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Queensland walnut

Scientific name

Endiandra palmerstonii syn. Cryptocarya palmerstonii. Family: Lauraceae

Other names

Australian walnut; oriental wood; walnut bean; black nut; black walnut

Description

  • Large rainforest tree.
  • Often grows 35m high.
  • Stem to 1.8m diameter.
  • Trunk is well shaped.

Occurrence

  • Restricted to the coastal tablelands of North Queensland between Innisfail and Atherton.
  • Dominant tree in the rainforest and occurs either singly or in clumps.

Appearance

Colour

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

Grain

  • Moderately close and even; but sometimes wavy, resulting in a wide variety of figure (pattern) effects.

Uses

  • Decorative: plywood, furniture, shop and office fixtures, turnery.
  • Other: used for guitar backs and sides.

Properties

  • Density: 690kg/m3 at 12% moisture content; about 1.5m3 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 according to 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 impregnates with preservative but penetration of heartwood is negligible using available commercial processes.
  • Seasoning: slow to dry with risk of surface checking; be careful when drying using conventional air and kiln seasoning.
  • Hardness: moderately hard (rated 3 on a 6-class scale) to indent and work with hand tools.
  • Machining: can be abrasive to machine cutters and hand tools due to silica in the wood.
  • Fixing: no difficulty using standard fittings and fastenings.
  • Gluing: can be satisfactorily bonded using standard procedures.
  • Finishing: readily accepts paint, stain and polish.

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; solitary and in short radial multiples, uniformly distributed; vessel lines are distinct on longitudinal surfaces; tyloses are common.
  • Resin canals: visible under a lens mostly as irregular apotracheal bands.
  • Rays: distinct under a lens.

Other features

  • Burning splinter test: match-size splinter burns to charcoal.
  • Figure (pattern): often slightly wavy grain, producing attractive figure on quarter-sawn surfaces.

Research and resources

  • Boland, DJ, Brooker, MIH, Chippendale, GM, Hall, N, Hyland, BPM, Johnston, RD, Kleinig, DA and Turner, JD 2006, Forest trees of Australia, 5th ed., CSIRO Publishing, Collingwood, Australia.
  • Bootle, K 2005, Wood in Australia: Types, properties and uses, 2nd ed., McGraw-Hill, Sydney.
  • Ilic, J 1991, CSIRO atlas of hardwoods, Crawford House Press, Bathurst, Australia.
  • Queensland Government, DAF 2018, Construction timbers in Queensland: Properties and specifications for satisfactory performance of construction timbers in Queensland. Class 1 and Class 10 buildings, Books 1 & 2, Department of Agriculture and Fisheries, Brisbane.
  • Standards Australia, 2000, AS 2082—2000: Timber—Hardwood—Visually stress-graded for structural purposes, Standards Australia International, Strathfield, NSW.