Synoum muelleri, S. glandulosum. Family: Meliaceae.
Northern scentless rosewood (S. muelleri), red sycamore (S. glandulosum).
|Description and natural occurrence|
A medium-sized tree attaining a height of 20 m and a stem diameter of 0.5 m. The trunk is sometimes irregular and angular in cross section but not prominently buttressed. The bark is brown, very scaly, and measures 6 to 12 mm in thickness. It is shed in small, angular pieces.
S. muelleri: North Queensland coastal rainforests from Tully to Atherton Tableland.
S. glandulosum: Coastal rainforests from the south coast of New South Wales to Bundaberg, Queensland.
Colour. Heartwood ranges from red to reddish-brown. Sapwood is sometimes paler in colour but not always distinguishable from the heartwood.
Grain. Relatively close and uniform in texture; predominantly straight. Similar to rose mahogany (Dysoxylum fraseranum) but without its characteristic odour.
Density. 625-675 kg/m3 at 12% moisture content; approximately 1.5 m3 of seasoned sawn timber per tonne.
Strength groups. S. muelleri (S6) unseasoned; (SD6) seasoned. S. glandulosum (S5) unseasoned; (SD6) seasoned (brackets indicate provisional value).
Stress grades. S. muelleri F4, F5, F7, F8, (unseasoned), S. glandulosum F5, F7, F8, F11, (unseasoned), both species F7, F8, F11, F14 (seasoned), when visually stress graded in accordance with AS 2082:2000, Timber - hardwood visually stress-graded for structural purposes.
Joint groups. J3 unseasoned; JD3 seasoned.
Shrinkage to 12% MC. 6.3% (tangential); 3.4% (radial). These values apply to S. glandulosum only.
Unit shrinkage. 0.27% (tangential); 0.18% (radial). These values apply to timber of S. glandulosum reconditioned after seasoning.
Durability above-ground. Class 4 - life expectancy less than 7 years.
Durability in-ground. Class 4 - less than 5 years.
Lyctine susceptibility. Untreated sapwood is 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. Can be satisfactorily dried using conventional air and kiln seasoning methods.
Hardness. Firm (rated 4 on a 6 class scale) in relation to indentation and ease of working with hand tools.
Machining. Machines and turns well to a smooth surface.
Fixing. No difficulty has been experienced with the use of standard fittings and fastenings.
Gluing. Can be satisfactorily bonded using standard procedures.
Finishing. Occasionally, boards cut from certain trees develop beads of oil (oleo resin) on the surface, which stain the wood and prevent the adherence of polish and paint. If the timber is polished, this oiliness causes a dull blotchy bloom to appear and if painted, it causes peeling of the paint film. The only real solution is to store the timber in dressed form for several months and to exclude from finishing uses any boards showing signs of resin exudation.
Construction. Has been used as sawn timber for general house framing, flooring, mouldings and joinery.
Decorative. Furniture, shop and office fixtures, panelling, turnery, carving.
Others. Structural plywood, scaffold planks, wood wool, paper products, particleboard, medium density fibreboard.
Sapwood. Yellow to pink-red.
Heartwood. Red to reddish-brown.
Texture. Medium to fine, straight grained.
Growth rings. Absent.
Vessels. Medium to small in size, invisible without a lens, solitary, with some short radial multiples, uniformly distributed. Vessel lines visible on dressed longitudinal surfaces. Pale coloured vessel deposits common.
Parenchyma. Abundant in numerous fine, short paratracheal and confluent regular bands.
Rays. Fine, invisible without a lens.
Burning splinter test. Produces a grey-white ash filament.
Surface characteristics. Dressed surfaces are greasy to touch.
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.