Scaphium (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Scaphium Schott & Endl.

Protologue: Melet. Bot: 33 (1832).

Family: Sterculiaceae

Chromosome number: x= unknown

Trade groups

Kembang semangkok: lightweight to medium-heavy hardwood, e.g. Scaphium macropodum (Miq.) Beumée ex K. Heyne.

Vernacular names

Kembang semangkok

• Indonesia: kapas-kapasan (general), merpayang (Sumatra)
• Burma: shaw taung-thinbow
• Thailand: phungthalai (central), samrong (south-eastern).

Origin and geographic distribution

The genus Scaphium, consisting of 8 species, is distributed in Burma, Cambodia, Thailand, Peninsular Malaysia, Singapore, Sumatra, Bangka, and Borneo. S. macropodum is the most widespread species, covering almost the entire distribution area of the genus. Several species from Sumatra and Borneo are rare or have been collected only once; they are not treated here.

Uses

The timber is used particularly for veneer and plywood, but also for interior finishing (e.g. panelling, stairs) and furniture. In the furniture industry in Europe it is sometimes used as a substitute for oak (from Quercus spp.), and in India as a substitute for timber from Salmalia spp. It is also suitable for match splints, boxes and crates.

The fruits are used medicinally. When the seed is soaked in water, a sour mucilaginous substance is produced which is eaten as a jelly and used as a remedy against lung diseases, colds, diarrhoea, and kidney complaints. It may also be used to prepare a beverage or sorbet by adding sugar, syrup or fruit juice. The bitter basal part should then be removed. The fibrous bark is sometimes applied as walling for local houses.

Production and international trade

Large, pure consignments of the timber are difficult to obtain since the trees occur scattered. Sawn kembang semangkok timber is probably traded together with other timbers as mixed light or medium-heavy hardwood. In 1983 the total export of sawlogs of kembang semangkok from Peninsular Malaysia was 2500 m³ with a value of US$ 110 000. The destinations were particularly East Asian countries, e.g. South Korea, Hong Kong and Taiwan. Japan imports kembang semangkok timber especially from Sabah and Sarawak. The export of round logs from Sabah in 1987 was 59 000 m³ with a value of US$ 4.2 million (US$ 71.5/m³); in 1992 the export was 20 000 m³ of logs and 3000 m³of sawn timber with a total value of US$ 2.1 million.

Dried seeds are exported for medicine to India and China under the name "pungtalai", and to Java under the name of "buah tampayang".

Properties

Kembang semangkok is a light to medium-weight and soft to moderately hard wood. It is buff-coloured, yellowish-brown to greyish-brown. The density is 515-760(-800) kg/m³ at 15% moisture content. The grain is straight or shallowly interlocked, texture moderately coarse to coarse and uneven.

At 17% moisture content the modulus of rupture is 92-105 N/mm², modulus of elasticity 14 000-17 000 N/mm², compression parallel to grain 47-60 N/mm², shear 9-12 N/mm², cleavage 34 N/mm radial and 52 N/mm tangential, and Janka side hardness 4940-5210 N.

The rates of shrinkage of kembang semangkok are small, from green to 12% moisture content 1.2% radial and 3.0% tangential, from green to oven dry 2.5% radial and 4.2% tangential. Drying is easy and rapid. The timber is liable to small end checks. It takes about 9 weeks to air dry 15 mm thick boards, and about 17 weeks for 50 mm thick boards. The recommended kiln schedule in Malaysia is H.

The timber is not easy to saw because of its high silica content (2.1-2.6%), which causes rapid blunting of saw-teeth. Hard-metal saws are necessary, and stellite-tipped teeth are recommended. Kembang semangkok finishes and turns to a smooth surface, and nailing and screwing are easy. Gluing and staining present no problems. Kembang semangkok gives a decorative veneer. It can be peeled easily to various thicknesses of veneer without any form of pretreatment. Veneers are smooth and tight, and can be glued easily to obtain good plywood.

The timber is not durable. It is perishable in contact with the ground or when exposed to the weather. Graveyard tests in Indonesia showed an average service life in contact with the ground of only 0.9 years, and laboratory tests showed a poor resistance to wood-rotting fungi. The sapwood is susceptible to blue stain fungus and to attack by powder-post beetles and drywood termites. Kembang semangkok is easy to treat with preservatives; using the open tank method and an equal mixture of creosote and diesel, an absorption of 190-320 kg/m³ is achieved.

The pericarp of fruits of S. scaphigerum contains about 15% galactose and 25% pentoses (mainly arabinose). Air-dried fruits of S. macropodum contain 4.5% protein, 24% pentosans and 40% carbohydrates. The seeds can be stored for many years without losing their medicinal properties and without changing their taste.

Description

• Medium-sized to large, deciduous, monoecious trees up to 45 m tall with bole up to 80 cm in diameter, usually having large and thick buttresses; outer bark fissured in patches or flaky in small, rectangular pieces, greyish-brown to brown, inner bark fibrous, pale yellowish-brown, with thin but conspicuous red outer layer; crown usually irregularly hemispherical and somewhat diffuse; twigs stout, with prominent leaf scars.
• Leaves arranged spirally, in mature trees simple and entire, long-stalked with petiole thickened near top, leathery, those of saplings simple, lobed or palmately pinnate; stipules present but caducous.
• Inflorescences axillary, paniculate, near tips of branches, scurfy pubescent and many-flowered.
• Flowers unisexual, with male and female flowers borne on separate inflorescences, small and pale green, globose and sessile in bud; calyx 4-6-lobed, corolla absent; male flowers with staminal column bearing 8 anthers in a globose woolly head; female flowers with slender androgynophore bearing a conical ovary with 2-5 erect or recurved styles terminated by conspicuous disk-like stigmas, and 8-10 sterile anthers around base of ovary.
• Fruit a large follicle, dehiscing early after fertilization, boat-shaped and membraneous, reticulately veined, with a single basal seed.
• Seed hairy or glabrous, outer seed-coat swelling on moistening to produce a mass of clear mucilage.
• Seedling with epigeal germination, phanerocotylar, with strongly enlarging hypocotyl and foliaceous cotyledons; all seedling leaves arranged spirally.

Wood anatomy

• Macroscopic characters:

• Demarcation between heartwood and sapwood not distinct; sapwood yellowish-white to light yellowish-grey, heartwood somewhat darker.
• Grain straight to shallowly interlocked.
• Texture rather coarse.
• Growth rings indistinct or distinct; rays distinct to the naked eye, showing silvery grain on radial surface.
• Ripple marks occasionally visible to the naked eye.

• Microscopic characters:

• Growth rings, if distinct, marked by parenchyma bands at the ring boundary.
• Vessels diffuse, 2-3.5/mm², solitary and in radial multiples of 2-4, in almost similar proportion, usually 190-270 μm in maximum tangential diameter; perforations simple; intervessel pits alternate, 6-7 μm, often with coalescent apertures; vessel-ray and vessel parenchyma pits almost similar to intervessel pits but half-bordered.
• Fibres 0.8-1.4 mm long, very thin- to thin-walled (walls c. 2 μm thick); pits with minute borders, numerous, confined to the radial walls.
• Parenchyma winged-aliform, sometimes confluent, apotracheally diffuse-in-aggregates or in interrupted fine lines, often marginal; usually in 4-celled strands.
• Rays 5-7/mm, of two distinct sizes, low, 1-2-seriates and high, 6-17-seriates, heterocellular, with one row of square marginal cells (Kribs type heterogeneous III), upright or square cells sheathing the periphery of multiseriate part of the rays, but they are not typical sheath cells; maximum height 3800-4800 μm.
• Silica bodies present in axial and ray parenchyma cells, the amount depending on the sample.
• All elements, except the broad rays, storied.

Species studied: S. macropodum .

Growth and development

The taproot and hypocotyl emerge from the free pole of the fruit, after which a resting stage occurs. Then the hypocotyl becomes erect, the primary seedling leaves ("paracotyledons") spread, and a second resting stage follows. The leaves of seedlings are entire or 3-lobed; those of saplings palmately pinnate (S. longipetiolatum ), 5-7-lobed (S. linearicarpum, S. macropodum) or simple (S. longiflorum, S. scaphigerum), and always distinctly larger than the entire leaves of mature trees, and with long petioles. Trees flower when they are leafless and before the new leaves develop. The flowers are insect-pollinated; they attract bees, flies, butterflies and beetles.

Ecology

Usually kembang semangkok occurs scattered in primary lowland forest, most commonly in mixed dipterocarp forest in humid tropical conditions and generally in areas with a short dry season. S. macropodum and S. longipetiolatum are often found on ridges and well-drained undulating land up to 1200 m altitude. S. longiflorum grows scattered in swampy forest, whereas S. scaphigerum occurs in places with a pronounced dry season.

Propagation and planting

Regeneration under natural conditions is usually abundant; seedlings are often numerous in the forest. However, the few tests with seeds in nurseries showed a low percentage of germination. The mortality of planted preconditioned seedlings is low (about 10%), and the seedlings are fairly drought-resistant. Growth is, however, generally rather slow, and seedlings are rarely planted.

Silviculture and management

Kembang semangkok has proven to be suitable for enrichment planting in hill dipterocarp forest in Peninsular Malaysia.

Genetic resources

Scaphium trees occur scattered in primary forest, and several species are rare. This makes the species liable to genetic erosion in areas with large-scale logging operations.

Prospects

Kembang semangkok was seldom used until the 1970s because the timber is not durable, it has a high silica content and is abrasive, and because large and pure consignments were difficult to obtain. It is now much more in demand as a general-utility timber resembling light red meranti, but it is particularly popular for veneer. There is a lack of information on almost all silvicultural aspects, and of experience with propagation techniques and planting.

Literature

• Ashton, P.S., 1988. Manual of the non-dipterocarp trees of Sarawak. Vol. 2. Sarawak Branch for Forest Department, Sarawak. pp. 404-408.
• Browne, F.G., 1955. Forest trees of Sarawak and Brunei and their products. Government Printing Office, Kuching. pp. 329-330.
• Burgess, P.F., 1966. Timbers of Sabah. Sabah Forest Records No 6. Forest Department, Sabah, Sandakan. p. 467.
• Cockburn, P.F., 1976. Trees of Sabah. Vol. 1. Forest Department, Sabah, Kuching. pp. 239-243.
• Desch, H.E., 1954. Manual of Malayan timbers. Vol. 2. Malayan Forest Records No 15. Malaya Publishing House Ltd., Singapore. pp. 580-581.
• de Vogel, E.F., 1980. Seedlings of dicotyledons. PUDOC, Wageningen. pp. 439-441.
• Kochummen, K.M., 1972. Sterculiaceae. In: Whitmore, T.C. (Editor): Tree flora of Malaya. Vol. 2. Malayan Forest Records No 26. Longman Malaysia SDN Berhad, Kuala Lumpur. pp. 353-376.
• Kostermans, A.J.G.H., 1953. The genera Scaphium Schott & Endl. and Hildegardia Schott & Endl. (Sterculiaceae). Journal of Scientific Research Indonesia 2(1): 13-21.
• Lim, S.C., 1987. Malaysian timbers - kembang semangkok. Timber Trade Leaflet No 105. Malaysian Timber Industry Board, Forest Research Institute Malaysia. 7 pp.
• Malaysian Timber Industry Board, 1986. 100 Malaysian timbers. Kuala Lumpur. pp. 142-143.

Selection of species

• Scaphium borneensis
• Scaphium linearicarpum
• Scaphium longiflorum
• Scaphium longipetiolatum
• Scaphium macropodum
• Scaphium scaphigerum

Authors

• A.J.G.H. Kostermans (general part),
• J.E. Polman (properties),
• S. Sudo (wood anatomy),
• R.H.M.J. Lemmens (selection of species)