The flora and fauna of Australia has its origin in the ancient continent of Gondwana from which it separated 165 million years ago. This condition of isolation led to the development of a flora and fauna with a high level of endemism.
Australia includes the island of Tasmania and other smaller islands, covering a territory of 7,692,024 Km 2. Most of this territory is desert and semi-arid, with a Mediterranean area to the south and southwest and savannas to the north.
Its climate has a determining influence of the Indian and Pacific oceans, especially the phenomenon of the Niño-Southern Oscillation. The subtropical and tropical climate occurs to the northwest and east and alpine climate in the high elevations.
Under these conditions, Australia has a high biological diversity that makes up at least 30 main vegetation groups. The dominant ecosystems include mound meadows, eucalyptus forests, acacia forests and shrubs, tillering pastures, and halophyte shrubs.
In these, there are 22,000 species of vascular plants and 14,000 of non-vascular plants, with 85% endemism, as well as 250,000 species of fungi. While its fauna includes 378 species of mammals, of which 140 are marsupials and 828 species of birds.
It is also the country with the greatest diversity of reptiles with 775 species, including 140 of snakes and two of crocodiles. It has more than 80% endemism in mammals and reptiles, 45% in birds and two animals (the kangaroo and the emu) are part of its coat of arms.
Flora of Australia
Acacia ( Acacia spp.)
Trees and shrubs of the genus Acaciaof legumes, are characteristic of many plant formations in this country. The species called Golden Beard (Acacia pycnantha), is the plant emblem of Australia with its profuse inflorescences of flowers with showy yellow stamens.
They are perennial plants that unlike other acacias do not have compound leaves, but rather it is reduced to a winged petiole that appears to be simple (phyllodium). The flowers are small with green petals, but the stamens are very long, numerous and showy.
Grass tree ( Xanthorrea spp.)
This genus of 28 species of perennial herbs is endemic to Australia, growing in coastal shrubs and in both wet and dry forests, with yellow latex. Its common name derives from the fact that its underground stem extends into a false hollow stem, formed by the bases of old leaves that reaches several meters in height.
The leaves initially emerge in tufts from the ground and then are raised in a tuft at the apex of the false trunk. The flowers are small dark green, forming a spike on a long central axis called the scape, up to 4 m high.
Common heather ( Epacris impressa )
It is an endemic ericaceae emblem of the state of Victoria in Australia, occurring in southeastern Australia, including Tasmania. It is a shrub from 0.5 to 3 m high, with small rigid leaves with a pointed apex, pink or red white flowers, present in heaths, shrubs, rocky outcrops and forests.
Bottle brush ( Callistemon spp.)
It is another endemic genus of Australia with around 50 species, many of them cultivated as ornamentals in various parts of the world. It belongs to the same family as the eucalyptus (Mirtaceae) and is a very common plant in the humid temperate areas of eastern Australia.
They are shrubs and low-rise trees with flowers with small white or cream petals and numerous long, showy, red or white stamens.
Casuarina ( Casuarina spp.)
They are shrubs and trees with 5 species endemic to Australia, very similar to a pine although they do not bear any relation to them and the trees can reach up to 35 m in height. The Australian species are Casuarina cristata, Casuarina cunninghamiana, Casuarina glauca, Obese casuarina and Casuarina beggar.
The most extreme branches are green and thin giving the appearance of pine needles, the true leaves being small scales. For its part, the small fruits are woody and oval with a certain resemblance to a pine cone and the seeds have a wing.
Eucalyptus ( Eucalyptus spp.)
The most diverse genus of plants in this territory is Eucalyptus, of the Myrtaceae family with around 700 species, almost all endemic. These trees form extensive forests that represent three-quarters of the native forests of this country.
Eucalyptus can be shrubs or trees with one or more stems, from 1 m to more than 100 m in height (Eucalyptus regnans). While multi-stem biotypes that do not exceed 10 m in height are called mallee.
Eucalyptus trees have a bark that peels off in ribbons or scales, their leaves are simple and the flowers have numerous showy stamens. The fruits are small capsules that are opened by a lid that comes off releasing the seeds.
Idiot fruit ( Idiospermum australiense )
This is an endemic tree to the tropical rainforests of Australia, considered a living fossil, representative of the oldest lineages of plants. They are evergreen trees that reach up to 40 m in height and 90 cm in trunk diameter, with simple leaves and small white flowers that turn red when mature.
Its common name derives from the fact of the rareness of the structure of its fruit, since its layers are detached, releasing large naked embryos. These embryos are toxic to livestock.
Macadamia ( Macadamia spp.)
The genus includes 4 species, three of which are of economic interest for their fruits, the called Macadamia nuts. The fourth species,Macadamia jansenii It is in danger of extinction and has toxic fruits due to its high content of cyanogenic glycosides.
The three that produce edible nuts are Macadamia integrifolia, Macadamia ternifolia and Macadamia tetraphylla. They are shrubs or low trees, less than 12 m tall, with leaves in groups of 3 to 6, flowers in long clusters of white, pink or purple and walnut-like fruits.
Kangaroo legs ( Anigozanthos spp.)
This genus of perennial plants groups 11 species all endemic to Australia, growing mainly in dry areas. They develop from an underground stem or rhizome, emerging rosette leaves, these being thin and erect.
From the center of the rosette of leaves, numerous stems of up to 2 m originate bearing panicles of hairy flowers of red, yellow and green colors. These flowers when opened give the impression of being a small foot and hence the name of kangaroo foot.
Prick ( Dendrocnide moroides )
This urticacea is a 1 to 3 m tall shrub endemic to the understory of the Australian rainforests, with fuchsia flowers. Its leaves are covered with glandular hairs that inoculate a neurotoxin on contact.
This toxin is not fatal, but it generates severe pain that lasts for days or even months, forming welts in the contact area. This species is listed as endangered in the New South Wales area.
Spinifex ( Triodia spp.)
It is a genus of perennial grasses that includes about 60 species endemic to Australia, including the smooth spinifex (Triodia pungens) and lobed spinifex (Triodia basedowii). They are grasses that form clumps or tufts that constitute mounds, being the most extensive plant formation in Australia.
They develop in arid areas and have linear leaves up to 40 cm long ending in a stiff, sharp point.
Fauna of Australia
At least 5 endemic species of Australia belonging to the macropod family are known by the name of kangaroo. Among them the red kangaroo (Osphranter rufus), the largest and largest existing marsupial, 1.6 m long plus 1.2 m tail.
These animals move in jumps, being able to reach up to 3 m in height, covering a distance of 9 m in each jump. Its name derives from the reddish-brown color of the coat of the males, since the females are gray.
Then there is the eastern gray kangaroo (Macropus giganteus) somewhat smaller, with gray fur and inhabits the most humid areas of eastern Australia. Additionally there are the western gray kangaroo (Macropus fuliginosus), the antilopine kangaroo (Osphranter antilopinus) and Bennett’s tree kangaroo (Dendrolagus bennettianus).
Southern Cassowary ( Casuarius casuarius )
It is a 190 cm tall walking bird, unable to fly, its plumage is black and dense, similar to a long-haired coat. For its part, the face is light blue and the neck is intense blue with an orange band at the top of the base.
It has a pair of red beards 18 cm long, has a 17 cm crest on the head, the legs are robust with three fingers and a 12 cm spike-shaped claw on the inner finger. It is endemic to the rainforests of Indonesia, New Guinea and northeastern Australia where it feeds on fruits, fungi, insects and small vertebrates .
Saltwater crocodile ( Crocodylus porosus )
This crocodile inhabits Southeast Asia and Australia, being the largest in the world reaching up to 8.5 m in length. Its habitat is rivers, lagoons, sea coasts, estuaries and swamps, being able to propel itself and rise up to the full length of its body.
It feeds on all kinds of prey and even has multiple attacks on humans.
Tasmanian Devil (Sarcophilus harrisii)
This carnivorous marsupial is endemic to the island of Tasmania and southern mainland Australia, and is classified as an endangered species. It is a very ferocious animal when it feeds, it has a high-pitched screech, an unpleasant odor and a very good nose.
The body is robust and compact, about 65 cm in length plus 26 cm of tail, with a proportionally large head and black fur with a transverse white band towards the base. It has another transverse white band on the chest up to the joints of the front legs with the body.
Thorny Devil ( Moloch horridus )
This small lizard, at only 20 cm, is endemic to arid areas of Australia, where it feeds on ants with a sticky tongue. Its name derives from its skin covered with thorns, especially on its head like horns.
It has the ability to camouflage itself by changing color to blend in with its surroundings, like the chameleon. Its main peculiarity is to capture the water from dew or rain on its skin and transport it to its mouth, channeling it with the spines or the legs in the water.
Dugong ( Dugong dugon )
This marine mammal is from the Sirenidae group, being related to manatees and reaching a length of 3 m. Its body is tapered, brown to dark gray, with two pectoral fins and a transverse tail fin.
It is endemic to the marine waters of East Africa, the Persian Gulf, Southeast Asia and Oceania. In Australia it is located along its entire west, north and east coast, where they feed on grasses and seaweed.
Short-billed Echidna ( Tachyglossus aculeatus )
It is also called a spiny anthill, as it feeds on ants and termites, and its body is covered in cream-colored spines. This endemic species of Australia and New Guinea, reaches 45 cm in length and is dark brown or black.
It has an elongated (7.5 cm) and narrow snout that acts as a mouth and nose. The long, sticky tongue allows it to capture insects once it has destroyed their burrows using its powerful digging claws.
Despite being mammals, they reproduce through eggs that are deposited in a bag in the mother’s abdomen until hatching.
Emu ( Dromaius novaehollandiae )
It is an endemic Australian running bird relative to the ostrich, reaching up to 1.9 m in height and 1.64 m in length. Its head and neck are dark bluish in color, with the upper neck section devoid of feathers.
The body is covered with dense grayish-brown fur-like feathers and they preferably inhabit savannas and sparse forests. They feed on leaves, grasses, seeds, and insects.
Koala ( Phascolarctos cinereus )
It is an arboreal marsupial mammal that feeds on young leaves mainly eucalyptus and inhabits the eastern and southern coasts of Australia. Its body reaches up to 85 cm in length and lacks a tail.
It is also covered in gray to dark brown fur long on the back and short whitish on the front. Its head is voluminous in relation to the body and it has rounded and hairy ears, as well as a prominent black nose.
Quol Tiger or Spotted Quol ( Dasyurus maculatus )
It is a partially arboreal carnivorous marsupial, endemic to the northeast, east and south of mainland Australia and Tasmania, whose body reaches a length of up to 93 cm. It has a light reddish brown coat with white rounded spots all over the body, including the tail.
Platypus ( Ornithorhynchus anatinus )
This mammal is endemic to eastern Australia, including the island of Tasmania, and is one of the rarest in the world. It is an amphibian animal of about 50 cm in length, with a flattened body and lateral legs, with a dark brown fur that isolates it from the water.
Together with the echidnas, they are the only mammals that reproduce by means of eggs, they also have a beak similar in appearance to that of the duck. They have webbed feet for swimming, a beaver-like tail and are a poisonous mammal. Males inject a very painful poison for humans, through a spur or spike that they have on their hind legs.
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