5091

5(3): Timber trees; Lesser-known timbers

Ceratopetalum J.E. Smith

Spec. bot. New Holland 1: 9, t. 3 (1793).

CUNONIACEAE

x = unknown; C. gummiferum J.E. Smith: 2n = 32

Coachwood (En, trade name). Blood-in-the-bark, satin sycamore (En). Papua New Guinea: Papua New Guinea coachwood (En).

Ceratopetalum comprises 6 species distributed in eastern Australia and New Guinea. C. succirubrum C.T. White (synonym: C. tetrapterum Mattf.) is the only Malesian species occurring in New Guinea and north-eastern Australia (Queensland).

C. succirubrum is widely used in furniture and cabinet work. It also finds many applications in house building where it serves for decorative wall panelling, interior trim, flooring, fine finish, light framing and shop and office fittings. It is also applied for boat building, joinery, mouldings, dowels, turnery, carving, rifle butts, brush backs, tool handles (non-impact) and for parts of various machinery. C. succirubrum is frequently used to make fruit cases and is claimed to be suitable for musical instruments. It is excellent for the production of plywood and is suitable for both core stock and face veneer.

In 1996 Papua New Guinea exported 108 m³ of C. succirubrum logs at an average free-on-board (FOB) price of US$ 92/m³. In Australia Ceratopetalum is of considerable commercial importance on a local scale.

C. succirubrum yields a medium-weight hardwood with a density of 600-825 kg/m³ at 15% moisture content. Heartwood pale to dark pinkish-brown, not clearly differentiated from the straw or pale brown sapwood; grain straight to slightly interlocked; texture fine; wood with characteristic figure on tangential surface due to the parenchyma bands; wood with caramel-like odour. Growth rings indistinct; vessels moderately small, solitary and in radial multiples of 2-4, rarely in clusters, occasional tyloses and white deposits present; parenchyma abundant, apotracheal in narrow or rarely wide, regularly or irregularly spaced bands; rays fine; ripple marks absent.
Shrinkage upon seasoning is low to moderate and the wood requires careful seasoning as it is liable to twist in drying. The wood is moderately strong, tough and non-durable. The sapwood is non-susceptible to Lyctus. The wood is fairly resistant to pressure treatment.
The mean fibre length is 1.34-1.54 mm.
See also the tables on microscopic wood anatomy and wood properties.

An evergreen, small to medium-sized tree up to 35 m tall; bole straight, cylindrical, branchless for up to 27 m, up to 100 cm in diameter, with small buttresses; bark surface smooth but flaky, brownish-grey and mottled, hoop-marked, inner bark reddish-brown, with little, thick dark red exudate; crown very light. Leaves decussate, (2-)3-foliolate; leaflets entire to serrate, prominently veined; stipules connate, enclosing the terminal bud, caducous. Inflorescence a terminal or axillary, corymbose panicle but dichasial in the apical branches. Flowers 4(-5)-merous; sepals valvate; petals absent; stamens 8(-10); disk annular; ovary semi-inferior, 2-locular with 4 ovules in each cell, styles 2, divergent. Fruit a dry, indehiscent, 2-seeded capsule with radiating persistent and enlarged sepals turning red. Seedling with orbicular cotyledons; hypocotyl glabrous; young leaves serrate.
In Queensland C. succirubrum flowers in November and December, fruits ripen in January and February. The fruits are dispersed by wind.

C. succirubrum is found in primary rain forest at 400-1200 m altitude where it favours fertile soils; it is especially abundant on granite substrates. In Papua New Guinea it also occurs near sea-level, in mixed gallery forest on the Oriomo plateau and in low hill forest dominated by dipterocarps in Kiunga, Western Province.

In Australia Ceratopetalum can easily be grown from seed, but its growth is slow.

It is difficult to assess the risk of genetic erosion of C. succirubrum as on the one hand it is of local commercial importance and on the other hand it is locally abundant.

The commercial interest in C. succirubrum in Papua New Guinea will remain relatively important, but supplies are very limited.

[124]Bolza, E. & Kloot, N.H., 1963. The mechanical properties of 174 Australian timbers. Technological Paper No 25. Division of Forest Products, CSIRO, Melbourne. 112 pp.
[128]Bootle, K.R., 1983. Wood in Australia. Types, properties and uses. McGraw-Hill Book Company, Sydney. 443 pp.
[215]Dadswell, H.E. & Eckersley, A.M., 1938. The wood structure of some Australian Cunoniaceae with methods for their identification. Technical Paper No 27. Division of Forest Products, Council for Scientific and Industrial Research, Melbourne. 23 pp.
[269]Dickison, W.C., 1980. Comparative wood anatomy and evolution of the Cunoniaceae. Allertonia 2: 281-321.
[270]Dickison, W.C., 1984. Fruits and seeds of the Cunoniaceae. Journal of the Arnold Arboretum 65: 149-190.
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[304]Eddowes, P.J., 1995-1997. The forests and timbers of Papua New Guinea. (unpublished data).
[356]Francis, W.D., 1970. Australian rain-forest trees. Australian Government Publication Service, Canberra. 468 pp.
[446]Hoogland, R.D., 1960. Studies in the Cunoniaceae I. The genera Ceratopetalum, Gillbeea, Aistopetalum and Calycomis. Australian Journal of Botany 8: 318-341.
[463]Hyland, B.P.M. & Whiffin, T., 1993. Australian tropical rain forest trees: an interactive identification system. CSIRO Publishing, Melbourne. 2 Volumes + Atlas.
[464]Ilic, J., 1990. The CSIRO macro key for hardwood identification. CSIRO, Highett. 125 pp.
[470]Ingle, H.D. & Dadswell, H.E., 1956. The anatomy of timbers of the south-west Pacific area IV. Cunoniaceae, Davidsoniaceae and Eucryphiaceae. Australian Journal of Botany 4: 125-151.
[568]Kingston, R.S.T. & Risdon, C.J.E., 1961. Shrinkage and density of Australian and other South-West Pacific woods. Technological Paper No 13. Division of Forest Products, CSIRO, Melbourne. 65 pp.
[861]Oey Djoen Seng, 1951. De soortelijke gewichten van Indonesische houtsoorten en hun betekenis voor de praktijk [Specific gravity of Indonesian woods and its significance for practical use]. Rapport No 46. Bosbouwproefstation, Bogor. 183 pp.
[1204]White, C.T., 1936. Contributions to the Queensland flora No 5. Proceedings of the Royal Society of Queensland 47: 51-84.
[1232]Wisse, J.H., 1965. Volumegewichten van een aantal houtmonsters uit West Nieuw Guinea [Specific gravity of some wood samples from West New Guinea]. Afdeling Bosexploitatie en Boshuishoudkunde, Landbouwhogeschool, Wageningen. 23 pp.

W.C. Dickison

Dickison, W.C., 1998. Ceratopetalum J.E. Smith. In: Sosef, M.S.M., Hong, L.T. and Prawirohatmodjo, S. (Editors): Plant Resources of South-East Asia No 5(3): Timber trees; Lesser-known timbers. PROSEA Foundation, Bogor, Indonesia. Database record: prota4u.org/prosea