The iconic eucalyptus

Depending on which reference you use, there are between 700 and 900 species of Australia’s iconic eucalyptus tree. Something like 75% of our forests are made up of eucalyptus species, (next is the acacias and then the melaleucas). Eucalypts grow on tops of mountains, on the coast, in high rainfall gullies and on dry mallee and mulga plains.

Although considered to be endemic to Australia, naturally occurring eucalypts are found in New Guinea, Timor and parts of the Philippines. The genus is cultivated world-wide now, and in some places has become naturalized.

In 1777, a botanist sailing with Captain James Cook collected samples from Tasmania’s Bruny Island. In 1788, a French botanist identified and named the first species, Eucalyptus obliqua, more commonly known now as Messmate.

Proper identification of eucalypts is not easy at times and requires a certain amount of botanical knowledge about the bark, the fruit, the flowers and the leaves. Matters are made more complicated when it is accepted that some species are known to hybridize. Many factors come into play for the proper identification of eucalypts:

          Geographical location – elevation or depression, coastal, alpine, etc.

          Habit – tall and straight, small, spreading, single or multi-trunked, etc.

          Bark – colour, form and consistency.

          Flower and fruit – colour, size, shape and arrangement.

Leaf – colour, lustre, size, shape, arrangement, juvenile/adult and even the arrangement of the veins and oil glands.

(The glossary for one common text on eucalypts contains definitions of over 250 botanical terms!) 

Many of our eucalypts have learned to deal with fire by re-sprouting from buds under the bark or from tubers at the base of the tree.

Eucalypts are a valuable and important species for many reasons. Like all trees, they provide shade, lower the water table, purify the air and sequester carbon. Eucalypts are notable for their oils, fibre and timber and of course, many native birds and animals are entirely dependent on eucalypt habitat.

Not only iconic, but invaluable!