Canarium (PROSEA Timbers)
- Protologue: Amoen. Acad. 4: 143 (1759).
- Family: Burseraceae
- Chromosome number: x= unknown; C. ovatum: 2n= 46, 2n= 48 for 2 species from Indo-China and China (C. album Raeuschel ex DC. and C. pimela König)
Kedondong: lightweight to medium-weight hardwood, e.g. Canarium hirsutum Willd., C. indicum L., C. littorale Blume, C. luzonicum (Blume) A. Gray.
Kedondong is the standard trade name for all timber of the family Burseraceae, hence in addition to Canarium timber also including the timber of Dacryodes, Garuga, Protium, Santiria, Scutinanthe and Triomma.
- Brunei: upi
- Indonesia: kenari, kerantai
- Malaysia: kerantai (Sabah), upi, seladah (Sarawak)
- Papua New Guinea: canarium, galip
- Philippines: pili, piling-liitan, pagsahingin (Filipino)
- Thailand: makoem
- Vietnam: trám.
Origin and geographic distribution
Canarium consists of about 80 species and is distributed in the Old World tropics, from tropical Africa to tropical Asia, northern Australia and the Pacific. The main centre of diversity lies in the Malesian area where most species occur in the moister parts, hence in Peninsular Malaysia, Sumatra and Borneo in the west and New Guinea in the east.
The timber, being part of the kedondong trade group, is used for house building, light or temporary constructions, doors, window frames, flooring, mouldings, interior finish, boxes, crates, furniture, joinery, prahus and canoes, veneer and plywood. It is locally preferred for tool handles and also used as firewood. The wood cannot be used for outdoor construction because it is non-durable and difficult to treat with preservatives. Paddles have been manufactured from the buttresses.
The fruits of some species are boiled and eaten; the pulp is edible. The fruit pulp also contains an oil, which is occasionally used for cooking and lighting. Several species have edible seeds. Occasionally, an edible oil is extracted from the kernels, which may be used as a substitute for coconut oil. In the Solomon Islands, the oil is used in skin and hair care products. The kernel, known as pilinut (or ngali in Melanesia), is used commercially for bakery products and as a flavouring for ice-cream. It can also be eaten roasted or boiled and forms an important element of rural cooking in Melanesia. The hard and thick shell enclosing the seeds makes an excellent fuel for cooking. When polished and varnished, the stone is an attractive ornament. The bark of a few species is known to yield tannin. Resin, known as "Manila elemi" in the Philippines, is used locally as a varnish, for caulking boats, for torches, as a kind of glue for fixing metal in wood (e.g. for knives) and in local medicine; it is also exported for use in medicinal ointments, and occasionally in varnishes. In China, it is used to manufacture transparent paper used for making window panes. A decoction of the roots is also used for medicinal purposes. As well as being cultivated for its fruits and seeds, Canarium trees are also planted in wind-breaks and their symmetrical branching makes them attractive avenue and shade trees.
Production and international trade
Instead of being traded separately, Canarium timber is usually mixed with the timber of other Burseraceae genera and sold as kedondong. In 1983, 16 350 m3of kedondong sawlogs were exported from Peninsular Malaysia (69% to Singapore, 19% to South Korea and 12% to Hong Kong) with a total value of US$ 675 000, and in 1984 9500 m3(99% to Singapore and 1% to Japan) with a value of US$ 395 000 (US$ 42/m3). The export of round logs from Sabah was only 1170 m3with a value of US$ 75 000 (US$ 64/m3) in 1987, but in 1992 the export of kedondong timber from Sabah was much more: 15 000 m3(17% as sawn timber, 83% as logs) with a total value of US$ 1.3 million (US$ 170/m3for sawn timber and US$ 69/m3for logs). Canarium timber is often imported into Japan in consignments of "mixed light hardwood". Japan imports Canarium timber from Sabah, Sarawak, Papua New Guinea and the Solomon Islands.
The Philippines is the only country producing and processing pilinuts in commercial quantities. In 1983-1987, the annual volume was 2925 t of dried stones from an estimated area of 2700 ha. The most important pilinut-producing region is Bicol. The rural production of pilinuts in Melanesia is probably high.
Canarium wood is lightweight to medium-weight and moderately soft to moderately hard. The heartwood is nearly white or buff-coloured to pale pinkish-brown or reddish-brown, sometimes with yellowish streaks. The sapwood is paler and often not clearlydemarcated from the heartwood. The density is (360-)390-780(-815) kg/m3at 15% moisture content. The grain is rather straight to shallowly interlocked, texture fine to moderately coarse and even. Planed surfaces are lustrous and the wood has no distinctive odour or taste.
At 12% moisture content, the modulus of rupture is 77.5-109 N/mm2, modulus of elasticity 7370-14 630 N/mm2, compression parallel to grain 38-60.5 N/mm2, compression perpendicular to grain 8-9.5 N/mm2, shear 13-14 N/mm2, cleavage c. 60 N/mm radial, Janka side hardness 3275-5205 N and Janka end hardness 5160-5670 N.
The rates of shrinkage are moderately low to fairly high: for C. littorale wood from green to 15% moisture content 2.4% radial and 4.1% tangential, for C. asperum wood from green to oven dry 5.1% radial and 6.6% tangential. The timber dries rather slowly but without serious defects, although slight bowing, springing and splitting may occur. Boards 15 mm thick take about 3.5 months to air dry from green condition to 15% moisture content, and boards 40 mm thick take about 4 months. Kiln-drying schedule J is recommended in Malaysia; boards 25 mm thick take about 6 days to kiln dry from 50% to 10% moisture content. During drying, the wood is susceptible to mould and blue staining.
The wood is easy to moderately difficult to saw and plane, depending on the density and silica content. Lighter-weight and non-siliceous wood saws easily and the planed surfaces are smooth on the radial and tangential surfaces. Heavier and siliceous wood (silica contents up to 1.7% have been reported) is much harder to saw and the blunting effect on saw teeth is severe; planed surfaces are smooth and non-lustrous. Usually the wood bores, turns, nails and glues well, and it is easy to rotary peel and produces a good tight veneer. Brittle heart may cause some problems during peeling. Kedondong is likely to be suitable for fibreboard and particle board.
The wood is non-durable in exposed conditions or in contact with the ground. Graveyard tests in Malaysia showed an average life in contact with the ground of 1.2 years for C. littorale wood. The wood is readily attacked by fungi and termites, and blue staining can be a serious problem. The sapwood is very susceptible to powder-post beetle attack. The heartwood is highly resistant to preservative treatment, because of the occurrence of tyloses (an absorption of 32 kg/m3has been achieved using an open tank method), but the sapwood is permeable.
Wood of C. littorale contains 69% holocellulose, 42%α-cellulose, 25.5% lignin, 14% pentosan and 0.4% ash. The solubility is 1.2% in alcohol-benzene, 2.7% in hot water and 15.6% in a 1% NaOH solution.
- Dioecious, evergreen, medium-sized to fairly large, sometimes large trees up to 35(-60) m tall, rarely shrubs; bole branchless for up to 25(-45) m, up to 120(-200) cm in diameter, buttresses present; bark surface smooth to scaly or dippled, often greyish, inner bark sometimes laminated, pinkish or reddish-brown, with strong resinous smell and clear sticky or oily exudate; pith of twigs usually containing vascular strands.
- Leaves arranged spirally, imparipinnate, with (1-)3-17(-27) opposite and often toothed leaflets; base of petiole and of petiolules often swollen; stipules usually present, entire to fimbriate.
- Inflorescence terminal or sometimes axillary, paniculate or sometimes reduced to a raceme or a spike.
- Flowers actinomorphic, 3-merous, functionally unisexual but vestiges of the opposite sex present; calyx cupular with deltoid lobes, nearly always densely hairy inside; petals free, usually imbricate, creamy white, with inflexed tips; stamens 6, or rarely 3, free to entirely connate; disk intrastaminal, 6-lobed, often pilose; ovary superior, 3-celled, each cell with 2 axillary ovules, stigma sessile or short-stalked.
- Fruit an oblong drupe, seated on a persistent enlarged calyx, hairy or glabrous, ripening blue-black, glaucous at first, very wrinkled when dry; endocarp stony (pyrene), with 1 or 2 cells slightly to nearly entirely reduced.
- Seed with palmatifid to 3-foliolate and variously folded cotyledons.
- Seedling with epigeal germination; first 2 leaves simple and opposite, entire or toothed, subsequent leaves alternate and eventually arranged spirally and imparipinnate.
- Macroscopic characters:
Heartwood buff-coloured, pale pinkish-brown or reddish-brown, often not clearly distinct from the nearly white or greyish-white sapwood. Grain rather straight to shallowly interlocked. Texture fine to moderately coarse. Growth rings generally indistinct or absent, sometimes delimited by dark fibrous bands; vessels visible to the naked eye, tyloses infrequent; parenchyma not visible with a hand lens; rays not visible to the naked eye; ripple marks absent.
- Microscopic characters:
Growth rings indistinct or absent, sometimes delimited by dark fibrous bands. Vessels diffuse, 8-13/mm2, in short radial multiples, mostly 120-200μm in diameter (up to 280μm in C. indicum); perforation plates simple; intervessel pits alternate, non-vestured, circular or oval, 8-10μm (occasionally up to 12μm in C. asperum); vessel-ray pits simple with much reduced borders, enlarged, horizontally to vertically elongated or round; tyloses occasional to absent. Fibres 0.8-1.4 mm long, septate, thin-walled to thick-walled, with simple to minutely bordered pits mainly confined to the radial walls. Axial parenchyma absent or extremely rare to scanty and vasicentric, in strands with 8 or more cells. Rays usually 3-7/mm, mostly 300-600μm high, typicallyheterocellular with one row of upright and/or square marginal cells (sometimes with two rows), mostly 2-3(-4) cells wide; storied structure absent. Prismatic crystals in upright cells and occasionally procumbent cells in C. acutifolium, C. asperum, C. luzonicum and C. ovatum, in chambered upright cells and chambered axial parenchyma cells and occasionally in fibres in C. indicum and absent from C. hirsutum; one crystal per cell or chamber. Silica bodies absent or present in procumbent and upright ray cells and fibres in C. asperum and C. hirsutum. Radial canals absent in C. acutifolium, C. asperum and C. hirsutum, but present in C. indicum, C. luzonicum and C. ovatum; rays containing canals enlarged locally around the canal, producing distinct fusiform rays.
Species studied: C. acutifolium, C. asperum, C. hirsutum, C. indicum, C. luzonicum, C. ovatum.
Growth and development
An average annual diameter increment of a small C. asperum tree in secondary forest of 1.9 cm has been recorded. In plantation trials of C. indicum in the Solomon Islands the growth rates averaged 2.8 m/year in height and 3 cm/year in diameter. Juvenile trees of C. ovatum produce lateral shoots late. They may grow to a height of 2 m or more in about 3-4 years before branching.
The trees flower mainly in the dry season and fruit during the wet season, although many species do not have definite flowering or fruiting seasons. Flowering and fruiting of C. vulgare occurs throughout the year in West Java, as does the flowering of C. decumanum; fruits are ripe in February-March and October. Pollination is probably effected by insects. The fruits are dispersed by fruit-eating pigeons and monkeys, and are occasionally eaten and dispersed by bats.
Other botanical information
Canarium is closely related to the genera Dacryodes, Haplolobus and Santiria. It is characterized by the often stipulate leaves, the vascular strands being usually present in the twigs, and especially by the peculiar fruits with a thick-walled, bony, and 1-3-seeded stone, the pyrene. Material without fruits may be confused with the other 3 related genera.
The genus Canarium is subdivided into 3 subgenera: subgenus Canarium, subgenus Canariellum (Engl.) Leenh., and subgenus Africanarium (Leenh.) Leenh. The first is the most widespread, occurring from Africa to the Pacific. The second is restricted to eastern Queensland, New Caledonia and adjacent islands. The third is monotypic and confined to western Africa.
Species of Canarium are mainly canopy trees of primary lowland evergreen rain forest, although some species are found up to 1800 m altitude. They also occur in monsoon or more open forest, or in secondary forest, where some species may be locally abundant. The individuals usually occur scattered but C. vulgare may grow gregariously in rather dry rain forest.
Propagation and planting
Canarium can be propagated by seed and seedlings may be prepared as stumps before planting. Vegetative methods of propagation are practised for the fruit species, e.g. budding and grafting techniques are used for C. ovatum. One kg contains 200-1350 seeds of C. ovatum and there are about 145 dry stones (each stone containing 1-2 seeds) of C. vulgare per kg. The fruits can be collected from the ground and the pulp needs to be removed to make germination possible. Germination can be hastened by nicking the end of the stone, slightly cracking it and soaking in cold or hot water. Air-dry seed can be stored without temperature control for several months up to 1.5 years, as recorded for C. vulgare, without losing its viability. C. littorale stones showed 25-100% germination in 30-171 days in different germination trials, C. megalanthum stones 95% germination in 17-21 days, and C. pseudosumatranum stones 90% germination in 34-88 days. C. vulgare stones have 85% viability. Seeds are sown under shade. A plantation trial in Indonesia with stumps was not very successful because of serious attacks by termites. Only stumps of 40 cm long and with a diameter of 1-2.5 cm of C. littorale had a survival rate of 75% after being planted out. The African species C. schweinfurthii Engl. was planted in Java as a trial and developed well. For fruit production, approximately 120 C. indicum trees are planted per ha (spacing about 9 m) in the Solomon Islands, and C. ovatum is planted in the Philippines at a spacing of 12-15 m (45-70 trees/ha).
Silviculture and management
As Canarium trees generally grow scattered and the fruits are often collected for their stones, natural regeneration is scarce.
Diseases and pests
Anthracnose of young seedlings has been observed in C. ovatum, but this is easily controlled by fungicides.
The usually tall buttresses may hinder harvesting of the logs. Trees of C. luzonicum may be tapped for resin on alternate days. The flow of resin diminishes towards the end of the dry season.
In a plot of 50 ha of lowland forest in Peninsular Malaysia 4 Canarium species were present and in total 29 trees were over 40 cm in diameter. This means that much less than 1 tree over 40 cm in diameter per ha was present. In three different forest complexes around Samarinda, East Kalimantan, the yield of kedondong was 4.6 m3/ha, 2.6 m3/ha and 2.1 m3/ha, respectively.
Mature C. indicum trees yield at least 100 kg/year of fruits when open grown and under plantation conditions they can be expected to yield 7700 kg/ha of fruits annually (the kernels account for about 15% of the total weight). The productivity of C. ovatum trees varies considerably. Theaverage yield of resin from a single mature tree of C. luzonicum is about 45 kg.
Handling after harvest
Timber should be treated with anti-stain chemicals immediately after sawing. Kedondong logs float and may be transported by river.
After collecting the fruits, the pulp and the stone wall are removed and the seed is dried in the sun.
Canarium trees are common constituents of lowland and hill rain forest. The genetic resources will not be depleted easily as the timber has not been commercially important to date.
As Canarium trees are dioecious, they are cross-pollinated. This results in great variation among seedlings.
The prospects for Canarium seem to be more towards the production of fruits than of timber. The oil extracted from kernels of C. indicum is already being promoted as a product from the natural rain forest in the Solomon Islands. In Papua New Guinea, there is also interest in developing this industry. Pilinuts (from C. ovatum in the Philippines) have the potential to become a major export product. Plantations from which both timber and pilinuts can be harvested in a sustainable way might have good prospects. More research is needed on silviculture and propagation.
- Ahmad Shakri Mat Seman, 1983. Malaysian timbers - kedondong. Malaysian Forest Service Trade Leaflet No 73. Malaysian Timber Industry Board, Kuala Lumpur. 9 pp.
- All Nippon Checkers Corporation, 1989. Illustrated commercial foreign woods in Japan. Tokyo. p. 29.
- Bolza, E. & Kloot, N.H., 1966. The mechanical properties of 81 New Guinea timbers. Division of Forest Products Technological Paper No 41. Commonwealth Scientific and Industrial Research Organization, Melbourne. pp. 12-15.
- Burgess, P.F., 1966. Timbers of Sabah. Sabah Forest Records No 6. Forest Department, Sabah. pp. 60-70.
- Coronel, R.E., 1991. Canarium ovatum Engl. In: Verheij, E.W.M. & Coronel, R.E. (Editors): Plant Resources of South-East Asia No 2. Edible fruits and nuts. Pudoc, Wageningen. pp. 105-108.
- Kochummen, K.M., 1972. Burseraceae. In: Whitmore, T.C. (Editor): Tree flora of Malaya. A manual for foresters. Vol. 1. Forest Research Institute Malaysia. Longman Malaysia SDN. Berhad, Kuala Lumpur. pp. 121-155.
- Leenhouts, P.W., 1959. Revision of the Burseraceae of the Malaysian area in a wider sense Xa. Canarium Stickm. Blumea 9: 275-647.
- Leenhouts, P.W., Kalkman, C. & Lam, H.J., 1956. Burseraceae. In: van Steenis, C.G.G.J. (Editor): Flora Malesiana. Ser. 1, Vol. 5. Noordhoff-Kolff N.V., Djakarta. pp. 209-296.
- Ng, F.S.P., 1991. Manual of forest fruits, seeds and seedlings. Malayan Forest Record No 34. Vol. 1. Forest Research Institute Malaysia, Kepong, Kuala Lumpur. pp. 36-37, 178-181.
- Research Institute of Wood Industry, 1988. Identification, properties and uses of some Southeast Asian woods. Chinese Academy of Forestry, Wan Shou Shan, Beijing & International Tropical Timber Organization, Yokohama. p. 20.
- K.M. Kochummen (general part, selection of species),
- R.B. Miller (properties, wood anatomy),
- M.S.M. Sosef (selection of species)
Selection of species
- Canarium acutifolium
- Canarium apertum
- Canarium asperum
- Canarium australianum
- Canarium balsamiferum
- Canarium decumanum
- Canarium denticulatum
- Canarium dichotomum
- Canarium euryphyllum
- Canarium grandifolium
- Canarium hirsutum
- Canarium indicum
- Canarium kaniense
- Canarium littorale
- Canarium luzonicum
- Canarium maluense
- Canarium megalanthum
- Canarium odontophyllum
- Canarium oleosum
- Canarium ovatum
- Canarium patentinervium
- Canarium pilosum
- Canarium pseudodecumanum
- Canarium pseudopatentinervium
- Canarium pseudosumatranum
- Canarium rigidum
- Canarium salomonense
- Canarium sumatranum
- Canarium sylvestre
- Canarium vrieseanum
- Canarium vulgare