Australia has more than 700 species of native grass, a couple of which will come to the particular notice of walkers.
Spinifex is the hardiest and most common desert plant, forming round clumps of needle-like leaves sprouting into softer, wheat-like seed stalks. The prickly dome is a haven for small desert mammals and reptiles, which shelter inside during the day.
Largely confined to poorly drained plains in southwest Tasmania, buttongrass grows in tall tussocks, separated by bare patches of bog, and is a dirty word among walkers who have ever wallowed through it. Its leaves are tough and the flower for which it is named is a small cluster of white spikelets.Shrubs & Flowers
The best known of the Australian shrubs (and among the easiest to identify) is the callistemon, or bottlebrush. Named for its brush-like flowers, it is found right across the country, and ranges in height from 1m to 10m. There are about 30 species with varying flower colours – red, white, pink and yellow among them – though species are difficult to distinguish. They are a favourite with some birds.
There are around 250 species of grevillea, of which 245 are endemic to Australia. They come in various sizes and flower colours and are found in the Australian Alps, forests, semi-arid country and near the coast. Most are small to medium in size, although the silky oak can grow to 25m and, covered with orange flowers, is one of Australia’s most beautiful trees.
There are around 80 species of tea-tree, which are found in all states. Most species are large, dense bushes, not trees (despite the name). Early settlers gave the tree its name after trying to brew tea using the leaves – what English settler could live without his tea, after all. Flowers are mainly white and stalkless, and leaves are small.
The pandani is the tallest heath plant in the world, and though it looks more like a tropical palm you will only find it in west and southwest Tasmania. It can reach a height of 12m, and has a crown of stiff leathery leaves 1.5m long, with old, dead leaves or fronds forming a huge skirt around the lower trunk.Cycads & Ferns
The MacDonnell Ranges cycad is one of about 25 Australian species of the ancient cycad family. It is very slow-growing, and often found high on rocky hillsides and in gorges. It has palm-like fronds and seed cones grow at the tip of the short trunk on female plants; the male cones carry the pollen. The seeds are poisonous.
The burrawang grows along the NSW coast on sandy soils. The 2m-long palm-like fronds grow from ground level. Its red seeds are also poisonous.
The beautifully ornate rough tree fern and the soft tree fern are found in eastern Australia’s temperate rainforests. Some reach a height of 20m and all are capped by a crown of green fronds.Trees
First among equals for Australian trees is the ubiquitous eucalyptus, or gum tree. Of the 700 species, all but about eight are endemic to Australia. Eucalypts vary in form and height from the tall, ruler-straight karri (confined to WA) and the towering mountain ash to the twisted snow gum. River red gums typically line watercourses, permanent or ephemeral, where their deep roots tap underground water reserves. The most widespread eucalypt, these massive, spreading trees grow to 45m high and can live for hundreds of years. River red gums are notorious shedders of branches, so never camp under this tree; people have been killed by falling branches. The hardy, shrub-like mallee is widespread in the interior. There are more than 100 species of this ground-branching tree, which grows from a massive underground root (lignotuber) that enables it to survive fire. Two of Australia’s most striking trees are eucalypts: the snow gum and the ghost gum. The snow gum flourishes at higher altitudes than any other eucalyptus – up to 1700m in the High Country and Tasmanian highlands. It ranges from 1m to 20m in height and has smooth, whitish bark, sometimes patterned in racing stripes of green, yellow and red. Walkers in the MacDonnell Ranges won’t fail to notice the bone-white trunks of the ghost gum, immortalised in Albert Namatjira’s distinctive paintings.
Australian acacias are commonly known as wattles and around 700 species have been recorded. They vary from small shrubs to the blackwood, which grows up to 30m. The flowers come in all shades of yellow; most species flower during late winter and spring, bringing brilliant splashes of colour to the bush. The golden wattle, with its masses of bright-yellow flowers, is Australia’s floral emblem. A less-showy acacia is the mulga, found across the arid inland. Its wide, funnel-like shape acts as its own water catchment, channelling rain to its base.
Banksias take their name from Sir Joseph Banks, the botanist who accompanied James Cook on his exploration of eastern Australia. Numbering about 70 species and confined to Australia, they are common on sandy soils. Most banksias sport upright cylindrical flower spikes up to 30cm long, covered with vibrant orange, red or yellow flowers. As the flowers die, the woody fruits appear. Aboriginal people dipped the banksia spikes in water to make a sweet drink.
Casuarinas, also known as she-oaks, are hardy trees characterised by wiry ‘leaves’ that are actually branchlets; the true leaves are small scales clustered in whorls at intervals along the branchlets. Casuarinas produce distinctive small knobbly cones. They are widely distributed from the desert to the coast.
The melaleuca, also called paperbark or honey-myrtle, is easily recognised by its pale papery bark, which peels from the trunk in thin sheets. It is widespread on rocky ground, from the coast to semiarid inland areas. The flower spikes consist of many tiny filaments and range from cream through crimson to purple.
Australia has several families of native conifer, but they rarely dominate the vegetation as some pines and spruces do in the northern hemisphere. Endemic to Tasmania, the pencil pine is found in areas of high rainfall: the central plateau and the southwest. A graceful tree, it usually grows to a height of about 15m. Growing in coastal areas and inland semi-arid country in all states except WA, the Oyster Bay pine has distinctive segmented cones and reaches a height of 6m. Foliage is typical of the Callitris genus – tiny scaly leaves arranged along thin branchlets. The cypress pine has hard, furrowed bark and its resistance to termites has made it a favourite bush building material.
The unusual looking grass tree is widespread in southeastern and southwestern Australia, mainly on sandy soils. It has very thin long leaves, a short thick trunk and a distinctive flower spike up to 3m tall, with tiny flowers massed along the upper half of a long stem.
Australia has about 50 species of mangrove – trees and shrubs adapted to daily flooding by salt water. Along northern coasts and estuaries, various species grow to around 30m, while at the southern limit of their distribution, in Victoria, they rarely exceed 5m. Mangroves have various ways of coping with inundation, with some breathing through aerial roots that are exposed at low tide.