3598

5(1): Timber trees; Major commercial timbers

Lophopetalum Wight ex Arn.

Ann. Nat. Hist. 3: 150 (1839).

CELASTRACEAE

x = unknown; Lophopetalum wightianum: n = 20

Trade groups Perupok: lightweight hardwood, e.g. Lophopetalum javanicum (Zoll.) Turcz., Lophopetalum multinervium Ridley, Lophopetalum subobovatum King, Lophopetalum wightianum Arn.

Perupok. Brunei: adau, dual. Indonesia: perupuk (general), medang kerupuk (Sumatra), pasana (Kalimantan). Malaysia: dual (Sabah). Philippines: abuab (Pilipino). Burma: taung-yemaré. Thailand: phuamphrao (Trang), dimi (Kanchanaburi), samet-thung (Nakhon Ratchasima). Vietnam: ba kh[is]a.

Lophopetalum at present comprises about 18 species and occurs in eastern Pakistan, western India, Indo-China, Thailand and throughout the Malesian area except for eastern Java and the Lesser Sunda Islands. The main centres of endemism of this genus are in Borneo and New Guinea, each with 3 endemic species. Lophopetalum javanicum is the most widespread species; it occurs from Thailand towards New Guinea.

The wood of perupok is often attractively figured. This, in combination with its very easy working qualities, makes perupok especially suitable for joinery and cabinet work as well as for decorative veneer. Furthermore the timber is suitable for light general construction, interior finishing, panelling and furniture manufacture as well as for bobbins, matchboxes and pencils. The odourless and tasteless wood is used for food containers and tea chests. The untreated timber is non-durable and should be applied under cover and not in contact with the ground. The timber is suitable for veneer and plywood production. A special application of perupok is for the manufacture of quality wooden mathematical instruments.
The bark of most species yields a strong poison, which is used locally as dart poison. The bark is also inflammable due to the presence of oil in a thin outer layer and is used as tinder.

Perupok has been generally used on a local scale and used not to be a very important export timber. It has gained importance, however, from the end of the 1980s, e.g. in Kalimantan.
Export figures from Peninsular Malaysia indicate that in 1983 3200 m³ of sawlogs with a value of US$ 125 000 was exported to Singapore, and in 1984 2500 m³ with a value of US$ 100 000. In 1987 logs with a volume of 13 500 m³ and a value of US$ 940 000 (US$ 70/m³) were exported from Sabah and in 1992 23 000 m³ of logs and 27 000 m³ of sawn timber with a total value of US$ 13 million. Sarawak exports a considerable amount of perupok. Perupok is very popular in Japan, and fetches very high prices. Indonesia exports perupok sawn timber to Japan but no export figures are available. In 1991 the price for sawn timber from Kalimantan was about US$ 1000/m³ and US$ 1400/m³ for mouldings.

Perupok is a lightweight, soft to moderately hard wood. The heartwood is light yellow or light yellow-brown with a pinkish tinge when fresh. The sapwood is not clearly demarcated from the heartwood, but generally somewhat paler. The density is (300-)480-640(-690) kg/m³ at 15% moisture content. The grain is fairly straight to interlocked, texture moderately fine and even. Planed surfaces are moderately lustrous, and the tangential surface shows a feathery pattern.
At 15% moisture content the modulus of rupture is 59-79 N/mm², modulus of elasticity (8000-)8600-12 600 N/mm², compression parallel to grain 30-43 N/mm², compression perpendicular to grain 5-6 N/mm², shear 7-9 N/mm², cleavage c. 34 N/mm radial and 42 N/mm tangential, Janka side hardness c. 2930 N and Janka end hardness c. 4470 N.
The rates of shrinkage are fairly low to moderate, from green to 15% moisture content 1.3-2.4% radial and 2.7-3.0% tangential, from green to oven dry up to 3.5% radial and 5.9% tangential. The timber air dries rapidly without serious degrade, except for slight cupping, surface and end checking and splitting. The wood is moderately liable to insect attack and blue stain during drying. Boards of 15 mm thick can be air dried in about 1 month, boards of 40 mm thick in 1.5 months. Kiln drying is satisfactory.
The wood is easy to saw, plain, bore and turn and gives a smooth finish, both in green and dry condition. The resistance to splitting when nailed is poor. The wood is easy to rotary peel into veneers of 1.5 mm thickness at a peeling angle of 91°. The veneer can be glued with urea-formaldehyde to produce good plywood. Perupok is not used for the manufacture of fibreboard or hardboard.
Perupok is rated as non-durable. Graveyard tests in Malaysia showed an average life of stakes in contact with the ground of 1-2 years. The heartwood is rather difficult to treat with preservatives. Using the open tank method and an equal mixture of creosote and diesel fuel, an average absorption of 61 kg/m³ has been achieved in Malaysia. The sapwood is more amenable to preservative treatment. Treated perupok wood can be very durable.
Wood of Lophopetalum javanicum contains 47% cellulose, 26% lignin, 19% pentosan, 1.4% ash and 0.1% silica. The solubility is 2.4% in alcohol-benzene, 1.7% in cold water, 3.4% in hot water and 16.5% in a 1% NaOH solution. The energy value is 19 240 kJ/kg.
The bark of Lophopetalum javanicum contains cardenolides (cardiac glycosides). At least 15 glycosides have been demonstrated to be present, e.g. several glycosides of strophanthidin and antiarigenin.

Small to fairly large (rarely very large), evergreen trees, up to 40(-62) m tall; bole usually straight, branchless for up to 30 m, and up to 70(-195) cm in diameter, fluted or with prominent buttresses up to 8 m high; outer bark surface usually smooth, hoop-marked to scaly and with large lenticels, pale grey-brown or chocolate brown and grey mottled, c. 10 mm thick, inner bark c. 6 mm thick, orange and yellow mottled to pink, sapwood white or sometimes yellow-brown; branchlets mostly dark, usually terete but flattened at the nodes. Leaves simple and entire, decussate or opposite, sometimes subopposite (occasionally a few leaves arranged spirally on the upper part of a branchlet), ovate to elliptical-oblong or lanceolate, rarely subpeltate; petiole distinct, sometimes very short; stipules consisting of a tuft of hair-like appendages, caducous. Inflorescence consisting of 1(-3) axillary, distinctly pedicellate to almost sessile thyrses; bracts deltoid or lanceolate, usually short-ciliate or fimbriate. Flowers bisexual, actinomorphic, 5-merous (except for the ovary), small and greenish; pedicel distinct, usually articulated at base; calyx saucer-shaped, lobes rounded or triangular, usually spreading, sometimes inflexed or reflexed; corolla with free and imbricate petals, inner surface usually partly covered with cristate, lamellate, or fimbriate appendages, rarely bearing a tuft of fleshy papillae at the central part (Lophopetalum beccarianum), sometimes naked; disk usually fleshy and more or less flat, in bud usually slightly concave, sometimes thin and saucer-shaped, upper surface smooth or denticulate, rounded or distinctly 5-lobed or 5-angled; stamens inserted on the disk, usually between pistil and margin, sometimes quite near the margin, alternating with the petals, rarely each of them in a small pit (Lophopetalumyes pallidum), filaments filiform, anthers dorso-centrally fixed, usually broadly ovoid or broadly ellipsoid, versatile; ovary superior but usually partly immersed in the disk, 3-celled, with 4-18 ovules in two rows in each cell on axile placentas, trigonal or pyramidal, gradually narrowed into a cylindrical, short style, with an obscure stigma. Fruit an oblong or slightly spindle-shaped, 3-lobed, 3-winged or 3-angular, dehiscing capsule. Seed oblong, flat, attached in the middle, winged all round, with little or no endosperm. Seedling with epigeal germination; cotyledons sessile, flat but succulent; first two leaves opposite, next leaves subopposite or arranged spirally.

- Macroscopic characters:
Heartwood pale yellow or pale yellow-brown with a pinkish tinge when fresh, not distinctly demarcated from the generally somewhat paler sapwood. Grain fairly straight to interlocked. Texture fine to moderately fine and even; wood with a medium lustre and an attractive feathery figure on the tangential surface. Parenchyma distinct to the naked eye, in wide darker concentric bands, regularly spaced, forming a growth ring-like pattern with lighter fibre layers; vessels sometimes with white deposits.
- Microscopic characters:
Vessels diffuse, usually 5-12/mm², infrequently solitary, usually in radial multiples of 2-3, rarely in small clusters, 80-160 µm in tangential diameter; perforations simple; intervessel pits alternate, round, 2-3 µm; vessel-ray and vessel-parenchyma pits similar to intervessel pits but half-bordered; tyloses absent. Fibres in a more or less distinct radial alignment, 800-1200 µm long, very thin-walled (wall 1.5-2 µm thick), with small, more or less distinctly bordered pits confined to the radial walls. Parenchyma abundant, apotracheal, in regularly spaced concentric bands, (2-)4-5 cells wide. Rays 12-17/mm, homocellular (Kribs type homogeneous), uniseriate, rarely with biseriate portions. Crystals prismatic, generally in chambered axial parenchyma cells, often in chains of up to 25 chambers.
Species studied: Lophopetalum beccarianum, Lophopetalum javanicum, L. torricellense Loes.

During germination, the hypocotyl and taproot emerge from the margin at the side of the seed. The hypocotyl elongates up to 2 cm, carrying the enclosed, sessile cotyledons above the soil level. The leaves of the leader shoot of saplings are generally alternate, whereas those of the branches are opposite. Branching is diffuse.
Generally, perupok flowers and fruits annually or even 2-3 times per year. The flowers, having a nectariferous disk, are insect-pollinated. The winged seeds are probably dispersed by wind.

The genus Kokoona is nowadays usually treated as different from Lophopetalum, although it is closely related. It differs in both floral and seed characteristics. Lophopetalum has imbricate petals, generally with appendages, and seeds with a wing all around, whereas Kokoona is characterized by contorted petals without appendages and seeds with a unilateral wing. The distinction is supported by characteristics of the wood anatomy. The wood of Kokoona was formerly traded together with Lophopetalum as perupok but is now traded separately as 'mata ulat'. It is generally heavier than perupok (density usually over 800 kg/m³ at 15% moisture content). The genus Lophopetalum has been merged with Solenospermum. The latter has also been treated as a distinct subgenus within Lophopetalum.

Perupok occurs in a wide variety of primary lowland forest types. It grows on flat or undulating land, ridge tops, hillsides, near streams and in peat or freshwater swamps on both clay and sandy soils. It generally avoids areas with good drainage and is neither tolerant to sediment brought in by floods nor to salt water. Perupok is found from sea-level up to 1500(-2500) m altitude. In some swamp areas in eastern Kalimantan Lophopetalum multinervium is dominant and occurs in association with Cephalomappa spp., Eugenia spp., Litsea spp., Myristica spp. and Shorea spp.

Germination of perupok seeds has been reported to be fair and more or less simultaneous. Germination usually starts within 15 days after sowing, but may sometimes take more than a month.
Perupok can also be propagated by cuttings and wildlings. Growing wildlings in a nursery bed gave good results and properly treated cuttings showed a survival rate of 90%.

Not much is known about appropriate management of natural perupok stands. From logged-over forest in East Kalimantan it is reported that 2 years after logging natural regeneration is abundant, in particular on rather open places. This may indicate that selective logging can be successfully practised. A diameter limit of 40 cm has been recommended in Indonesia.

Perupok seedlings are often attacked by swamp crabs. Enrichment planting using seedlings 40 cm tall has been recommended to counterbalance possible attack.

Logging of perupok trees is often not easy, because they usually grow in swampy areas. The problems encountered in harvesting are comparable to cutting ramin (Gonystylus bancanus (Miq.) Kurz). Woodslide tracks are often made to reach the trees to be felled, and logs must be hauled on wood sleds by manpower. Freshly unbarked perupok logs are very vulnerable to blue stain and should be quickly removed from the forest.

In East Kalimantan a survey was made of primary and logged-over perupok forest. Of the about 400 trees of more than 10 cm diameter present in one ha of primary swamp forest along the Betayau river, 43% (with a volume of 141 m³/ha) were identified as perupok. Perupok constituted 12.5% (with a volume of 22 m³/ha) of the trees over 10 cm diameter in the same forest type but logged over 2 years before. However, in swamp forest along the Pimping river logged more than 2 years ago, 84% of the trees (with a volume of 340 m³/ha) proved to be perupok. The yield can thus be very high locally.

Perupok timber is currently in great demand because it is considered as very decorative. The increasing efforts to meet the demand might easily result in genetic erosion, particularly of the species which are narrow endemics.
Selection of superior mother trees of Lophopetalum floribundum, Lophopetalum javanicum and Lophopetalum multinervium has been carried out in East Kalimantan.

Being of increasing economic interest, perupok has good prospects but the exploitation of stands of perupok as practised now is seldom based on sustainable management. Much more research effort is needed, especially on growth, planting and yield on a sustainable basis, to ensure the availability of this timber in the future.

Ashton, P.S., 1988. Manual of the non-dipterocarp trees of Sarawak. Vol. 2. Sarawak Branch for Forest Department, Sarawak. pp. 102-109.
Bratawinata, A.A., 1990. Studi tentang Lophopetalum javanicum (perupuk) pada tipe hutan rawa S. Betayau dan S. Pimping areal PT Industri Kehutanan Indonesia I Tarakan [Study on Lophopetalum javanicum (perupuk) in the swamp forests of the rivers Betayau and Pimping in PT Industri Kehutanan Indonesia I area Tarakan]. Paper prepared for discussion forum on 'Sustainable development of perupuk timber and maintainance of logged over stands'. Industri Kehutanan Indonesia I. 20 pp.
Burgess, P.F., 1966. Timbers of Sabah. Sabah Forest Records No 6. Forest Department, Sabah, Sandakan. pp. 76-80.
Cockburn, P.F., 1976. Trees of Sabah. Vol. 1. Forest Department, Sabah, Kuching. pp. 58-61.
Ding Hou, 1962. Celastraceae - I. In: van Steenis, C.G.G.J. (Editor): Flora Malesiana. Ser. I, Vol. 6. Wolters-Noordhoff, Groningen. pp. 227-291.
Kochummen, K.M. & Whitmore, T.C., 1983. Celastraceae. In: Whitmore, T.C. (Editor): Tree flora of Malaya. 2nd Edition. Vol. 1. Malayan Forest Records No 26. Longman Malaysia SDN Berhad, Kuala Lumpur. pp. 156-171.
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. 100-104.
Menon, P.K.B., 1964. Perupok wood. Malayan Forester 27: 18-21.
Wagner, H., Habermeier, H. & Schulten, H.R., 1984. The heart glycosides of the arrow poison of Lophopetalum toxicum. Helvetica Chimica Acta 67(1): 54-64.
Wong, T.M., 1983. Malaysian timbers - perupok. Malaysian Forest Service Trade Leaflet No 76. Malaysian Timber Industry Board, Kuala Lumpur. 8 pp.

J. Kartasubrata (general part), R.H.M.J. Lemmens (properties), S. Sudo (wood anatomy), M.H.A. Hoffman (selection of species)

Lophopetalum beccarianum
Lophopetalum floribundum
Lophopetalum javanicum
Lophopetalum ledermannii
Lophopetalum multinervium
Lophopetalum pachyphyllum
Lophopetalum pallidum
Lophopetalum rigidum
Lophopetalum subobovatum
Lophopetalum wightianum

Kartasubrata, J., Lemmens, R.H.M.J., Sudo, S. & Hoffman, M.H.A., 1993. Lophopetalum Wight ex Arn.. 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:
Lophopetalum beccarianum
Lophopetalum floribundum
Lophopetalum javanicum
Lophopetalum ledermannii
Lophopetalum multinervium
Lophopetalum pachyphyllum
Lophopetalum pallidum
Lophopetalum rigidum
Lophopetalum subobovatum
Lophopetalum wightianum