''Allocasuarina luehmannii'' (buloke or bull-oak) is a species of

ironwood Ironwood is a common name for many woods or plants that have a reputation for hardness, or specifically a wood density that is heavier than water (approximately 1000 kg/m3, or 62 pounds per cubic foot), although usage of the name ironwood in E ...

tree native to Australia and its wood is the hardest commercially available as measured by the Janka Hardness Scale.

Description

The evergreen tree typically grows to a height of and usually produces a clear trunk. It is moderately to long-lived, usually over 15 years with a moderate growth rate. It is

dioecious Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproductio ...

with male and female flowers on separate plants, which flowers in spring. It is cited as having the hardest wood in the world, with a

Janka hardness The Janka hardness test (; ), created by Austrian-born American researcher Gabriel Janka (1864–1932), measures the resistance of a sample of wood to denting and wear. It measures the force required to embed an steel ball halfway into a sample ...

of 22,500 N (5,060 lbf). However
The Wood Database
gives it a Janka hardness of only 16,600 N (3,760 lbf):

"Australian buloke is commonly reported as the hardest wood in the world. This is based upon a single data source and may not give the best representation of all testing and data available. Consequently, with as many data points taken into consideration as possible, Australian buloke ranks at #21 overall on the poster Worldwide Woods, Ranked by Hardness. For more information, please consult the video discussion, Quest for the Hardest Wood in the World."

The cladodes are long with 10 to 14 teeth. They are sometimes waxy, of slightly greater diameter near their apex than their base.

Distribution

The species occurs across a vast region of eastern and southern Australia, mainly north and west of the Great Dividing Range, within the Murray-Darling Basin, and within the states of

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

South Australia South Australia (commonly abbreviated as SA) is a state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest of Australia's states and territories ...

and Victoria. Its extent of occurrence has been greatly depleted by clearing for cereal cropping and pasture development. It is an important food resource for the endangered southeastern subspecies of the red-tailed black cockatoo in the Wimmera region of western Victoria, where some remnant stands are threatened by farming practices It grows on a range of soil types, mainly sandy loams, and is usually found on lower parts of the landscape. It tolerates acid, alkaline and moderately saline soils. The Shire of Buloke in

Victoria, Australia Victoria is a state in southeastern Australia. It is the second-smallest state with a land area of , the second most populated state (after New South Wales) with a population of over 6.5 million, and the most densely populated state in Au ...

is named after this tree species.

Classification and naming

The species was first formally described as ''Casuarina luehmannii'' in 1900 by the

botanist Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek wo ...

Richard Thomas Baker in the paper ''On two new species of Casuarina'' in the ''Proceedings of the Linnean Society of New South Wales''. It was subsequently reclassified in the ''Allocasuarina'' genus by

Lawrence Alexander Sidney Johnson Lawrence Alexander Sidney Johnson FAA, (26 June 1925 – 1 August 1997) known as Lawrie Johnson, was an Australian taxonomic botanist. He worked at the Royal Botanic Gardens, Sydney, for the whole of his professional career, as a botanist (1948 ...

in 1985 in the ''Journal of the Adelaide Botanic Gardens''. The Wiradjuri people of

use the name ''Ngany'' to refer to the species.

Aboriginal uses

The Wiradjuri people of NSW use the timber and resinous sap to make a range of tools and other implements, including weapons such as boomerangs and clubs. Wiradjuri people also value the species due to its ability to attract many animals that are food sources, such as possums and birds.

Gallery

File:Allocasuarina luehmannii.jpg, Bull oak tree, coastal Central Queensland. File:Allocasuarina Ieuhmannii shoot.jpg, Tree shoots

References

External links

Occurrence data for ''Allocasuarina luehmannii''
from The Australasian Virtual Herbarium {{Taxonbar, from=Q2838513 luehmannii Fagales of Australia Flora of New South Wales Flora of South Australia Flora of Victoria (Australia) Trees of Australia Drought-tolerant trees Dioecious plants