Erima
Scientific name
Octomeles sumatrana. Family: Etrameleaceae
Other names
Ilimo (PNG); binuang (Philippines, Sarawak); benuang (Indonesia); fote; rara (Solomon Islands)
Description
- Grows to 60m high and 1.5m diameter.
- Trees are of good form, and often heavily buttressed.
- Bark is grey-white to grey-brown with shallow fissures.
Occurrence
- Occurs on rich, alluvial soils along rivers in:
- Sabah
- Sumatra
- Papua New Guinea
- Philippines
- Solomon Islands.
- Major markets are Japan and Hong Kong; however, it’s sometimes imported into Australia.
Appearance
Colour
- Heartwood is yellow-brown, occasionally with a purplish tinge.
- Sapwood is somewhat paler but not always clearly defined.
Grain
- Interlocking common, forms striped figure (pattern) on quarter-sawn stock.
Uses
- Construction: concrete formwork, plywood.
- Decorative: joinery, furniture.
- Others: packing cases, coffins, matchboxes, canoes, treated shingles.
Properties
- Density: 365kg/m3 at 12% moisture content; about 2.7m3 of seasoned sawn timber per tonne.
- Strength groups: S<7 unseasoned, SD8 seasoned.
- Stress grades: non-structural (unseasoned); F4, F5, F7, F8 (seasoned), when visually stress-graded according to AS 2082—2000: Timber—Hardwood—visually stress-graded for structural purposes.
- Joint groups: J6 unseasoned, JD6 seasoned.
- Shrinkage to 12% MC: 4.5% (tangential), 0.13% (radial).
- Unit shrinkage: 0.21% (tangential), 0.13% (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: sapwood is susceptible to lyctid borer attack.
- Termite resistance: not resistant.
- Preservation: sapwood readily impregnates with preservative; penetration of heartwood is unsatisfactory using available commercial processes.
- Seasoning: be careful to minimise degrade by distortion and checking.
- Hardness: very soft (rated 6 on a 6-class scale) to indent and work with hand tools.
- Machining: be careful due to softness; keep cutting edges sharp to avoid woolliness; generally easy to work.
- Fixing: poor rating for holding screws and nails.
- Gluing: satisfactorily bonds using standard procedures.
- Finishing: readily accepts paint, stain and polish; a good polish will give a silky, satin finish.
Identification features
General characteristics
- Sapwood: white to grey-yellow with little distinction from heartwood.
- Heartwood: light yellowish brown; darkens on exposure.
- Texture: medium, open and uniform; grain often interlocked; moderate lustre on dressed radial surfaces.
Wood structure
- Vessels: solitary and radial pairs; diffuse uniform distribution; medium size, visible to the unaided eye; vessel lines are common but not distinctive.
- Parenchyma (soft tissue): not visible with hand lens.
- Rays: moderately fine; distinct as flecks on cut radial surfaces.
Other features
- Burning splinter test: match-size splinter burns to grey ash.
Research and resources
- 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
- Last reviewed: 12 Dec 2018
- Last updated: 12 Dec 2018