Bunya pine

Scientific name

Araucaria bidwillii Hook. Family Araucariaceae

Local names

Bunya pine

Description and natural occurrence

A tall softwood tree attaining 30 to 45 m in height and up to 1.5 m in diameter. The straight trunk is often free from branches for two-thirds the height. The distinctive crown is symmetrical and domed, changing from a pointed to a flattened apex with age. The branches are unbranched and the leaves are clustered at the ends. The bark is dark brown to black and persistent with thin scales. The leaves have either very short petioles or none, are lanceolate, sharply pointed, 2-5 by 0.5-1 cm, hard and glossy green. Cones and seeds are very much larger than those of other Australian softwood species. The seeds are edible.

Bunya pine occurs mainly in southeastern Queensland between Gympie and the Bunya Mountains northeast of Dalby. There are also small, isolated occurrences on Mt. Lewis and at Cunnabullen Falls in northern Queensland. It grows in moist valley floors as well as upper slopes and ridgetops in the ranges within about 160 km of the coast. It is normally an emergent over rainforest, often in association with hoop pine.

Timber is not readily available as trees are only removed for safety reasons or because they are in poor health. Small plantings have been established adjacent to hoop pine plantations, particularly in frost-free zones. The timber is sought after for guitar soundboards.

Wood appearance

Colour. Similar to hoop pine but slightly pink. The heartwood is pale brown, sometimes with pink or cream streaks. The sapwood is not clearly distinguishable.

Grain. Fine, even texture and a straight grain. Growth rings are faint.

Wood properties

Density. 530 kg/m3 at 12% moisture content; approximately 1.7 m3 of seasoned sawn timber per tonne.

Strength groups. S6 unseasoned; SD5 seasoned.

Stress grades. F4, F5, F7, F8 (unseasoned), F7, F8, F11, F14, F17 (seasoned), when visually stress graded in accordance with AS2858-2000, Visually stress-graded softwoods for structural purposes.

Joint groups. J4 unseasoned; JD4 seasoned.

Shrinkage to 12% MC. 4% tangential; 2% radial.

Unit shrinkage. 0.23% (tangential); 0.11% (radial). These values apply to timber reconditioned after seasoning.

Durability above-ground. Class 4 - life expectancy less than 7 years.

Durability in-ground. Class 4 - life expectancy less than 5 years.

Lyctine susceptibility. Not susceptible.

Termite resistance. Not resistant.

Preservation. Heartwood is relatively easy to impregnate with preservatives.

Seasoning. Dries rapidly but precautions against bluestain are necessary.

Hardness. 1.7 kN green, 2.3 kN dry (Janka hardness).

Machining. Easy to work.

Gluing. Glues well.

Uses

General purpose softwood used in plywood, interior joinery, linings, mouldings, furniture and general, interior construction.

Others. Musical instruments, especially guitars.

Identification features

Sapwood. Indistinguishable from heartwood.

Heartwood. Pale yellow-brown to pink.

Texture. Fine and even.

Rays. Very fine and indistinct.

Burning splinter test. A splinter burns moderately well, with occasional faint crackling and a brownish exudation. Embers die fairly quickly, leaving a thin, tawny brown ash.

Gum veins. Absent.

Further reading

Boland, DJ, Brooker, MIH, Chippendale, GM, Hall, N, Hyland, BPM, Johnston, RD, Kleinig, DA and Turner, JD 2006, 'Forest trees of Australia', 5th edn, CSIRO Publishing, Collingwood Australia.

Bootle, K 2005, 'Wood in Australia: types, properties and uses', 2nd edn, McGraw-Hill, Sydney.

Hopewell, G (ed.) 2006, 'Construction timbers in Queensland: properties and specifications for satisfactory performance of construction timbers in Queensland, Class 1 and Class 10 buildings', books 1 and 2, Department of Primary Industries and Fisheries, Brisbane.

Ilic, J 1991, 'CSIRO atlas of hardwoods', Crawford House Press, Bathurst, Australia.

Standards Australia, 2000, 'AS 2082-2000: Timber - hardwood - visually stress-graded for structural purposes', Standards Australia.

Last updated 25 August 2010