About 400 species of eucalyptus trees occur in Australia, ranging from the giant trees of the Victorian mountain forests to the dwarf mallees of the south coast. Their graygreen foliage is the dominant color in the landscape of most coastal regions. In moist regions a rich ground cover of ferns is commonly associated with the dense tree growth. In drier areas the eucalypts occur as an open forest growth with an intermixture of woody shrubs and grasses. They are also found growing as gallery forests along the banks of rivers in the interior, such as the Murray and its major tributaries.
Many of the eucalypts are highly inflammable, and some of the most valuable species have been seriously damaged by forest fires. Eucalypts provide the bulk of wood used in Australia for ordinary construction purposes and fuel. Large areas of eucalyptus forests have been destroyed by "ring-barking" operations in order to extend the pasture and crop areas. The various species of eucalyptus are known to Australians by a variety of common names such as ironbarks, gums (smooth barks), half barks (boxes), stringybarks, and peppermints. The brilliant red flowers of certain eucalypts in Western Australia are conspicuous for their beauty in contrast to the small white flowers of most eastern species.
Outstanding among the eucalyptus timber trees are the so-called mountain ash (Eucalyptus regnans) of the Victorian uplands and the karri (Eucalyptus diversicolor) and jarrah (Eucalyptus marginata) forests of Western Australia. The 4,000,000 acres of karri and jarrah forests comprise one of the most important forest regions in Australia.
The forests of Tasmania resemble those of the highlands in Victoria. However, in addition to large stands of eucalyptus, dense growths of myrtle beech (Nothofagus) forests occur on the western uplands.
The mallee is a species of dwarf eucalyptus characteristic of a wide belt along the south coast from Victoria to Western Australia. Bushy growths, 20 feet or less in height, cover large areas of subhumid sandy land. The mallee is often cleared by wheat farmers by rolling it down and burning the tangled growth. Serious soil drift often follows such operations. The bulky roots of mallee are commonly used as firewood.