Anthocephalus (PROSEA)

Plant Resources of South-East Asia
Introduction

Protologue: Mém. Rubiac.: 157 (1830).

Family: Rubiaceae

Chromosome number: x= unknown; A. chinensis:n= 22

Trade groups

Kadam: lightweight hardwood, Anthocephalus chinensis (Lamk) A. Rich. ex Walp. and A. macrophyllus (Roxb.) Havil.

Vernacular names

Kadam

cadamba, common bur-flower tree (En)
Brunei: bangkal, kaatoan bangkal
Indonesia: jabon (Java), laran (Kalimantan), emajang (Sumatra)
Malaysia: kelempayan (Peninsular), laran (Peninsular, Sabah), selimpoh (Sarawak)
Papua New Guinea: labula
Philippines: kaatoan bangkal (Pilipino, general)
Burma: mau-lettan-she, maukadon, yemau
Cambodia: thkoow
Laos: koo-somz, sako
Thailand: krathum (central, northern), krathum-bok (Bangkok), taku (Sukhothai, Chanthaburi, Nakhon Si Thamarrat)
Vietnam: cây gáo, cà tom, gáo trắng

Origin and geographic distribution

Anthocephalus consists of 2 species and occurs naturally from Sri Lanka, India, Nepal and Bangladesh eastward through Malesia to New Guinea. A. chinensis covers the complete area of distribution of the genus. It has been planted as an ornamental and plantation tree and has been successfully introduced in South Africa, Puerto Rico, Surinam, Taiwan and other tropical and subtropical countries.

Uses

The wood, being highly perishable in contact with the ground, cannot be used in outdoor conditions and is moderately durable under cover. It can be used for light construction work, beams and rafters, boxes, tea-chests, packing cases, shuttering, ceiling boards, toys, wooden shoes, bobbins, yokes, carvings, matches, chopsticks and pencils. It is also suitable for dug-outs or canoes and less expensive furniture if properly seasoned. The wood is applied as both face and core veneer in plywood and is suitable for the manufacture of particle board, cement-bonded board and hardboard. Its most important usage is for the manufacture of low- and medium-quality paper. The pulp is sometimes mixed with other, generally long-fibred, material. The tree is also suitable as an ornamental and shade tree for other crops and is used for reforestation and in agroforestry.

An extract of the leaves serves as a gargle and the fresh leaves are used as fodder for cattle or sometimes as plates and serviettes. The inflorescences and the fruits are said to be edible. The dried bark is used to relieve fever and as a tonic. A yellow dye can be obtained from the bark of the roots.

Production and international trade

Although kadam is planted in many places in the tropics, production data are scarce. Most of the wood is used locally. Export data on the wood are mixed with data from other, not well-defined lightweight woods. In 1987 the export of kadam round logs from Sabah was 67 000 m³ with a value of US$ 4.1 million, and in 1992 32 000 m³ of logs and 9000 m³ of sawn timber with a total value of US$ 3.9 million. In 1988 the average price of one cubic metre of wood was about US$ 60. In Papua New Guinea kadam wood is ranked in MEP (Minimum Export Price) group 3, which fetches moderate prices (minimum export price of logs about US$ 50/m³). In Thailand only very small amounts are traded in the domestic market (about 300 m³ in 1988).

Kadam is becoming one of the most frequently planted trees in the tropics. In South-East Asia alone, several hundred thousand ha are estimated to be planted. In the future, kadam might compete with the African obeche/samba/wawa (Triplochiton scleroxylon K. Schumann) wood.

Properties

Kadam is a lightweight hardwood. The heartwood is white with a yellow tinge darkening to creamy yellow on exposure, and not clearly differentiated from the sapwood. The density is 290-465(-560) kg/m³at 15% moisture content. The grain of the wood is generally straight, texture fine and even.

At 15% moisture content, the wood of A. chinensis has the following mechanical properties: modulus of rupture 50-73 N/mm², modulus of elasticity (5000-)6700-9300 N/mm², compression parallel to grain (23-)28-44 N/mm², shear 5-8 N/mm², cleavage c. 35 N/mm radial and 54 N/mm tangential, Janka side hardness 1950-2625 N and Janka end hardness 3000-4000 N.

The rates of shrinkage are low to moderate, from green to 15% moisture content about 0.8% radial and 2.1% tangential, from green to 12% moisture content 0.8% radial and 3.1% tangential, and from green to oven dry 2.5% radial and 5.9% tangential. The timber air dries fairly rapidly with little or no degrade, but care is needed to prevent blue stain. Boards 2.5 cm thick take about 1.5 month to air dry from green to 15% moisture content. For kiln drying from green to 20% moisture content a temperature of 57-76.5°C and corresponding relative humidity of 80% to 40% is recommended.

Kadam is easy to work with hand and machine tools, it cuts cleanly and gives a very good surface, although tearing out may give slight problems. Test results of the machining properties indicate that the wood can be shaped, mortised and sanded with good results, and planed, bored and turned with moderate results. The nailing properties are excellent, and the wood glues well. It peels readily at a cutting angle of 92°, producing good veneer 1.5 mm thick. It produces sulphate pulp with sufficient paper-making quality. Kraft pulping gives a yield of 48.5% and pulp of satisfactory brightness and performance as a handsheet.

The wood is regarded as non-durable. Graveyard tests in Indonesia show an average life in contact with the ground of less than 1.5 years. The wood is susceptible to wood rotting fungi and blue stain. It is also susceptible to termite, Anobium and marine borer attack. It is, however, very easy to treat using either the open tank system or the vacuum-pressure system. It can easily be impregnated with synthetic resins to increase density and compressive strength.

The wood of A. macrophyllus is much like that of A. chinensis, but it is believed to be somewhat stronger. It is rose-coloured.

The wood of A. chinensis contains 47-52% cellulose, 25.5% lignin, 16-24% pentosan, 0.8-1.9% ash, and very little or no silica. The solubility is 4.7% in alcohol-benzene, 1.6% in cold water, 3.1% in hot water and 18.4% in a 1% NaOH solution. The energy value of the wood is 19 800 kJ/kg. The charcoal is odourless and does not smoke or spark, but the low yield in comparison with other species makes it uneconomic.

Description

Medium-sized to large deciduous trees up to 45 m tall; bole straight and cylindrical, often branchless for more than 25 m, up to 100(-160) cm in diameter but generally less, sometimes with small buttresses up to 2 m high and extending up to 60 cm from the trunk; outer bark very light and smooth when young, grey to grey-brown with shallow fissures when old, sometimes with small ridges, often cracked and rather coarsely flaky; crown typically umbrella-shaped, small; branches horizontally spreading and drooping at the tip, arranged in tiers, scars of fallen branches visible for several years on young stems.
Leaves opposite, simple, more or less sessile to petiolate, ovate to elliptical, 15-50 cm × 8-25 cm, in young fertilized trees sometimes much larger, subcordate at base, acuminate at apex; stipules interpetiolar, narrowly triangular, deciduous. Inflorescence consisting of terminal, solitary, globose heads without bracteoles.
Flowers subsessile on a glabrous receptacle, bisexual, actinomorphic, 5-merous; calyx tube funnel-shaped, with narrow lobes pubescent outside; corolla gamopetalous, saucer-shaped with a narrow tube, the narrow lobes imbricate in bud; stamens 5, inserted on the corolla tube, filaments short, anthers basifixed; ovary inferior, 2-locular, sometimes 4-locular in the upper part, style exserted, stigma spindle-shaped.
Fruitlets numerous, somewhat fleshy, the upper part containing 4 hollow or solid structures.
Seed somewhat trigonal or irregular-shaped, not winged.
Seedling with epigeal germination; cotyledons sessile, herbaceous, acute, green; leaves opposite.

Wood anatomy

Macroscopic characters

Heartwood white with a faint yellowish cast, ageing to creamy white or light yellowish-grey, indistinct from the sapwood.
Grain straight.
Texture fine to moderately fine and even; wood without characteristic odour or taste.
Growth rings moderately distinct but not conspicuous, visible to the naked eye, usually wide (2-13 mm), delimitated by faint pink bands (on transverse section); largest vessels clearly visible to the naked eye, vessels forming conspicuous, nearly straight lines; parenchyma and rays not distinct to the naked eye; ripple marks absent.

Microscopic characters

Growth rings not conspicuous.
Vessels diffuse, 4-12/mm², solitary and in diagonal and/or radial rows of 2-4, rarely in clusters, medium-sized, average tangential diameter 100-200μm; perforation plates simple; intervessel pits alternate, round to polygonal, vestured, maximum diameter 6-8μm; vessel-ray pits similar to intervessel pits; gum-like deposits and tyloses absent.
Fibres (600-)1300-2200μm long, 34-40μm in diameter, non-septate, non-libriform to semi-libriform in the outer portion of the growth ring, walls in the earlywood 2-6μm thick, in the latewood 6-10μm, with comparatively abundant, orbicular to broadly oval bordered pits, confined to the radial walls.
Paratracheal parenchyma extremely sparse, restricted to occasional cells and sometimes absent; apotracheal parenchyma diffuse or diffuse-in-aggregates or forming short uniseriate lines.
Rays 12-17/mm, of 2 distinct sizes; narrow rays 1(-2)-seriate and consisting wholly of upright cells, 6-8 cells and c. 550μm high, somewhat more numerous than broad rays; broad rays 2-4-seriate and composed of upright, square and procumbent cells, c. 25 cells and c. 800μm high (Kribs type heterogeneous I).
Crystals, silica and intercellular canals absent; starch deposits sometimes present in the outer growth rings.

Species studied: A. chinensis.

Growth and development

Seeds are dispersed by wind or rain, floods and rivers. Full sunlight is required for germination. Saplings commonly form pure stands on flood-damaged river banks and surface-stripped sites along logging roads. Young seedlings do not withstand strong competition of weeds and grasses and they will only develop into trees if not overgrown by surrounding vegetation or strangled by lianas. At the age of 4 years trees may start flowering. In Indonesia flowering occurs from April to August, sometimes from March to November.

In natural stands, root anastomosis has often been observed. Cutting of some of the trees in a clump results in the production of some wood stumps that keep growing without producing leaves, comparable to "ash trays" in young thinned Douglas-fir stands. Kadam grows rapidly. Annual increment in height up to 3 m/year, in diameter up to 7 cm/year is reported for the first 6-8 years, slowing down to about 2 m and 3 cm respectively until the 20th year. Thereafter growth is much slower. The annual volume increment is 10-20(-26) m³/ha. At the age of 10-15 years trees can be felled. Under optimal management (including fertilization) this rotation may be much shorter, e.g. in the STTC (Sumatra Tobacco Trade Company) plantations in North Sumatra (Indonesia) where the rotations are 4 years for match production. A. macrophyllus is said to grow faster, but extremely few experimental data are available. In West Java A. macrophyllus trees in a 10.5-year-old stand had an average height of 22 m and an average diameter of 40.5 cm.

Other botanical information

The genus Anthocephalus belongs to the tribe Naucleeae within which it has a rather isolated position as the sole genus of the subtribe Anthocephalinae. It seems to be most closely allied to the genera of the subtribe Naucleinae but differs from them by the mode of placentation. There is controversy about the correct name of Anthocephalus chinensis and even about the legitimacy of the generic name Anthocephalus. The problem focuses on disagreement about the proper type specimen for the species originally described by Lamarck. Here, the solution offering nomenclatorial stability and which has recently gained more support is adopted. The other option means rejecting the name Anthocephalus as a synonym for Breonia from Madagascar and using the newly created generic name, Neolamarckia, to incorporate the species formerly assigned to Anthocephalus.

Ecology

Kadam is a typical pioneer and is very common in secondary forest. Sometimes large individuals can be found in primary rain forests. The most important condition for growth is light. Kadam does not tolerate shade. In its natural habitat, maximum temperature varies from 32-43°C in the shade and minimum temperature from 3-15.5°C. Kadam is sensitive to frost. The average annual rainfall ranges from 1500-5000 mm or more. Kadam may, however, also occur locally on much drier sites with as little as 200 mm annual rainfall (e.g. in parts of central South Sulawesi). Near the equator it is found from sea-level up to 1000 m altitude. It grows on a variety of soils but is more abundant and dominant on well-aerated fertile soils. Kadam does not grow well on leached soils, even when their physical conditions are good. It occurs on river banks and in the transitional zone between swampy, permanently flooded areas and the drier loams, in areas which are periodically flooded.

Propagation and planting

Propagation is possible by natural regeneration from seed, by nursery-grown seedlings, stumps and stem cuttings. Special techniques are required to extract the minute seeds from the fleshy multiple fruit. In the Philippines, fresh fruits are rubbed and macerated in water to extract the seeds; in Indonesia, fruits are dried before the seeds are rubbed out. The weight of a million air-dry seeds is about 38-56 g. The germination rate of fresh seeds is variable, but generally low (about 25%). When stored cool in airtight boxes for 2.5 months, a much higher germination rate can be obtained (up to 95%). Properly stored seeds can remain viable for about 2 years.

In the nursery, seeds are mixed with fine sand (1 : 10) and sown in seed-beds. Water is applied by irrigation or overhead as a very fine mist. In the open, seed-beds should be protected against heavy rains. Germination starts 12-21 days after sowing. A mild fungicidal spray may be used to prevent damping-off.

Seedlings 8-12 weeks old are transplanted to nursery beds or plastic bags, preferably in growing medium enriched with organic matter. When 6-7 months old and 30 cm tall, they are transplanted into the field. Sometimes, under good care seedlings are planted out at 10-15 cm. Kadam can be planted bare-rooted, without significant loss of growth and with high survival percentages. Planting saplings of about 1 cm diameter that have been topped gives satisfactory results. Planting distance in the field is 3-4 m × 3-4 m. In Indonesia and the Philippines promising results have been obtained with rows of Leucaena leucocephala (Lamk) de Wit between the lines. In Borneo kadam plantations have been intercropped with upland rice. Kadam has also proved to be an excellent shade tree for dipterocarp line planting.

Silviculture and management

If enough seed-producing trees are available, natural regeneration from seed can be effected by clearing the soil at the time of seed ripening. In East Kalimantan, a plantation has been maintained for several years since 1938 using this system. Plantations established from nursery seedlings seldom show the same favourable growth rate as natural regeneration, for reasons still unknown but probably related to local site conditions. There is much difference in performance between trees from different seed sources as well as between plantations with a different topography. Notable differences in performace related to site conditions have been observed, even within a single plantation.

Applying about 15 g urea per plant in a ring around the seedling results in much faster growth. The trees provide only light shade. After planting, the soil around the young trees needs to be kept free from competing vegetation, especially from climbers and plants causing shade. Thinning is very easy owing to the beautifully straight stems without defects and the very regular small crowns. It should be done early and frequently. The rotation period depends upon soil characteristics. In the Philippines, economic rotations applied in plantations were 5 years for pulp wood and 7 years for the combination of pulp wood and sawn timber. A match factory in Sumatra is growing kadam on a 4-year rotation.

Diseases and pests

No serious diseases or pests occur. The fungus Gloeosporium anthocephali may cause partial or complete defoliation and dieback. Often, leaves are eaten by a variety of insects, whereas seedlings are eaten by game. Trees with severely perforated leaves are very common, but usually recover well. Pests reported in the Philippines include the leafminer bagworm Pyralis sp., the borer Pterodepleryx sp. and hornworms.

In Costa Rica, small soil-inhabiting ants eat the seeds from the seed-beds. Keeping a small ditch filled with water around the seed-bed or placing seedlings in trays on tables overcomes the problem. Seedlings should be placed in well-ventilated conditions to prevent damping-off disease.

Harvesting

For pulpwood and matches, harvesting can start 4-5 years after sowing. For wood production, felling of trees can start from the age of 10 years when, depending upon soil conditions, trees have a diameter of 50 cm.

The wood is readily attacked by fungi causing, for example, blue stain. Therefore, the wood has to be worked up soon after cutting, or it should be treated within 48 hours or be submerged in water.

Yield

In a 30-year rotation in Indonesia, the stand attained an average height of 38 m and average diameter of 65 cm, producing 350 m³/ha in the final cut. Total production including thinnings amounted to 23 m³/ha per year. Those data refer to all wood, including branches with a diameter of 7 cm and more. A tree of 50 cm diameter yields 2.5-3 m³ wood.

Genetic resources

The preservation of the genetic diversity of kadam seems guaranteed, as the trees are widespread and common, and are planted on a fairly large scale.

Prospects

Because of its very fast growth, its ability to grow on a variety of soils, the absence of serious diseases and pests, and its favourable silvicultural characteristics, kadam is expected to become increasingly important in the near future, when supplies for plywood from natural forests are expected to decrease. The selection of and/or breeding a less site-sensitive provenance should receive priority.

Literature

Cacanindin, D.C., 1986. Tree volume, yield and economic rotation of kaatoan bangkal (Anthocephalus chinensis (Lam.) Rich. ex Walp.) plantations in Nasipit Lumber Company, Tungao, Butuan City. Part 2: Yield prediction models. Sylvatrop 11: 23-34.
Fox, J.E.D., 1971. Anthocephalus chinensis, the laram tree of Sabah. Economic Botany 25: 221-233.
Grijpma, P., 1967. Anthocephalus cadamba, a versatile, fast growing industrial tree species for the tropics. Dasonomia Interamericano 17: 321-329; Turrialba 3(1): 321-329.
Harris, I.M. & Soendiono, J., 1951. Normal volume table for Anthocephalus cadamba Miq. Pengumuman No 69, Lembaga Penelitian Kehutanan, Bogor. 12 pp.
Haslett, A.N., 1986. Properties and uses of the timbers of western Samoa. Plantation-grown exotic hardwoods. Ministry of Foreign Affairs, Wellington. pp. 12-13.
Lamprecht, H., 1989. Silviculture in the tropics. Tropical forest ecosystems and their tree species-possibilities and methods for their long-term utilization. Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH, Eschborn. pp. 225-226.
Martawijaya, A., Kartasujana, I., Mandang, Y.I., Prawira, S.A. & Kadir, K., 1989. Atlas kayu Indonesia [Indonesian wood atlas]. Vol. 2. Forest Products Research and Development Centre, Bogor. pp. 55-59.
Meniado, J.A., Lopez, F.R. & Tamolang, F.N., 1979. Wood quality and utilization of Philippine plantation species IV. Kaatoan bangkal (Anthocephalus chinensis (Lamk.) Rich. ex Walp.). Philippine Lumberman 25(8): 18-19.
Ridsdale, C.E., 1978. A revision of the tribe Naucleeae s.s. Blumea 24: 333-334.
Sudarmo, M.K., 1957. Preliminary yield-table of Anthocephalus cadamba Miq. (djabon). Pengumuman No 59. Lembaga Penelitian Kehutanan, Bogor. 13 pp.

Selection of species

Authors

W.T.M. Smits (general part),
J.W. Hildebrand (general part),
W.G. Keating (properties),
J.M. Fundter (wood anatomy),
M.S.M. Sosef (selection of species)