Coronavirus (COVID-19) update: Complete our 2-minute survey and tell us what information you need to help your business during COVID-19. Find assistance and support for coronavirus affected businesses and industries

Yellow walnut

Scientific name

Beilschmiedia bancroftii. Family: Lauraceae

Other names

Canary ash; yellow nut

Description

  • Well-shaped, medium-sized tree
  • Grows 25–30m high.
  • Stem is 1.0–1.5m diameter.
  • Trunk is sometimes crooked or irregular and slightly buttressed for 2–5m from the ground line.
  • Bark can be up to 25mm thick, brown and partly rough with small pustules.
  • When cut, the middle layer of bark is reddish brown and has an odour like sugar cane.

Occurrence

  • Occurs in North Queensland rainforests around the:
    • Johnstone and Russell Rivers
    • Evelyn and Daintree Rivers
    • Bellenden-Kerr Range
    • Atherton Tableland.
  • Timber has very limited commercial availability.

Appearance

Colour

  • Heartwood is pale to bright lemon yellow.
  • Sapwood is generally paler but sometimes difficult to distinguish from the heartwood, especially since it can occupy up to 50% of the stem radius.

Grain

  • Moderately course, straight grained with little or no figure (pattern).

Uses

  • Decorative: plywood, furniture, joinery, turnery, carving, panelling.
  • Other: sawn timber in general house framing, flooring, linings, mouldings and joinery.

Properties

  • Density: 640kg/m3 at 12% moisture content; about 1.6m3 of seasoned sawn timber per tonne.
  • Strength groups: S4 unseasoned, SD5 seasoned.
  • Stress grades: F7, F8, F11, F14 (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: J3 unseasoned, JD3 seasoned.
  • Shrinkage to 12% MC: 3.8% (tangential), 2.1% (radial).
  • Unit shrinkage: 0.27% (tangential), 0.17% (radial)—these values apply to timber reconditioned after seasoning.
  • Durability above-ground: Class 4 (life expectancy 0–7 years).
  • Durability in-ground: Class 4 (life expectancy 0–5 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 unsatisfactory using available commercial processes.
  • Seasoning: dries satisfactorily using conventional air and kiln seasoning.
  • Hardness: firm (rated 4 on a 6-class scale) to indent and work with hand tools.
  • Machining: abrasive to machine cutters and tools due to silica in the wood.
  • Fixing: no difficulty using standard fittings and fastenings.
  • Gluing: bonds satisfactorily using standard procedures.
  • Finishing: readily accepts stain, polish and paint.

Identification features

General characteristics

  • Sapwood: pale yellow to nearly white.
  • Heartwood: pale to bright lemon yellow, often with dark streaks towards the heart.
  • Texture: moderately course and uniform, grain is generally straight.

Wood structure

  • Growth rings: absent.
  • Vessels: solitary or in radial groups of 2–5 cells with occasional clusters; medium and evenly distributed; obvious vessel lines on dressed longitudinal surfaces.
  • Parenchyma (soft tissue): numerous, irregularly spaced, apotracheal bands—prominent as they are lighter than the background.
  • Rays: fine and distinct but less prominent than parenchyma.

Other features

  • Burning splinter test: wood burns with some smoke to a charcoal tip and grey ash filament.
  • Figure: dressed back-sawn surfaces may occasionally show figure (pattern) due to earlywood/latewood cells forming rings.

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.