land having extremely specialized floras which are of very great interest to the student of plant geography. While Australia and New Zealand are usually grouped together geographically as "Australasia," they differ much from each other in their vegetation, although having more or less in common. New Zealand is separated from Australia by over a thousand miles of sea, and many of the most characteristic Australian types are quite absent, and others only very sparingly represented. Owing to its very much greater size and range of climate, Australia, as might be expected, possesses a much more extensive flora than the relatively small islands of New Zealand. The completely isolated continent of Australia is almost exactly the size of the continental United States exclusive of Alaska. The Australian climate, however, is very different. The northern portion of Australia is within the tropics, the tip of York Peninsula being only 11 degrees from the equator, while the southernmost part of the continent scarcely touches the fortieth degree of latitude. The adjacent island of Tasmania extends about three degrees further south. The climate is therefore much warmer on the whole than that of the United States or Europe, the coolest regions in the south having a climate comparable to that of California or the Mediterranean. At the north a true tropical climate prevails. The topography of Australia is much less varied than that of the United States. There are no mountains comparable to our great western ranges, and there is a marked dearth of large rivers and lakes. The principal mountain masses are close to the eastern coast, a succession of mountain ranges and highlands extending from the York Peninsula to eastern Victoria and Tasmania. In Queensland there are some definite mountain ranges, but for the most part the high land is a plateau sloping gradually westward, with more or less definite escarpments toward the east. These escarpments sometimes exhibit abrupt gorges cut by the streams. These are well shown in the Blue Mountains west of Sydney. The highest point in Australia is Mt. Kosciusko, 7,300 feet, situated in New South Wales near the Victoria border. This highland region and the adjacent coastal areas have for the most part a good rainfall, but there are no large rivers. The heaviest rainfall is in the coastal region of North Queensland where at certain stations it may exceed two hundred inches annually and averages one hundred and fifty. Inland, however, the rainfall diminishes rapidly, and a third of the continent is said to have ten inches or less annually and another third less than twenty. This means that two thirds of the area of Australia must be classed as desert or semiarid, and much of it unsuited to agriculture, although vast areas are more or less adapted to grazing, which at present in much of the commonwealth is the most important industry. There is a more or less marked wet and dry season in most of Australia, as on our own Pacific coast. In the south most of the rain falls during the winter months, May to September; in the north the heaviest rains fall in the summer. June is the wettest month in the south, January in the north. Northern Australia, lying entirely within the tropics, has for the most part a genuinely tropical climate, hot and humid in the coastal districts. In the more elevated regions of the plateau, however, there may be sharp frost during the winter months, June to August. In August of last year I observed bananas and other tender plants cut down by frost at an elevation of 2,000 to 3,000 feet, in latitude 17°. On the coast, however, frost is quite unknown, and the forest shows a genuine tropical luxuriance. The wettest region in Australia is in northeast Queensland, on the coast, about latitude 17°. In this region a short range of precipitous mountains rises directly from the coast to a height of over 5,000 feet, the highest land in the state. At the foot of this range, the precipitation is very heavy. One place, Babinda, which I visited in August, 1921, had already registered over two hundred inches for the year, and it rained almost incessantly during my stay. The low swampy forest about Babinda was almost impenetrable, the trees loaded down with creepers of various kinds, among which the rattan palms were only too conspicuous. Throughout the eastern tropics the thickets of rattans are a great hindrance to progress in the forest, as their tough, horribly spiny twining stems make absolutely impenetrable tangles, natural barbed-wire barriers. Climbing Aroids and species of Vitis and Piper are also abundant as well as various other lianas. In these wet lowland jungles, the palms reach their fullest development, forming a conspicuous and beautiful feature of the vegetation. One of the commonest and most attractive species is Archontophoenix Cunninghamiana, often cultivated under the name Seaforthia elegans, and one of the most beautiful of all palms, with its smooth slender trunk and crown of graceful feathery leaves. No feature of the Australian vegetation is more beautiful than the groves of these lovely palms. Screw-pines (Pandanus) abound in this region and there are also a number of species of Cycads. Australia is especially rich in these ancient plants. The most widespread genus is Macrozamia, of which there are several species, the genus having representatives in all the states. The two other Australian genera, Cycas and Bowenia, are confined to tropical Queensland. The latter genus, peculiar to Australia, differs much in appearance from any living Cycads, in its solitary bi-pinnate leaves, rather suggesting a bracken fern. In the dryer parts of the Queensland coast the rain-forest is replaced by a more or less mixed forest, composed in part of Eucalyptus, and in part of tropical rain-forest types, like Ficus. A forest of this type may be seen occupying the sandy soil in the neighborhood of Cairns, the principal port of North Queensland. A feature of the coast in this district is the mangrove formation along the shore and the banks of the streams flowing into the sea. Several genera are represented, the most important being the widespread Rhizophora and Avicennia. Some interesting ferns were noted in this region, the most striking being a gigantic Angiopteris which was seen in several places in the vicinity of Babinda. Immediately back of the coast the land rises rapidly to a plateau reaching an extreme elevation of about 4,000 feet, but averaging 2,000 to 3,000 feet over most of its extent. This table-land has an ample rainfall, and on the better soils develops a fine forest which yields extremely valuable timber. Much of the timber has been destroyed, but there are still some remnants which are accessible, and these are really magnificent examples of tropical forest growth. This tropical rain-forest is known in Queensland by the very inappropriate name of "Serub" and is confined to the rich basaltic and alluvial soils. The trees of this forest are mainly of Malayan affinity, and are tall with lofty straight trunks yielding a large amount of fine timber. Some of them, especially the Kauri (Agathis Palmerstoni) and "Red Cedar" (Cedrela toona) reach a very large size. The latter was formerly abundant and sometimes attained a diameter of upwards of ten feet. It has been largely exterminated, but an occasional fine specimen may still be seen, and the same is true of the Kauri. Belonging to the same family (Meliaceae) as the cedar are several species of Flindersia, which are locally known as "hickory," "maple," "beech," and other woods not in the least related to them. Other characteristic trees are Elaeocarpus, (Tiliaceae), Aleurites Moluccana, widespread throughout Polynesia; Sideroxylon (Sapotaceae), Eugenia (Myrtaceae) and others. The characteristic Australian family Proteaceae is represented in the rainforest by several species of Grevillea, Stenocarpus, Macadamia and other genera. Grevillea robusta of southern Queensland is often grown in California as an ornamental tree. This upland forest has much finer trees than the lowland forest |