Acacia melanoxylon

Acacia melanoxylon, commonly known as the Australian blackwood, is an Acacia species native to south-eastern Australia. The species is also known as blackwood, hickory, mudgerabah, Tasmanian blackwood, or blackwood acacia. The tree belongs to the Plurinerves section of Acacia and is one of the most wide-ranging tree species in eastern Australia and is quite variable mostly in the size and shape of the phyllodes.

Description

A shrub or small tree. It grows 5 m tall. There are prickles along the stem. The leaves are twice divided and there are 8-18 pairs of pinnae. There are up to 50 pairs of pinnules on each pinnae. The flowers are yellow. They are in large clusters at the ends of branches. The pods are flattened.

Edible Uses

The flowers are the edible part. Rich in pollen, they are cooked and often used in fritters. The flowers have a penetrating scent.

Traditional Uses

The gum is eaten. The seed are edible.

This uses section is brief — help expand it

Medicinal Uses

Antirheumatic.

Known Hazards

Indigenous Australians use many parts of A. melanoxylon for a variety of purposes. Seeds are harvested and consumed as a common bush tucker food, and leaves can be used as a soap or fishing poison. The bark is either harvested to make string or prepared as a traditional analgesic, while wood is often used to make clap sticks, spear-throwers and shields. The live plant is also employed as a fire barrier in rural settings when grown amongst other fire-resistant species. Blackwood timber is commercially milled for wood paneling, furniture, joinery and cabinetry, tool handles, boat-building, inlaid boxes and wooden kegs. It is often qualitatively compared to walnut hardwood, and its physical properties are well-suited for shaping with steam. The bark contains a tannin content of about 20%, and is often engineered to produce decorative wood veneer. Plain and figured Australian blackwood is used for musical instruments; in particular, guitars, drums, Hawaiian ukuleles, violin bows and organ pipes. More recently, blackwood has seen an increasing value as a substitute for koa wood.

Distribution

A temperate plant. It occurs naturally in the cooler parts of Australia. It prefers rich loamy soils. It needs a protected position. It cannot tolerate drought. It is resistant to frost. It can stand light shade. In Indonesia it grows between 1,500-2,300 m above sea level. It suits hardiness zones 8-11. Arboretum Tasmania.

Where It Grows

Africa, Algeria, Angola, Argentina, Asia, Australia*, Belgium, Bhutan, Bolivia, Brazil, Britain, Canary Is., Caucasus, Chile, China, Colombia, Congo DR, East Africa, Easter Island, Ecuador, Eritrea, Eswatini, Ethiopia, Europe, France, Greece, Hawaii, Himalayas, India, Indonesia, Italy, Kenya, Lesotho, Mauritius, Mediterranean, Morocco, Mozambique, Nepal, New Zealand, North America, Northeastern India, Pacific, Pakistan, Palestine, Peru, Portugal, Puerto Rico, Reunion, SE Asia, South Africa, Southern Africa, South America, Spain, Sri Lanka, St Helena, Swaziland, Tanzania, Tasmania*, Ukraine, Uruguay, USA, Venezuela, Zimbabwe,

Cultivation

Prefers a sandy loam and a very sunny position. Prefers a deep moist soil. Succeeds in a hot dry position. Succeeds in any good garden soil that is not excessively limey. Most members of this genus become chlorotic on limey soils. This is one of the hardier members of the genus, tolerating temperatures down to about -10°c. It succeeds outdoors in Britain from Dorset westwards, also in south-western Scotland and in Ireland. However, even in the mildest areas of the country it is liable to be cut back to the ground in excessively cold winters though it can resprout from the base. It is planted for timber in south-west Europe. This species produces both phyllodes (basically a flattened stem that looks and acts like a leaf) and true leaves. The roots are very vigorous and extensive - they often produce suckers and can damage the foundations of buildings. This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby.

Propagation

Seed is best sown as soon as it is ripe in a sunny position in a warm greenhouse. Stored seed should be scarified, pre-soaked for 12 hours in warm water, then sown in a warm greenhouse in March; germination takes 3–4 weeks at 25°C. Once seedlings are large enough to handle, prick them out into individual pots and grow on in a sunny greenhouse position through their first winter. Plant out in late spring or early summer after the last expected frosts, with some cold protection recommended for the first winter outdoors. Cuttings of half-ripe wood with a heel can be taken in July or August, potted individually in a frame, overwintered in a greenhouse, and planted out in late spring or early summer. A fair percentage take successfully.

Other Uses

A yellow dye is obtained from the flowers and a green dye from the seedpods. The plant's extensive root system helps prevent soil erosion. The bark is rich in tannin. The wood is hard, dark, close-grained, and high quality, taking a high polish; it is used for furniture and fittings.

Notes

There are about 1,350 Acacia species. Over 1,000 occur in Australia. This one can become invasive. Also as Mimosaceae.

Synonyms

Also Known As

Pohon kayuitem

References (52)

• W. T. Aiton, Hortus kew. ed. 2, 5:462. 1813
• Blamey, M and Grey-Wilson, C., 2005, Wild flowers of the Mediterranean. A & C Black London. p 79
• Bodkin, F., 1991, Encyclopedia Botanica. Cornstalk publishing, p 25
• Bonney, N., 1997, Economic Native Trees and Shrubs for South Australia. Greening Australia (SA) inc. Campbelltown SA 5074 p 11
• Boomsma, C.D., 1972, Native Tree of South Australia. Woods & Forests Department South Australia, Bulletin No.19. p 40

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