Jarrah
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Jarrah (Eucalyptus marginata) is one of the most common types of eucalyptus trees of southwestern Australia. The species' scientific name marginata refers to the light-colored vein on the border around its leaves. Because of the similar appearance of worked Jarrah timber to the Honduras mahogany tree, Jarrah was once called Swan River mahogany after the river system that runs through Perth. Now it is almost exclusively referred to by its aboriginal name.
Jarrah grows up to 40 m high with a trunk up to 3 m in diameter, and has rough, grayish-brown, vertically grooved, fibrous bark which sheds in long flat strips. The leaves are often curved, 8-13 cm long and 1.5-3 cm broad, shiny dark green above and paler below. The stalked flower buds appear in clusters of 7-11; each bud has a narrow, conical bud cap 5-9 mm long. The flowers are white, 1-2 cm diameter, and bloom in spring and early summer. The fruits are spherical to barrel-shaped, and 9-16 mm long and broad.
The characteristic eucalyptus bark is not shed in patches as it is with many gums, but it splits into fibrous strips. Jarrah trees are also unusual in that they have a lignotuber, a large underground swelling which stores carbohydrates and allows young trees to re-grow after a fire. Because they are deep-rooted (as much as 40 m deep), Jarrah are drought resistant, able to draw water from great depths during dry periods.
Jarrah is an important element in its ecology, providing numerous habitats for animal life, especially birds and bees, while it is alive, but also in the hollows that form as the heartwood decays, and when it falls, it provides shelter to ground-dwellers such as the chuditch (Dasyurus geoffroii), a marsupial cat.
Jarrah is very vulnerable to "dieback", the algae (once thought to be a fungus) Phytophthora cinnamomi, which causes root-rot.
Uses
Jarrah flowers are used to make honey, but its wood is its main use; it is the principal hardwood tree harvested in Oceania for timber. It is a heavy wood, with a specific gravity of 1.1 when green. Its long, straight trunks of richly coloured and beautifully grained termite-resistant timber make it valuable for cabinet making, flooring, and panelling. The finished timber has a deep rich reddish-brown color and an attractive grain. When fresh, Jarrah is quite workable but when seasoned it becomes so hard that conventional wood-working tools are useless. It is very durable, even in wet and weathered situations, making it a choice structural material for bridges, wharves, railway crossties, ship building and telegraph poles.
Jarrah wood is very similar to Karri wood, and as both trees are found in the south west of Australia, the two timbers are frequently confused. They can be distinguished by cutting an unweathered splinter and burning it: karri burns completely to a white ash, whereas jarrah forms charcoal. Most of the best Jarrah has been cut out of South Western Australia. Quite a bit was exported to the United Kingdom, where apparently it was cut into blocks and covered with asphalt for roads. Fortunately, jarrah is much more highly prized these days, and there is now an industry that recyles it from demolished houses. Even so, in 2004, old 4 inch by 2 inch (10 cm by 5 cm) recycled jarrah is routinely advertised in Perth papers for under AUD $1.50 per metre.
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Banu'l Jarrah, was a famous Persian vizier from Khorasan, of the Abbasid dynasty.