Cinnamomum (PROSEA Timbers)

Plant Resources of South-East Asia Introduction

List of species

Cinnamomum Schaeffer

Protologue: Bot. exped.: 74 (1760).

Family: Lauraceae

Chromosome number: x= 12; 2n= 24 for all species studied

Trade groups

Camphorwood: lightweight to medium-weight hardwood, e.g. Cinnamomum iners Reinw. ex Blume, C. porrectum (Roxb.) Kosterm., C. sintoc Blume.

Cinnamomum wood is often traded as medang together with other Lauraceae timber from e.g. Alseodaphne, Beilschmiedia, Cryptocarya, Dehaasia, Litsea, Persea and Phoebe.

Vernacular names

• Camphorwood: cinnamon (En)
• Indonesia: medang, huru.

Origin and geographic distribution

Cinnamomum consists of about 250 species (estimates of about 150 species have also been published) occurring in continental Asia, Malesia, Australia, the Pacific, and a few species in Central and South America. Within the Malesian area some 90 species have been recognized.

Uses

The timber is used for decorative work such as interior finish and panelling, for furniture, cabinet making, lining chests, wardrobes, and is suitable for plywood manufacture. The heavier timber is used for medium-heavy construction under cover. The fragrant wood is suitable for making moth-proof chests.

The mucilage of one species (C. iners) has found technical applications, e.g. in the manufacture of mosquito coils, fragrant joss-sticks, plastic products, formica, glue, inner layering of tyres, coating of high-quality paper products, paints and fibre glass.

The major use of several Cinnamomum species is as a spice, like cinnamon, the bark of C. verum J. Presl (synonym: C. zeylanicum Blume), and cassia or cassia vera. The principal sources of cassia bark are C. cassia J. Presl (Chinese cinnamon), C. tamala (Buch.-Ham.) T. Nees & Eberm. (Indian cassia), C. loureirii C. Nees and C. burmannii (C. Nees & T. Nees) Blume (Padang cassia). Cinnamon and cassia are widely used for culinary purposes and flavouring of processed foods. Cinnamon oil is employed in perfumes and as flavouring ingredients in foods and drinks. C. camphora (L.) J. Presl, introduced in South-East Asia from Japan, is an important source of camphor and camphor oil and is used in many industrial products.

The bark, leaves and roots are used medicinally and the bark and fruits are used in local perfumes. The trees are planted as ornamentals along roads and as shade trees.

Production and international trade

Cinnamomum timber is traded in Malaysia in the trade group medang together with the timber of other Lauraceae genera. The total export of medang in 1984 from Peninsular Malaysia to Singapore was 1500 m³with a value of US$ 62 000, the export from Sabah in 1992 was 52 000 m³(about 10% as sawn timber) with a total value of US$ 4.3 million.

In Papua New Guinea, camphorwood is ranked in MEP (Minimum Export Price) group 4, together with other Lauraceae timbers (medang); in 1992, saw logs fetched a minimum price of US$ 43/m³.

Cassia vera is an important export product from Indonesia: in 1989 the export was 12 000 t with a value of US$ 38.2 million.

Properties

Camphorwood is a lightweight to medium-weight hardwood. The heartwood varies in colour from greyish-green to pinkish, reddish or pale brown, sometimes turning to red-brown or walnut-brown on exposure, and is usually not distinctly demarcated from the straw-coloured, pale pink or pale brown sapwood. The density is (350-)370-860 kg/m³at 15% moisture content. The grain is straight to moderately interlocked, texture moderately fine and even. Usually the wood has a persistent camphor-like odour.

At 12% moisture content, the modulus of rupture is 44-93.5 N/mm², modulus of elasticity 7315-12 570 N/mm², compression parallel to grain 28-52 N/mm², compression perpendicular to grain c. 5.5 N/mm², shear 5.5-7.5 N/mm², cleavage 33.5-57.5 N/mm tangential, and Janka side hardness 1580-4390 N.

The rates of shrinkage are small to moderate: from green to 12% moisture content 1.6% radial and 4.8% tangential, from green to oven dry 3.3% radial and 5.7% tangential. The wood generally air dries readily with little or no degrade, but some species have a tendency to warping; wood of C. mercadoi warps badly unless very carefully seasoned. It is recommended to treat the timber with anti-stain chemicals before drying. The wood is stable in use.

The working properties are good. The wood is easy to saw and works well with hand tools and machines, but it is sometimes weak and brittle. It finishes smoothly. The nail-holding properties are good, and the wood takes paint, varnish and lacquer well. However, in Taiwan several species are reported to be corrosive to ferrous metals.

Camphorwood is rated as non-durable to moderately durable when exposed to the weather or in contact with the ground; C. porrectum wood is ranked amongst the more durable woods. The wood of many species is resistant to insect attack, but in Papua New Guinea camphorwood is reported to be susceptible to Lyctus attack. The heartwood is very difficult to treat with preservatives, even when using a pressure treatment.

Camphor is obtained by steam distillation of the heartwood. It is a translucent mass with crystalline fracture. The essential oils contain predominantly eugenol and safrol. A. mercadoi wood extract markedly inhibits the development of two types of cancer.

Description

• Evergreen or deciduous shrubs or small to large trees up to 50 m tall; bole branchless for up to 30 m, up to 125 cm in diameter, buttresses short or absent; bark surface smooth, rarely fissured, lenticellate, grey-brown to reddish-brown, inner bark granular, pale brown to pink or reddish-brown, with a strong aromatic smell; sapwood whitish to pale yellow.
• Leaves usually opposite, subopposite, alternate or arranged spirally, simple and entire, with glandular dots and aromatic when crushed, 3-veined, rarely pinnately veined (C. porrectum); stipules absent.
• Inflorescence consisting of axillary or terminal cymose panicles of clusters or umbellules of flowers.
• Flowers bisexual, rarely unisexual (and then polygamous), trimerous; tepals 6, subequal, united into a tube at base, usually hairy; fertile stamens 9, rarely 6, in 3 whorls, stamens in the outer 2 whorls introrse, in the inner whorl extrorse and with a pair of stalked or sessile glands, anthers 4-celled, rarely 2-celled; ovary superior, sessile, 1-celled, with a single, pendulous, anatropous ovule, style slender, with a discoid or obscurely 3-lobed stigma.
• Fruit a 1-seeded berry, globose or ovoid to cylindrical, the basal part surrounded by the enlarged and indurated perianth tube often carrying persistent perianth lobes; pedicel usually not enlarged.
• Seed without albumen, with a thin testa; cotyledons large, flat, convex and pressed against each other; embryo minute.

Wood anatomy

• Macroscopic characters:

Heartwood yellowish-brown to red-brown, not distinctly demarcated from the paler sapwood. Grain straight to moderately interlocked. Texture moderately fine and even; planed surfaces greasy to the touch; a persistent camphor-like odour present in most species (but reportedly absent in e.g. C. javanicum and C. scortechinii). Growth rings usually present but indistinct; vessels hardly visible to the naked eye or only visible with a hand lens; parenchyma and rays usually not distinct to the naked eye; ripple marks absent.

• Microscopic characters:

Growth rings indistinct to vague, marked by thick-walled and flattened latewood fibres, occasionally also by discontinuous marginal parenchyma bands (e.g. in C. porrectum). Vessels diffuse, 20-50/mm², solitary and in radial multiples of 2-3(-4), rarely in small clusters, angular to round or oval, average tangential diameter 80-170(-200)μm; perforations predominantly simple, but sporadic scalariform plates with few bars occurring in all species; intervessel pits alternate, non-vestured, round to polygonal, 8-12μm; vessel-ray and vessel-parenchyma pits with reduced borders to simple, horizontally elongated (gash-like); helical thickenings and deposits absent; tyloses usually present. Fibres 1130-1580μm long, all non-septate or partly septate in some species (e.g. C. porrectum and C. sintoc), thin-walled to thick-walled, depending on the species, with simple to minutely bordered pits mainly confined to the radial walls. Parenchyma sparse to abundant, vasicentric to weakly aliform; apotracheal parenchyma diffuse and rarely (C. porrectum) additionally in marginal bands of 1-2 cells wide, in 3-6-celled strands. Rays 6-7/mm, 2-3(-5) cells wide, up to 0.7 mm high, heterocellular with 1(-2) rows of square to upright marginal cells. Crystals absent in most species, but minute crystals of various shapes present in ray cells in some species. Silica bodies absent. Secretory (oil or mucilage) cells associated with ray and axial parenchyma.

Species studied: C. iners, C. porrectum, C. sintoc, C. verum.

Growth and development

Cinnamomum trees are reported to grow rapidly. In 24-28-old trial plantations in Java, the mean annual increment was 1.2 cm in diameter and 0.7-1.0 m in height for C. porrectum. C. camphora grows fast under favourable conditions in its natural habitat (e.g. in Japan), and can reach a height of 10 m and a diameter of 15 cm in 10 years.

Flushes of young leaves are often strikingly reddish. The flowers are pollinated by various small insects (e.g. flies and beetles). The fruits are eaten by monkeys, squirrels, bats and birds; the seeds are probably often dispersed by birds.

Other botanical information

Cinnamomum can be distinguished from other Lauraceae genera by the often 3-veined leaves and the enlarged perianth tube at the base of the fruit.

Ecology

Cinnamomum occurs scattered, although sometimes locally abundant, in primary lowland and hill forest or sometimes in montane forest up to 2000(-3000) m altitude. It is usually found in evergreen, but sometimes in semi-evergreen forest on both fertile and poor soils, sometimes in kerangas, swamp or coastal forest.

Propagation and planting

Cinnamomum can be propagated by seed, but the species producing cinnamon, cassia or camphor are also propagated by various methods of vegetative propagation such as air layering, root cuttings, cuttings from root suckers and by division of the root stock.

The number of dry seed per kg is about 6400 for C. iners and 20 000 for C. porrectum. Seeds cannot be stored, as they very rapidly lose their viability; however, seed of C. camphora may be stored for up to 6 months. After depulping, seed should be dried for only a short time and then sown directly afterwards under shade. Viability of fresh seed is about 40% for C. iners, 80% for C. verum and 40-60% for C. camphora.

Stumping of C. iners has been found to be rather successful: 85% of the stumps of 20 cm long and 0.5 cm in diameter developed into healthy plants; 20 cm long stumps of C. sintoc with a diameter of less than 0.5 cm did not survive at all.

Soil requirements depend on the species. C. iners in Sarawak is very tolerant of poor soils and still grows fairly rapidly. C. sintoc, however, planted on poor marl soils in Java does not grow well; the trees reached a mean height of 2 m 9 years after planting. C. sintoc is successfully planted on very permeable soils. In Peninsular Malaysia, C. camphora thrives on poor lateritic soils with good drainage.

Silviculture and management

In Peninsular Malaysia, "medang" includes a very large number of species which do not grow to timber size and which cannot yet be differentiated from those Lauraceae species which do reach timber size. All medang species must therefore be excluded from preferential treatment at present.

A mixed plantation of C. iners and teak (Tectona grandis L.f.) was not satisfactory, as C. iners did not nurse the teak trees to develop a longer clear bole. Seven years after planting the height of C. iners was only 2-3 m.

Cinnamomum trees resprout after fire. The cinnamon and cassia producing species are managed by coppicing; C. camphora in particular has a strong coppicing capacity.

Diseases and pests

In Java, dieback of C. iners was caused by a fungus identified as Aecidium cinnamomi producing black-brown spots on leaves and twigs.

Yield

In the Elmerrillia ovalis (Miq.) Dandy forest in North Sulawesi, the estimated timber volume of C. iners was 4.5-15 m³/ha.

Genetic resources

Cinnamomum seems not to be particularly endangered by genetic erosion, as the trees are not usually subjected to selective logging. However, rarer endemic species may be easily endangered by forest clearings. The species producing cinnamon and cassia barks are widely cultivated and therefore their genetic diversity is well maintained.

Prospects

The demand for the spices cinnamon and cassia has always been satisfactory, and the prospects are still promising as the competition with synthetic alternatives does not noticeably affect the trade. The prospects for the essential oils seem to be slightly less bright as there are many alternatives. Little attention has been paid to the production of camphorwood, as plantation trees are merely valued for cinnamon, cinnamon oil or cassia. However, the wood is suitable for special decorative purposes, and there may be scope for multipurpose plantations including timber production. More research is needed on silvicultural management of camphorwood plantations.

Literature

• 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. 16-19.
• Browne, F.G., 1955. Forest trees of Sarawak and Brunei and their products. Government Printing Office, Kuching, Sarawak. pp. 211-216.
• Burgess, P.F., 1966. Timbers of Sabah. Sabah Forest Records No 6. Forest Department, Sabah. pp. 330-340.
• de Guzman, E., Umali, R.M. & Sotalbo, E.D., 1986. Guide to the Philippine flora and fauna. Vol. 3: dipterocarps, non-dipterocarps. Natural Resources Management Center, Ministry of Natural Resources and University of the Philippines, Manila. pp. 103-105.
• Eddowes, P.J., 1977. Commercial timbers of Papua New Guinea. Their properties and uses. Office of Forests, Department of Primary Industry, Port Moresby. pp. 46-47.
• Kochummen, K.M., 1989. Lauraceae. In: Ng, F.S.P. (Editor): Tree flora of Malaya. A manual for foresters. 2nd edition. Vol. 4. Malayan Forest Records No 26. Forest Research Institute Malaysia. Longman Malaysia SDN. Berhad, Petaling Jaya. pp. 98-178.
• Kostermans, A.J.G.H., 1986. A monograph of the genus Cinnamomum Schaeff. (Lauraceae), part I. Ginkgoana No 6. Academia Scientific Book Inc., Tokyo. 171 pp.
• Martawijaya, A., Kartasujana, I., Kadir, K. & Prawira, S.A., 1986. Indonesian wood atlas. Vol. 1. Forest Products Research and Development Centre, Bogor. pp. 68-73.
• Meniado, J.A., Tamolang, F.N., Lopez, F.R., America, W.M. & Alonzo, D.S., 1975. Wood identification handbook for Philippine timbers. Vol. 1. Government Printing Office, Manila. pp. 139-140.
• Research Institute of Wood Industry, 1988. Identification, properties and uses of some Southeast Asian woods. Chinese Academy of Forestry, Beijing and International Tropical Timber Organization, Yokohama. p. 72.