, the mature leaves of Eucalyptus and Corymbia are alternate. Angophora leaves grow opposite each other.
Look for the different shapes and textures of the gum tree leaves. Do the leaves grow opposite each other, or do they alternate?
There is great variation in eucalypt fruits (gum nuts). The fruit is usually a woody capsule and may be small or very large, single or clustered.
Typical Eucalyptus fruit
Most Corymbia species have thick-walled woody fruit that are more or less urn-shaped
Angophora species have ribbed fruit
Look for gum nuts near eucalypt trees as you walk through the Gardens. Can you tell the difference between Eucalyptus, Angophora and Corymbia fruits?
As well as having great beauty, eucalypt bark can help in a tree’s identification. At a popular level, many people use bark to help identify eucalypts. Bark types are often used in the common names of eucalypts.
Mature eucalypts vary in bark characteristics.
Smooth-barked species shed their bark annually in strips, flakes or slabs revealing a colourful, fresh, smooth trunk. Other species have rough bark that persists for many years giving the trunk a rough and often dark-coloured appearance.
Rough bark may be referred to by its texture, such as compact, tessellated, stringy or ironbark. Rough bark may be present only on part of the trunk, with branches and upper trunk being smooth.
Feel the different textures of the gum tree barks.
EVOLUTION OF EUCALYPTS
Eucalypts are thought to have evolved from rainforest species in response to great changes in the landscape, soils and climate of the continent. As the environment became drier, eucalypts adapted to live in challenging conditions of variable rainfall, low nutrient soils and high fire risk existing over much of the continent. They grow from the arid inland to temperate woodlands, wet coastal forests and sub-alpine areas.
ADAPTED TO FIRE
Dormant epicormic buds hidden beneath the often thick insulating bark of most eucalypts are ready to sprout new stems and leaves after fire. All but a few eucalypts have a special structure at the base of the trunk known as a lignotuber which also contains dormant buds and nutrients protected from fire. Some species rely on seeds released by gum nuts following fire to produce seedlings in the nutrient-rich ash bed.
IMPORTANT TO WILDLIFE AND PEOPLE
Eucalypts are important for wildlife habitat. Tree hollows and bark provide nesting and refuge sites for native animals. Leaves, nectar, pollen and seeds are all important food sources for many native animals.
Eucalypts are a vital resource of the Australian environment. They have many commercial uses including wood products, pulp and paper production, honey and eucalyptus oil. They are the world’s most widely planted hardwoods.
Indigenous Australians have long used eucalypts for medicinal purposes, food and tools as well as shields, dishes, musical instruments and canoes.
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