3493

5(1): Timber trees; Major commercial timbers

Endospermum Benth.

Fl. Hongk.: 304 (1861).

EUPHORBIACEAE

x = unknown

Trade groups Sesendok: lightweight hardwood, e.g. Endospermum diadenum (Miq.) Airy Shaw, Endospermum moluccanum (Teijsm. & Binnend.) Kurz, Endospermum peltatum Merr.

Sesendok: cheesewood, white milkwood (En). Brunei: terbulan. Indonesia: kayu labu (general). Malaysia: membulan (Peninsular), sendok (Sabah), terbulan (Sarawak). Papua New Guinea: basswood. Philippines: gubas (general). Thailand: taphong (Trat), lokhao (Trang), famo (Surat Thani).

Endospermum consists of 13 species and is widely distributed from Assam (India) throughout mainland South-East Asia and China towards the Malesian archipelago where it occurs in Peninsular Malaysia, Sumatra, Borneo, the Philippines, northern Sulawesi, the Moluccas and New Guinea, and further east towards Fiji and south to northern Queensland. Almost all (12) species occur within the Malesian area. The 3 most widespread ones are Endospermum diadenum, Endospermum moluccanum and Endospermum peltatum.

Sesendok can be used for a variety of purposes where lightweight, comparatively soft and light-coloured hardwood is required. The wood is non-durable when used in contact with the ground, hence all applications should be under cover. The wood is favoured for match boxes and splints and recommended for chopsticks, popsicle sticks, medical sticks (spatula), ice-cream spoons, toothpicks, carvings and handicraft. It is also suited for pattern making, drawing boards, pencil slats, blockboard, trays, furniture parts, picture frames, plywood chests, packing cases and crates, and buoys and floats. Sesendok also supplies suitable material for toys and indoor laminated wood, panelling and moulding. It is favoured for soles and clogs. When treated, the wood can be used for roofing shakes and shingles. Sesendok is in general not suitable for plywood manufacture because of extensive splitting. Its long fibres make it ideal for pulp and paper production as well as fibreboard production. Spiral shavings of the wood of Endospermum peltatum are used as core material in the manufacture of a panel locally known in the Philippines as 'placarol' because of their resistance to compression perpendicular to the direction of the spiral. Whole trunks are sometimes used as masts for local vessels. Several species are used quite extensively for reforestation, especially in Peninsular Malaysia and the Philippines. Sesendok can be used for reclamation of denuded areas.
The bark and leaves have purgative properties; young leaves are slightly purgative but a decoction of old ones can be a strong laxative. Young leaves of some species are sometimes eaten as a vegetable. Seeds have also been reported to be edible. There are reports (unverified) that the thin roots of Endospermum moluccanum have been used as an antidote against arrow poison.

Significant volumes of sesendok logs are exported from Papua New Guinea and the Solomon Islands. Small amounts of sesendok timber on the world market originate from Malaysia (Sabah), Thailand, Indonesia (Sumatra), the Philippines and Fiji. Few export figures are available. In 1978 Sabah exported approximately 1000 m³ of sesendok logs with a value of US$ 68 000, and in 1992 525 m³ (80% as sawn timber) with a value of US$ 57 000. In 1980 approximately 2000-3000 t of sesendok logs per month were required by the match factories in Peninsular Malaysia. In Papua New Guinea sesendok is classified in the MEP (Minimum Export Price) trade group 3 and fetched a minimum export price for saw logs of US$ 50/m³ in 1992. Japan is the main importer of sesendok timber.

Sesendok is a lightweight, comparatively soft and weak wood, resembling that of pulai (Alstonia spp.). The heartwood is yellowish-white to bright yellow, with a greenish tinge when freshly cut, weathering to straw-coloured, not distinctly demarcated from the sapwood. The density is 300-650 kg/m³ at 12% moisture content. The grain of the wood is straight, interlocked or wavy, texture moderately coarse to coarse but even. The surfaces are lustrous, lacking figure.
At 12% moisture content, the modulus of rupture is 57-79 N/mm², modulus of elasticity 7900-10 700 N/mm², compression parallel to grain 36-46 N/mm², compression perpendicular to grain 4-6.5 N/mm², shear 5-12 N/mm², cleavage c. 31 N/mm tangential, Janka side hardness 1600-1825 N Janka end hardness c. 2670 N.
The rates of shrinkage are low to moderate, from green to 15% moisture content c. 1.2% radial and 1.3% tangential, from green to 12% moisture content 1.2-2.1% radial and 2.1-4.0% tangential, and from green to oven dry 1.5-3.0% radial and 3.1%-5.0% tangential. The wood air dries and kiln dries rapidly and without serious degrade, but care should be taken to prevent blue stain, to which the wood is very susceptible. Slight checking may occur during drying. Boards of 15 mm thick take about 2 months to air dry, boards of 40 mm thick about 3 months. In Malaysia kiln schedule J is recommended. Boards with a thickness of 25 mm take approximately 5 days to kiln dry. The timber should be chemically treated or given high temperature treatment to prevent stain and insect attack. After drying, the wood is stable in service.
Sesendok is easy to saw by hand and machine tools, producing smooth surfaces but these may become woolly due to the occasional presence of tension wood. Usually the surface can be planed to a smooth and lustrous finish. Sesendok does not dull sawteeth and edges because the wood is non-siliceous. Boring and turning is easy but fibrous surfaces must be corrected occasionally by sanding. Gluing, painting, screwing and nailing cause no problems. Sesendok has good peeling properties; it peels easily producing good-quality veneer without pretreatment. The gluing properties of the veneer are good, but sesendok is not recommended for the production of plywood, as the veneer may check badly during drying operations.
Sesendok is not durable when used outdoors or in contact with the ground. Tests in Malaysia showed an average service life in contact with the ground of 1 year. The wood is very susceptible to blue stain, termite, pinhole borer and marine borer attack and, when sawn, to longicorn beetle attack. It is, however, easy to treat with preservatives. Using the open tank system and an equal mixture of creosote and diesel fuel, an average absorption of over 320 kg/m³ can be achieved.

Medium-sized to large, dioecious or rarely monoecious, unarmed trees of up to 40(-50) m tall; bole stout, columnar, up to 80(-150) cm in diameter, occasionally buttressed; bark surface smooth but becoming rugose to scaly, hooped, inner bark exuding a watery or coloured sap; crown monopodial, at first pagoda-like or conical, later dome-shaped; branches curving steep upwards, with pith or hollow. Leaves arranged spirally, petioled, simple; leaf peltate or non-peltate, herbaceous to coriaceous, margin entire, sometimes revolute, usually palmately, rarely pinnately veined, with an indumentum of simple or stellate hairs, often with glands at the base and/or in the forks of the lateral veins beneath and/or along the margin above; primary and secondary veins stout, extending to near the margin, looped and joined, tertiary veins fine, perpendicular to the larger ones; petiole generally constricted at one or both ends, leaving large, conspicuous scars; stipules small, narrowly triangular, hairy. Inflorescence axillary, thyrsoid, usually branched but sometimes simple, hairy; bracts and bracteoles small, ovate to deltoid, concave, brownish, hairy. Flowers subsessile to distinctly pedicellate, unisexual or occasionally bisexual, actinomorphic, apetalous; calyx gamosepalous, campanulate, 3-6-lobed, pubescent outside, glabrous inside; male flower with 5-12 stamens arranged spirally on an androphore and with peltate, (3-)4-celled, elliptical anthers dehiscing by a longitudinal slit; female flower with a more or less globose, 1-7-celled, hairy ovary with a single ovule per cell and a sessile, discoid, lobed stigma, rudimentary androecium absent; bisexual flower with an indistinctly lobed calyx and the stamens either at the base of the ovary or arranged spirally on a very short androgynophore, otherwise like the male and female flowers. Fruit more or less drupaceous, indehiscent, with a persistent stigma; exocarp thin to rather thick and fleshy, endocarp thin and woody, fibrous. Seed without caruncle; testa hard, reticulately ribbed, black; radicle triangular, acute. Seedling with epigeal germination; cotyledons leafy; hypocotyl elongated; leaves arranged spirally.

- Macroscopic characters:
Sapwood pale, white to creamy yellow, sometimes with a slight greenish hue, turning to light yellow-brown or straw-coloured, not demarcated from the heartwood. Grain straight to shallowly interlocked, slightly wavy or spiral. Texture coarse but even; wood fissile and with some lustre. Growth rings usually indistinct, sometimes evident due to darker layers of denser wood; vessels medium to large, conspicuously open, discernible to the naked eye, infrequently blocked with tyloses; parenchyma abundant, narrow bands regularly spaced, visible to the naked eye; rays fine, barely discernible to the naked eye as individual rays, inconspicuous on the radial surface.
- Microscopic characters:
Growth rings, if present, evident due to differences in fibre wall thickness on either side of the growth ring boundary. Vessels diffuse, 1-1.5/mm², solitary and in radial multiples of 2-3(-4), rarely in clusters, mostly oval, average tangential diameter c. (200-)250 µm; perforations simple; intervessel pits alternate, round to polygonal, pit border diameter 12-16 µm; vessel-ray pits with reduced borders to almost simple, mostly rounded, sometimes irregular in shape, c. 28 µm; tyloses sparse. Fibres (1.2-)1.6-2.1 mm long, non-septate, thin-walled, moderately thick-walled in latewood zones, with minutely bordered to simple pits mainly in radial walls. Parenchyma usually abundant, apotracheal, in narrow more or less continuous, regularly spaced bands, 1-2 cells wide (reticulate), sometimes discontinuous portions tending to diffuse-in-aggregates, in 4-8(-10)-celled strands. Rays 8-10/mm, narrow, 1-2(-3)-seriate, c. 0.6 mm high, highest rays up to 1.3 mm, typically the 2-3-seriate portion as wide as uniseriate portion, heterocellular (Kribs type heterogeneous II and I), uniseriate rays mostly made up of upright cells. Prismatic crystals sometimes in chambered vertical parenchyma cells, more frequently in single upright or sometimes in chambered ray cells; starch grains frequent in parenchyma and ray cells; cells otherwise clear of extraneous coloured materials.
Species studied: Endospermum chinense Benth., Endospermum diadenum, Endospermum medullosum, Endospermum moluccanum, Endospermum peltatum.
Superficially, Endospermum wood resembles the wood of Alstonia, Dyera, Hevea and Aleurites. It can be differentiated easily from Alstonia and Dyera by the absence of latex tubes, latex traces and vestured pits. Aleurites wood has narrower and very heterocellular rays, Hevea wood has more abundant tyloses and more extraneous materials, and the wood has a pinkish tinge.

Sesendok is a light-demander and hence is one of the pioneer species in logged-over or secondary forest. Young trees grow fast in sunlight. On optimal sites in Malaysia, 3-year-old trees of Endospermum diadenum may reach 9.5 m height and 13.5 cm diameter. However, the maximum diameter attained at 40 years for the same species in Malaysia was only 42 cm.
The architecture of sesendok trees is according to Aubréville's model. The trunk is monopodial and the growth is rhythmic. The crown of young trees is usually pagoda-like, but in mature trees it becomes dome-shaped.
Sapling leaves are often strongly peltate. Usually, trees flower every year, and in Malaysia Endospermum diadenum often even flowers twice a year. Mature fruits are present 2-3 months after flowering. Trees 3 years old may already produce viable seeds. Endospermum diadenum is strictly dioecious, just like most other Endospermum species; female trees were found to have on average a thicker bark than male trees. The branches of some species are hollow and inhabited by ants (e.g. Camponotus quadriceps). The occurrence of ants in the branches is mainly confined to Endospermum moluccanum and Endospermum myrmecophilum, but sometimes they are also present in Endospermum medullosum. The ants are probably attracted by gland secretion.

The genus Endospermum belongs to the tribe Gelonieae and the subtribe Endosperminae. When sterile, species of Endospermum are sometimes confused with Macaranga which belongs to a different tribe. Endospermum differs from the latter by the filaments which are united at base (free in Macaranga), the broad, discoid stigma (short to long but never discoid in Macaranga), the drupaceous fruit (capsular in Macaranga), and, moreover, Endospermum trees are generally much bigger. There are distinct anatomical differences between the two genera too.
Although Endospermum malaccense is a full synonym of Endospermum diadenum, it is still often used, especially within Malaysia, which causes some confusion.
The wood of Endospermum chinense Benth. is used in its area of distribution, which covers Assam (India), Burma, Thailand, northern Vietnam and southern China.

Sesendok occurs in both primary and secondary forest and is often associated with streams or is found in waterlogged or even swampy forest. However, it also occurs on well-drained sites. It generally occurs scattered but stands where sesendok is dominant or even almost pure stands have been reported. Sesendok is often found in association with other typical swamp forest species such as Campnosperma spp., Cratoxylum spp., Lophopetalum spp. and Terminalia spp. Most Endospermum species, but especially Endospermum diadenum, are known as opportunist species characteristic of gaps in the forest and hence are common in areas with shifting cultivation. This is surprising, as the proportion of viable seeds may be as low as 0.1%. It is not clear how a pioneer species can succeed with such a low reproductive rate. Sesendok generally grows on low, flat to undulating country or sometimes on hillsides from sea-level up to 1000(-2000) m altitude and generally in areas without a pronounced dry season.

Seeds of Endospermum diadenum are often heavily predated by insects, making it difficult to obtain viable seeds. In the Philippines Endospermum peltatum is, however, propagated mainly by seeds. The fruits are soaked in water for 24 hours and then macerated to separate the seeds. These are sun dried for 2-3 days. They can be stored in polyethylene bags at a temperature of 15.5°C. If stored for more than one month, the seeds become dormant and can only be used for sowing in the next season. Seeds buried 30 cm deep retain their viability for more than 9 months. Before sowing the seeds are soaked in water overnight.
The seeds are broadcast in raised seed-beds. In Malaysia the highest germination rate (80%) was obtained when using a 1 : 3 mixture of sand and organic topsoil. After sowing, the seeds are covered with about 2 cm of soil, and the seed-bed is mulched with dry grass, and subsequently watered. Usually the seeds start to germinate after about 24 days. Seedlings are potted when they have 2-4 leaves (about 20 days after germination) in a sterilized mixture of 50% organic topsoil and 50% sandy loam. Only vigorous seedlings of 20-30 cm tall should be planted into the field.
In Malaysia it is suggested to use wildlings for planting because seed is scarce. Transplanted wildlings suffer high mortality unless care is taken to minimize root damage, but with appropriate care the survival rate may be as high as 70%. The survival rate of young trees of Endospermum diadenum after 2 years is 70-90%.
In the Philippines (Mindoro and Mindanao) natural regeneration of Endospermum peltatum is abundant 2-3 months after logging along with other secondary species. Approximately 35% of the seedlings survive after 6 months.

Natural stands of sesendok are managed in the same way as a mixed dipterocarp forest; this generally means selective cutting systems with a diameter limit of 50 cm or 60 cm, and, when necessary, enrichment planting.
Seedling growth may be improved by applying fertilizer at the time of planting. The logging system employed for plantations is either clear cutting or by diameter limit (for matchwood and pulpwood often 30 cm). The rotation for clear cutting depends on site productivity; for Endospermum peltatum it is often 15-20 years.

Nursery seedlings may suffer from damping-off. To prevent this disease, a copper oxychloride solution is often applied. In Peninsular Malaysia, fruits of Endospermum diadenum are subject to a high degree of insect predation, resulting in a very small proportion of seeds reaching maturity. Endospermum diadenum can be heavily defoliated by caterpillars of the moth Uraptevoides astheniata, with devastating effect on its growth.

The logs float in water and can be transported by river. Sesendok wood is easily affected by sapstain fungi. If processing of logs is delayed, appropriate prophylactic treatment must be applied to minimize unsightly discoloration of the wood.

The mean annual increment of Endospermum peltatum in the Philippines is reported as 2.1-2.2 m³/ha, in terms of stocked volume. For an average site, the yields of plantations of 10 years old, 15 years old and 20 years old are 67 m³/ha, 140 m³/ha and 236 m³/ha, respectively.

A fair supply of the major species of sesendok is still available in the Malesian region (particularly Endospermum diadenum and Endospermum peltatum). They do not seem to be in immediate risk of genetic erosion, as they occur and regenerate particularly in secondary forest and in former shifting cultivation areas. Besides, plantations have already been established to some extent, e.g. in the Philippines and Peninsular Malaysia. Because most sesendok species are pioneers, they will not easily become endangered.
Several species are only known from one or a few collections. They are apparently rare and need protection. These are Endospermum banghamii Merr. from northern Sumatra, Endospermum domatiphorum J. Schaeffer from Papua New Guinea, Endospermum ovatum Merr. from Mindanao (the Philippines), Endospermum quadriloculare Pax & Hoffm. from southern Sumatra, and Endospermum ronaldii J. Schaeffer from Peninsular Malaysia.

Sesendok has merit as a plantation species, although it has a rather broad crown. It grows well in open areas, and it can also be used for enrichment planting in logged-over forest. The wood can be used for various end products, although it is not very suitable for construction purposes. However, information on nursery practices is still sporadic. The development of appropriate methods of propagation should be a research priority.

Ang, L.H., 1990. Effect of open and under planting on early survival and growth of Endospermum malaccense (sesendok), Alstonia angustiloba (pulai) and Shorea parvifolia (meranti sarang punai). Journal of Tropical Forest Science 3: 380-384.
Burgess, P.F., 1966. Timbers of Sabah. Sabah Forest Records No 6. Forest Department, Sabah, Sandakan. pp. 267-270.
Chew, T.K., 1980. Observations on the growth and seed production of planted sesendok (Endospermum malaccense) at Tekam F.R., Pahang. Malaysian Forester 43: 532-537.
Chinte, F.O., 1949. Growth and development of young stands of gubas (Endospermum peltatum Merr.). Philippine Journal of Forestry 6: 245-264.
Generalao, M.L. & Torrenueva, A.T., 1972. Silvical characteristics of gubas. Silvical Leaflet 12. Bureau of Forestry, Philippines. 14 pp.
Keating, W.G. & Bolza, E., 1982. Characteristics, properties and uses of timbers. Vol. 1. South-east Asia, northern Australia and the Pacific. Inkata Press Proprietary Ltd., Melbourne, Sydney & London. pp. 139-141.
Mohammed Shukari Midon, 1982. Malaysian timbers - sesendok. Malaysian Forest Service Trade Leaflet No 66. Malaysian Timber Industry Board, Kuala Lumpur. 6 pp.
Schaeffer, J., 1971. Revision of the genus Endospermum Bth. (Euphorbiaceae). Blumea 19: 171-192.
Whitmore, T.C., 1983. Euphorbiaceae, 31. Endospermum. In: Whitmore, T.C. (Editor): Tree flora of Malaya. 2nd edition. Vol. 2. Malayan Forest Records No 26. Longman Malaysia SDN Berhad, Kuala Lumpur. pp. 93-94.
Yap, S.K. & Razali Husin, 1980. The reproductive behaviour of sesendok (Endospermum malaccense). Malaysian Forester 43: 37-43.

W.M. America (general part, selection of species), D.S. Alonzo (properties), J. Ilic (wood anatomy), Nguyen Ba (wood anatomy), Nguyen Dinh Hung (wood anatomy)

Endospermum diadenum
Endospermum medullosum
Endospermum moluccanum
Endospermum myrmecophilum
Endospermum peltatum

America, W.M., Alonzo, D.S., Ilic, J., Nguyen Ba & Nguyen Dinh Hung, 1993. Endospermum Benth.. In: Soerianegara, I. and Lemmens, R.H.M.J. (Editors): Plant Resources of South-East Asia No 5(1): Timber trees; Major commercial timbers. PROSEA Foundation, Bogor, Indonesia. Database record: prota4u.org/prosea

The following species in this genus are important in this commodity group and are treated separatedly in this database:
Endospermum diadenum
Endospermum medullosum
Endospermum moluccanum
Endospermum myrmecophilum
Endospermum peltatum