Australian Palms

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Australian Palms

In terms of palm diversity, Australia does not have a particularly rich array if we compare the Australian continental land mass to our nearest neighbour, Papua New Guinea, which for such a comparatively small area has an astonishing number of palms. A similar comparison can be made between Africa and Madagascar, the former a huge area with relatively few palm species today, whilst the latter and much smaller area of Madagascar has a rich and varied palm flora far in excess of Africa's. Why does this great disparity exist? It is not possible to state a singular cause, most likely a combination of factors is involved, not the least of which are the increasing aridity of both the Australian and African continents and the massive extensions allowed the grasslands through the regular burning off practised by the human inhabitants since prehistoric times. Africa's palm flora has no doubt also been somewhat reduced by its spectacular evolutionary explosion of herbivorous mammals. A guage of the importance of this trend is the spininess and toughness of the surviving savannah palms, armed against the foraging animals. As most palms have an edible bud, no palm that was not fiercely armed with stout prickles could survive the repeated grazings of such a variety of animals.

Of course, for any place to have a rich palm flora, it must have the ancestral stocks to begin with. In this way Africa and Australia seem to differ, Africa apparently having had a greater stock to begin with whilst Australia seems to have had fewer ancestral lines. Most of the palms occuring here today being extensions of floras from nearby regions. These ancestral lines can be equated with subfamilies, a grouping of plants, in this case, which have a remote common ancestor and today show enough similarities which set them apart from other groups.

The grouping of palms into relationships may seem an abstract scientific concept, but it is useful information that is readily overlooked by the layman. The manner of displaying this concept, a classification system, immediately tells one much about the palms themselves, from it the past histories of the world's continents and much about the environmental adaptability of the palm genera can be read. I will present here a simplified palm classification, showing the position of the Australian palms within the system.

The Australian palms together represent a number of subfamilies which had their origins in an ancient world unlike that which we know today. Most of our palms evolved here, but from lines which came from elsewhere. Australia has no endemic subfamilies, that is none are confined to here. However, we do have a number of endemic genera with affinities in close by and distant regions.

Our present understanding of the native palms is not as complete as we would like. Although we now have a classification system that seems natural and logical, there is still much that has to be learnt about some species and several genera. In order to obtain a meaningful understanding of a palm species one first has to gather a reasonably complete knowledge of its relatives, to ascertain whether the study material represents a distinct species rather than a part of another. Such knowledge may take many years of field work to attain, travelling to remote areas at great expense only to be confronted with difficulties that are unforeseen. Just obtaining the necessary material can be a task and the type of materials desired if available are usually very bulky and difficult to handle.

Presently we know of the existance of at least fifty distinct palm species in Australia, belonging to nineteen genera. There are only six endemic genera, the remaining thirteen can also be found in nearby countries, particularly in Papua New Guinea. Some genera are represented by very few species, indicating either a recent origin of low adaptability, whilst others have numerous species, probably resulting from a longer establishment here or a high ability to adapt. A great array of species from a single genus can also imply a successful colonisation from elsewhere, but in Australia this seems not to be the case.

The Australian palm genera can be summarised according to their origins as follows:

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Extracted from:

Palms of Subequatorial Queensland by Robert Tucker

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