794
AUSTRALIA
[flora perfectly bare, and there is no water. Nothing could add to the sterility and the monotony of these mallee scrubs. “Mulga” scrub is a somewhat similar thicket, covering large areas. The tree in this instance is one of the acacias, a genus distributed through all parts of the continent. Some species have rather elegant blossoms, known to the settlers as “wattle.” They serve admirably to break the sombre and monotonous aspect of the Australian vegetation. Two species of acacia are remarkable for the delicate and violet-like perfume of their wood—myall and yarran. Proteaceous plants, although not exclusively Australian, are exceedingly characteristic of Australian scenery, and are counted amongst the oldest flowering plants of the world. The order is easily distinguished by the hard, dry, woody texture of the leaves and the dehiscent fruits. They are found in New Zealand and also in New Caledonia, their greatest developments being on the south-west of the Australian continent. Proteacese are found also in Tierra del Fuego and Chile. They are also abundant in South Africa, where the order forms the most conspicuous feature of vegetation. The range in species is very limited, no one being common to eastern and western Australia. The chief genera are banksia {honeysuckle), and hakea {needle hush). The well-known Moreton Bay pine {Araucaria Cunninghamii) is reckoned amongst the giants of the forest. The genus is associated with one long extinct in Europe. Moreton Bay pine is chiefly known by the utility of its wood. Another species, A. Bidunllii, or the bunya-bunya, afforded food in its nut-like seeds to the aborigines. A most remarkable form of vegetation in the northwest is the gouty-stemmed tree, one of the Malvaceae. It is related closely to the famous baobab of tropical Africa. The “grass-tree” {Xanthorrhcea), of the uplands and coast regions, is peculiarly Australian in its aspect. It is seen as a clump of wirelike leaves, a few feet in diameter, surrounding a stem, hardly thicker than a walking-stick, rising to the height of ten or twelve feet. This terminates in a long spike thickly studded wdth white blossoms. The grass-tree gives as distinct a character to an Australian picture as the agave and cactus do to the Mexican landscape. With these might be associated the gigaiitic lily of Queensland {Nymphcea gigantea), the leaves of which float on water, and are quite eighteen inches across. There is also a gigantic lily {Doryanthes excelsa) which grows to a height of 15 feet. The “ flame tree ” is a most conspicuous feature of an Illawarra landscape, the largest racemes of crimson red suggesting the name. The waratah or native tulip, the magnificent flowering head of which, with the kangaroo, is symbolic of the country, is one of the Proteaceae. The natives were accustomed to suck its tubular flowers for the honey they contained. The “ nardoo ” seed, on which the aborigines sometimes contrived to exist, is a creeping plant, growing plentifully in swamps and shallow' pools, and belongs to the natural order of Marsiliacese. The spore-cases remain after the plant is dried up and withered. These are collected by the natives, and are known over most of the continent as nardoo. No speculation or hypothesis has been propounded to account satisfactorily for the origin of the Australian flora. As a step towards such hypothesis it has been noted that the Antarctic, the South African, and the Australian floras have many types in common. There is also to a limited extent a European element present. One thing is certain, that we have in Australia a flora that is a remnant of a vegetation once wddely distributed. Heer has described such Australian genera as Banksia, Eucalyptus, Grevileea, and Hakea from the Miocene of Switzerland. Another point agreed upon is that the Australian flora is one of vast antiquity. We have here genera so far removed from every living genus that many connecting links must have become extinct. The region extending round the south-western extremity of the continent has a peculiarly characteristic assemblage of typical Australian forms, notably a great abundance of the Proteacese. This flora, isolated by arid country from the rest of the continent, has evidently derived its plant life from an outside source, probably from lands no longer existing.
Flora. To understand the distribution of plants in Australia, one must always bear in mind that the central valleys and plateaux are surrounded by physical conditions totally difi'erent from those prevailing on the coastal plains, and that the northern part of the continent has been invaded by a number of plants characteristically Melanesian. This element was introduced via Torres Strait, and spread down the Queensland coast, and also round the gulf of Carpentaria, but has never been able to obtain a hold in the more arid interior. Judging by the plants alone, and to a great extent by the animals, nobody could tell, when in a Queensland coastjungle, whether he were in Australia or New Guinea. Travellers often describe the wonderful wealth of plant life in the eastern coast-line, but this must not be taken as indicating the nature of the flora inland in the same latitude. In the interior there is little change in the general aspect of the vegetation, from the Australian Bight to the region of Carpentaria when the exotic element begins. Behind the luxuriant jungles of the Queensland coast, once over the Main Range, we lind the purely Australian flora with its apparent sameness and sombre dulness. Physical surroundings rather than latitude determine the character of the flora. The contour lines showing the heights above sea-level are the directions along which species spread to form zones. Putting aside the exotic vegetation of the north and east coast-line, the Australian bush gains its peculiar character from the prevalence of the so-called gum-trees {Eucalyptus) and the acacias, of which last there are 300 species. But the eucalypts above all are everywhere. Stunted eucalypts fringe the tree limit on Mount Kosciusko, and the soakages in the parched interior, which pass on maps for rivers, are indicated by a line of the same trees, stunted and straggling. Over the vast continent from Wilson’s Promontory to Cape York, north, south, east, and west—where anything can grow—there will be found a gum-tree. The eucalypts, so typical of the Australian bush, are remarkable for the oil secreted in their leaves, and the large quantity of astringent resin of their bark. This resinous exudation (Kino) somewhat resembles gum, hence the name “gum” tree. It will not dissolve in water as gums do, but it is soluble in alcohol, as resin usually is. Many of the gumtrees throw off their bark, so that it hangs in long dry strips from the trunk and branches, a feature familiar in “bush” pictures. The bark, resin, and “oils” of the eucalyptus are well known as commercial products. As early as 1866, tannic acid, gallic acid, wood spirit, acetic acid, essential oil and eucalyptol, were produced from various species of eucalyptus. The genus eucalyptus numbers more than one hundred and fifty species, and provides some of the most durable timbers known. The iron-bark of the eastern uplands is well known {Eucalyptus sideroxylon), and is so called from the hardness of the wood, the bark not being remarkable except for its rugged and blackened aspect. Samples of this timber have been studied after forty-three years’ immersion in sea water. Portions most liable to destruction, those parts between the tide marks, were found perfectly sound, and showed not the slightest sign of the ravages of marine organisms. The well-known Jarrah {Eucalyptus marginata) of West Australia is one of the most durable of timbers ; 14,000 square miles of country are covered with this species. This tree has been known to grow to 10 feet in diameter and 120 feet in height. The timber is nearly impervious to the attacks of the teredo. There is good evidence to. show that, exposed to wear and weather, or placed under the soil, or used as submarine piles, the wood remained intact after nearly fifty years’ trial. The following figures show the high density of Australian timber:— Australian Specific Australian Specific Timber. Gravity. Timber. Gravity. Jarrah . . . U12 Tallow wood . . 1 ‘23 White iron-bark . 1J7 Mahogany . .1-20 Red iron bark . .1-22 Grey gum . . -917 Forest oak . . l^l Red gum. . . -995 European Specific Fauna. European Specific Timber. Gravity. Timber. Gravity. More than a hundred marsupials, or about two-thirds of the Ash . . . -753 Ebony . . . 119 known species, are natives of Australia. The kangaroo {Macropus), Beech . . . ’690 British oak . . -99 emblematic of the island continent, lives in droves in the open Chestnut . . . -535 grassy plains of the interior. Several smaller forms of the same are known as wallabys, and are common everyYarious scrubs characterize the interior, differing very general appearance Other terrestrial marsupials are the wombat {Phascolomys), widely from the coastal scrubs. “Malice” scrub occupies large awhere. large clumsy burrowing animal, not unlike a pig, which attains a tracts in South Australia and Victoria, coverin" probably an weight from 60 to 100 lb ; the bandicoot {Perameles), a rat-like extent of 16,000 square miles. The malice is a species of euca- creatureofwhose annoy the agriculturist; the native lyptus growing 12 to 14 feet high. The tree breaks into thin cat {Dasyurus), depredations noted robber of the poultry yard ; the Tasmanian stems close to the ground, and these branch again and a^ain the wolf (Thylacinus), which preys on large game; and the recentlyleaves being developed umbrella-fashion on the outer branches. Notoryctes, a small animal wdiich burrows liker a mole in The mallee scrub appears like a forest of dried osier, growing so discovered the interior. Arboreal species include the w ell-known close that it is not always easy to ride through it. Hardly a leaf is the desert of{Phalanger)
- the extraordinary tree-kangaroo of the
visible to the height of one’s head ; but above, a crown of thick opossums Queensland tropics; the flying-squirrel, which expands a membrane leather-like leaves shuts out the sunlight. The ground below is ' between the legs and arms, and by its aid makes long sailing
