Grass Tree Information
(Xanthorrhoea Preissii)
The grass tree is found only in Australia and is very much part of the landscape.
Beautiful specimens, veterans of many fires, may be seen towering their spear like flower spikes 4 to 5 meters high. The flower spikes carry thousands of individual flowers and vary greatly in length.
grass tree in
bush setting
Their blackened trunks may branch once or twice to form compound heads, but more usually a single stem bears a skirt of long grass-like leaves up to a meter or more in length. The long, narrow, tough leaves grow in a crowded manner at the top of the stem and become pendulant as they become older , so that the effect is of tussocks of grass on top of the trunk. The genus is related to the lilies but most botanists favour placing it in a separate family, Xanthorrhoeacea.
The scientific name is derived from the Greek words xanthos (yellow) and rheo (flowing) and describes the yellowish gum commonly found on the plants.
This was used extensively by the Aborigines to attach heads to their spears, and by the early white settlers as a substitute lacquer and varnish.
Grasstrees are found in all the States of Australia. There are a total of 15 species,
7 of which are to be found in Western Australia.
The grasstree is actually more a woody plant than a tree. Its lifespan has been calculated at 600 years, but could even be more. It is very slow growing, the trunk takes a decade or more to form as it is composed of a mass of old leaf bases bound together by the plant's natural resin.
cross section showing
trunk's outer wall,
woody piece and
yellow fibrous material
The trunk itself is hollow with a wall thickness of approx 150mm, leaving a hollow centre , the diameter of the trunk could be 500mm . The root system is grass like, individual roots are up to 5mm dia. and their sheer numbers help to anchor the tree to the ground. The hollow trunk is filled with fibrous material linking the growing top to its food source, the roots.
turned piece,
note spots from
previous leaf ends
The wood-like material sought after by wood turners is only found in the West Australian species Xanthorrhoea Preissii, this species is mostly found in
the southwestern corner of the state. The "wood" is really compressed and bonded fibres, and the spots or dots one sees on a turned piece are the centre marks of the previous leaves. The "grain "pattern is thought to be caused by the different growing conditions e.g. drought, floods and bushfires. The woody piece is formed at the root level, in fact the roots are attached to it, and the fibrous material bonds it together with the trunk.
Unless the grasstree has been dead for several years, and the fibrous material has composted away, it is near impossible to harvest the woody cores. The cores are rarely large enough to make more than one article.
Turning the cores or stumps is dusty , one doesn't cut shavings as with proper wood, just coarse sawdust like dust, which is a health hazard, and proper precautions need to be taken.
In spite of the problems it may cause the wood turner, it is an exciting medium to work with as every piece is so different from the previous one in colour and grain pattern.
last updated 10 Jul 2007
|
|
