Facts About the Eucalyptus Tree - Description and Uses
Eucalyptus trees are evergreen trees. They are one amongst the oldest trees that existed on earth about 50 million years ago. Eucalyptus trees are native to Australia and are also referred to as “gum trees”.
Eucalyptus trees belong to the Eucalyptus genus and have more than 600 species. They can grow up to a height ranging from 30 -300 feet tall. They belong to the Myrtle family.
They are cultivated in the tropical and sub-tropical regions in Australia, America, Europe, India, Africa, Philippines, Indonesia and New Guinea.
Characteristics of the Eucalyptus Tree
Eucalyptus trees are usually single-stemmed. Some trees branch out after growing a short distance from the ground.
Eucalyptus trees referred to as “Mallees” are multi-stemmed from ground level. They are usually about 10 m in height. Some of the Mallees grow very close to the ground resembling shrubs.
The bark of the Eucalyptus tree varies with the age of the tree. Every year the trunk of the Eucalyptus tree grows an extra layer that increases the thickness of the trunk. The older layer dies and is shed off slowly.
In many species, the dead bark is retained. The outermost layer of the dead bark weathers down gradually giving a different texture to the bark as they shed off.
Stringybark – This bark has long strips of the dead trunk which can be easily peeled off.
Ironbark – This bark is deeply fissured and very hard. The sap oozes out through these cracks and dries on the bark that gives the appearance of a dark red to black color to the trunk.
Tessellated – This bark is broken up into many distinct flakes.
Eucalyptus regnans (Australian Mountain Ash) is the tallest of all the flowering plants in the world.
Eucalyptus trees that exceed 80 m in height are – Eucalyptus oblique, Eucalyptus delegatensis, Eucalyptus diversicolor, Eucalyptus nitens, Eucalyptus globulus and Eucalyptus viminalis.
Eucalyptus trees do not grow very well in cold climates. They can only tolerate cold temperature up to -5 degrees centigrade. Eucalyptus pauciflora is an exception and can grow in temperatures as low as -20 degrees centigrade.
Leaves of the Eucalyptus trees are long, narrow and leathery covered with oil glands. The leaves are arranged opposite to one another in pairs. The consecutive pairs are at right angles to each other. Each leaf has a small stalk called the petiole.
Flowers of the Eucalyptus tree are unique. They do not have any petals but are covered by feather-like stamens that may be white, pink, yellow or red in color.
The fruit is surrounded by a woody, cup-shaped receptacle that contains many seeds.
Many of Eucalyptus trees have lignotubers on the crown of their roots. The lignotubers store food and can sprout new shoots. Eucalyptus trees can grow back easily after forest fires due to these lignotubers that lie buried deep in the soil and are not affected by the forest fires.
One significant disadvantage of the Eucalyptus trees - On warm sunny days the Eucalyptus oil on the leaves vaporizes and reaches the upper layer of the atmosphere. Eucalyptus oil is highly flammable and due to this reason it very easy for forest fires to spread out from one tree to another and cause significant damage.
The many uses of the Eucalyptus tree
1. Eucalyptus oil is extracted from the leaves by steam distillation. This oil is anti-fungal, antimicrobial, anti-inflammatory, decongestant, antiseptic, antispasmodic and has other medicinal uses. Eucalyptus oil is colorless with a distinct taste and odor.
2. Eucalyptus oil is used in many medicines to treat a cough and cold. It is also used in lozenges, rubs, cough syrups, and vapor baths. Eucalyptus globulus trees are a primary source from which Eucalyptus oil is extracted.
3. Vapor rubs containing Eucalyptus oil are used to relieve congestion.
4. The oil is also used to loosen phlegm and relieve nasal congestion during steam inhalation.
5. Eucalyptus oil is rich in an antiseptic called cineole. Cineole kills bacteria that causes bad breath and is used in antiseptic mouthwashes.
6. It is rubbed on the knees and joints to relieve arthritis.
7. Eucalyptus oil is also used in aromatherapy.
- Eucalyptus trees are used to produce pulpwood. This pulpwood is used to make fine papers and soft tissue papers.
- Eucalyptus globulus and Eucalyptus grandis are mostly used to make paper because their fibers are short in length and are less coarse and uniform.
- Eucalyptus oil is used in many insect repellents.
- Koala bears eat all parts of the Eucalyptus trees.
- The bark of the Eucalyptus trees is used to make digeridoos, a traditional Aboriginal wind instrument.
- All parts of the Eucalyptus trees are used to make dyes that are used on wool and silk fibers.
- The wood of a Eucalyptus tree commonly known as “Jarrah” is very durable, fire and worm resistant. It is used to make boats, piers, furniture, flooring, telephone poles, tool handles, etc.
- Eucalyptus trees draw tremendous water from the ground. They have been planted to lower the water table.
Eucalyptus is truly a wonder tree with many uses and great benefits.
© 2012 Nithya Venkat