Gum trees are the most symbolic of Australia’s plants, winding their way into our songs and stories.
Also known as Eucalyptus trees or Eucalypts, they are as many and as varied as the landscape in which they live.
In recent years the Eucalyptus ‘family’ has been divided up into Eucalypts, Corymbias and Angophoras, but for our purposes today it is as easy to refer to them all as Eucalyptus trees.
Eucalyptus trees are known as Gums because many, but not all, species of Eucalypt exude a thick, sticky red gum from any break in the tree bark. The name Eucalyptus however refers to two Greek words, “eu” meaning “well” and “kalypto” meaning “to cover”. This refers to the cap, or operculum that covers the flower bud when it first develops.
While Eucalypts are seen as being the quintessential Australian tree they are relatively recent arrivals to our shores. The oldest Eucalypt fossils are from South America and are around 51.9 million years old. The oldest reliably dated Eucalyptus fossil in Australia is a 21 million year old tree stump from New South Wales, quite a spring chicken in geological terms.
Biologists think that their arrival coincides with an increase in fossil charcoal deposits suggesting that the burning of Eucalyptus forests was an issue even way back then.
Eucalypts probably remained fairly unimportant in Australian forests until about 20 million years ago when the continent started drying out and soil nutrient levels started to drop.
Modern day Eucalyptus forests cover 92,000,000 hectares of Australia and make up approximately three quarters of the area covered by native forest.
There are more than 700 different species of Eucalypts, Corymbias and Angophoras and most of these are native to Australia.
Eucalypts are well suited to the harsh Australian climate. Specially adapted leaves, thick bark, big underground storage roots called lignotubers and funky under-bark growing tips called epicormic buds all work together to make a plant that can withstand high temperatures, low water availability, fires and low levels of soil nutrients.
Tough, strong and undeniably beautiful there are many different Eucalypts, Corymbias and Angophoras out there and there always seems to be at least one in flower throughout the year. Eucalyptus miniata, the towering ‘Woolly-butt’ tree, is in bloom now, keep an eye out along the highway in between Katherine and Mataranka for its beautiful bright orange blossoms.
