Queensland walnut

Scientific name

Endiandra palmerstonii syn. Cryptocarya palmerstonii. Family: Lauraceae.

Local names

Australian walnut, oriental wood, walnut bean, black nut, black walnut.

Description and natural occurrence

This large rainforest tree often reaches a height of 35 m and a stem diameter of 1.8 m. The trunk is well shaped.

It is restricted to the coastal tablelands of North Queensland between Innisfail and Atherton. It is a dominant tree in the rainforest and occurs either singly or in clumps.

Wood appearance

Colour. Heartwood is variable in colour, but usually greyish-brown with streaks of chocolate brown, black or pink. Sapwood is pale yellow and up to 100 mm wide.

Grain. Moderately close and even. Sometimes it is wavy, resulting in a wide variety of figure effects.

Wood properties

Density. 690 kg/m3 at 12% moisture content; approximately 1.5 m3 of seasoned sawn timber per tonne.

Strength groups. (S5) unseasoned; (SD5) seasoned (brackets indicate provisional value).

Stress grades. F5, F7, F8, F11 (unseasoned), F8, F11, F14, F17 (seasoned), when visually stress graded in accordance with AS 2082:2000, Timber - hardwood - visually stress-graded for structural purposes.

Joint groups. JD3 seasoned.

Shrinkage to 12% MC. 4.6% (tangential); 2.1% (radial).

Unit shrinkage. 0.32% (tangential); 0.19% (radial). These values apply to timber of E. palmerstonii 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. Untreated sapwood susceptible to lyctid borer attack.

Termite resistance. Not resistant.

Preservation. Sapwood readily accepts preservative impregnation but penetration of heartwood is negligible using currently available commercial processes.

Seasoning. Slow to dry with some risk of surface checking. Care is needed in drying this species using conventional air and kiln seasoning methods.

Hardness. Moderately hard (rated 3 on a 6 class scale) in relation to indentation and ease of working with hand tools.

Machining. Can be abrasive to machine cutters and hand tools due to the presence of silica in the wood.

Fixing. No difficulty has been experienced with the use of standard fittings and fastenings.

Gluing. Can be satisfactorily bonded using standard procedures.

Finishing. Will readily accept paint, stain and polish.

Uses

Decorative. Plywood, furniture, shop and office fixtures, turnery.

Other. Used for guitar backs and sides.

Identification features

General characteristics

Sapwood. Pale yellow.

Heartwood. Variegated, dark brown with brownish-red to black longitudinal stripes.

Texture. Uniform.

Wood structure

Growth rings. Absent.

Vessels. Medium in size, solitary and in short radial multiples, uniformly distributed; vessel lines distinct on longitudinal surfaces. Tyloses common.

Resin canals. Visible under a lens mostly as irregular apotracheal bands.

Rays. Distinct under a lens.

Other features

Burning splinter test. A match size splinter burns to charcoal.

Figure. Slightly wavy grain is often present, producing attractive figure on quarter-sawn surfaces.

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 06 August 2010