Elaeocarpus (PROSEA Timbers)

Plant Resources of South-East Asia Introduction

List of species

Elaeocarpus L.

Protologue: Sp. pl. 1: 515 (1753); Gen. pl., ed. 5: 230 (1754).

Family: Elaeocarpaceae

Chromosome number: x= unknown; 2n= unknown

Vernacular names

• Jenitri, quandong (trade names). Oil-fruit (En). Brunei: perius-perius, sengkurat, suragam
• Indonesia: bengkinang, mendang (Indonesian, Kalimantan), mentanahan (Kutai, East Kalimantan)
• Malaysia: sengkurat (general), kungkurad (Sabah), mendong (Peninsular)
• Papua New Guinea: Papua New Guinea quandong (En)
• Philippines: kalomala (general), hunggo (Filipino). Burma (Myanmar): thitpwe
• Thailand: ma mun
• Vietnam: côm.

Origin and geographic distribution

Elaeocarpus comprises some 300 species occurring from Madagascar and Mauritius to Sri Lanka, India, Indo-China, China, Japan, Thailand, throughout the Malesian region, east to Hawaii and Polynesia (as far as Rarotonga), south to Australia and New Zealand. Malesia harbours the majority of species (some 250); Papua New Guinea alone has about 70 species, Borneo at least 50 and Peninsular Malaysia about 30.

Uses

The wood of Elaeocarpus is used for light interior construction, weatherboard, boat building, aircraft building, furniture, joinery, scantlings, mouldings, boxes, pallets, shuttering, brushware, turnery, oars, match splints and carvings. It is occasionally used for the production of blockboard and as core stock and face veneer for plywood. It is suitable for the manufacture of particle board, fibreboard and pulp and paper.

E. angustifolius has been used for reforestation in Java whereas E. grandiflorus is planted as an ornamental. Elaeocarpus logs are suitable for the cultivation of shiitake mushrooms. The fruits of most species are edible. Leaves and seeds are sometimes applied medicinally, principally as a tonic, but also against sores, syphilis and as a diuretic. A decoction of the bark and leaves of E. floribundus has been used in Palembang, Sumatra to treat inflammation of the gums. The fruits of E. angustifolius are well-known in Hindu religion and the ancient Indian system of medicine in the treatment of mental diseases, epilepsy, hypertension, asthma and liver diseases. Stones are sometimes polished and used to make necklaces, bead chains or rosaries, formerly also for various buttons. Bark is used as twine in house construction.

Production and international trade

As supplies are generally limited, Elaeocarpus wood is mainly sold in mixed consignments of medium-weight hardwood. In 1996 Papua New Guinea exported almost 7000 m³of "quandong" logs at an average free-on-board (FOB) price of US$ 99/m³.

Properties

Elaeocarpus yields a lightweight to medium-weight hardwood with a density of (265-)315-700(-820) kg/m³at 15% moisture content. Heartwood straw, yellowish-white to pale yellow-brown or pinkish-brown, not clearly differentiated from the white to pale grey-brown, 4-8 cm wide sapwood; grain usually straight, sometimes shallowly interlocked; texture very fine to moderately fine and even; wood lustrous. Growth rings indistinct to the naked eye but distinct with a hand lens, very variable in width, sometimes boundaries indicated by thicker-walled fibres in latewood and a band of marginal parenchyma in the earlywood; vessels moderately small to medium-sized, occasionally moderately large, solitary and in radial multiples of 2-4(-7), multiples predominating, with occasional clusters, tyloses present and abundant in some species including E. calomala and E. undulatus ; parenchyma sparse to absent, apotracheal in marginal or seemingly marginal bands, just visible to the naked eye, sometimes paratracheal vasicentric, indistinct even with a hand lens; rays of 2 distinct sizes very distinct, moderately fine to medium-sized, visible on transverse section, and extremely fine, visible only with a hand lens; ripple marks absent; vertical traumatic canals present in tangential series in some species.

Shrinkage upon seasoning is low but the wood is prone to blue stain, sap-stain and insect attack. Prophylactic treatment should be undertaken prior to seasoning. Boards 13 mm and 38 mm thick of E. angustifolius take respectively 3 and 4.5 months to air dry. Back-sawn stock of 50 mm may develop slight warp and surface checks. The wood is soft to hard and very weak. It is generally easy to saw and work, takes a moderate to good finish and stock turns and moulds easily. It rotary peels well. The wood is non-durable when exposed to the weather or in contact with the ground. The sapwood is permeable, penetration of heartwood good in some material, patchy in others; the retention of E. angustifolius by the pressure treating method is 526 kg/m³for sapwood and 43 kg/m³for heartwood. The heartwood of Elaeocarpus is susceptible to dry-wood termites. The sapwood is susceptible to Lyctus .

The gross energy value of the wood of an unidentified Elaeocarpus species was reported to be about 20 535 kJ/kg.

See also the tables on microscopic wood anatomy and wood properties.

Botany

Shrubs or small to fairly large, or occasionally large trees up to 40(-50) m tall; bole straight, cylindrical, columnar or poorly shaped, branchless for up to 18 m, up to 80(-160) cm in diameter, sometimes with steep buttresses up to 3(-5) m high, rarely with stilt roots; bark surface smooth to cracked or rugose or fissured, sometimes lenticellate, brown or grey, inner bark fibrous to granular, brown or yellowish-brown to reddish-brown or pink; crown often symmetrical. Leaves arranged spirally or alternate, simple, dentate or crenate or occasionally entire, with or without stipules; petiole often kneed at apex. Flowers in an axillary raceme, pendulous, 4-5-merous; sepals valvate; petals only slightly longer than the sepals, white, cream or greenish, generally toothed and/or fringed at apex; disk lobed, glabrous or hairy; stamens 10-many, inserted between disk and ovary or rarely on the disk, anthers with transverse apical slits; ovary superior, 2-7-locular with 2-12 ovules in each cell, style simple. Fruit an often bluish, purplish or brownish-green drupe; stone hard, with 1-7 seeds. Seedling with epigeal germination; cotyledons emergent, leafy; hypocotyl elongated; first 2 leaves opposite or alternate, subsequent ones alternate.

E. angustifolius has been planted in trials in Java where the mean annual increment of 10.5-year-old trees planted at about 60 m altitude was 1.1-1.3 m in height and 1.9-2.1 cm in diameter. When planted at about 650 m altitude the mean annual increment of isolated trees was 2.5 m in height and 4.7 cm in diameter. In the Solomon Islands the annual increment of E. angustifolius in gaps in natural forest is 0.4 m in height and in plantations 2.9 m in height and 3.9 cm in diameter. Trees often show Terminalia -like branching. Growth form is according to Aubréville's architectural tree model, characterized by a monopodial trunk with rhythmic growth and spiral or decussate phyllotaxis bearing tiers of branches with similar phyllotaxis and indefinite growth of branches. Young leaves are red, pink or purple; old leaves wither red or occasionally yellow. Trees are generally evergreen, but some, e.g. E. angustifolius , are briefly deciduous. They flower at regular intervals, often after a dry period, sometimes 2-3 times a year. In Peninsular Malaysia flowering often takes place in March-May and August-October. In West Java E. angustifolius carries fruits more or less throughout the year, but in Sulawesi only in October-November. Birds (including cassowaries), bats, rodents and pigs eat the fruits and thus disperse the seeds.

Probably because of ongoing speciation processes and hybridization, some species groups are regarded as "complexes" within which it is hard to recognize individual species. Several formerly recognized species have, for example, now been incorporated into one of the 7 subspecies of E. submonoceras . The genus Acronodia has been incorporated into Elaeocarpus . Elaeocarpus is occasionally regarded as a member of the tribe Elaeocarpeae within the family Tiliaceae .

Ecology

Elaeocarpus may be encountered in primary but more often in secondary rain forest at low to medium altitudes, but sometimes as high as 3500 m and, in Papua New Guinea, can be locally common in montane forest in association with Nothofagus . It may occur gregariously and is found in a wide range of habitats including coastal forest, freshwater swamp forest, kerangas and on ultrabasic soils.

Silviculture Elaeocarpus can be propagated from seeds (which do not tolerate desiccation). E. angustifolius has about 510 dry stones/kg and E. glaber about 590 dry stones/kg. The stones should be sown in the shade and those of E. floribundus have about 15% germination in 4-8 months, those of E. glaber about 50% and those of E. stipularis about 15% in 2.5-4.5 months. Sown fruits of E. petiolatus (Jack) Wallich have about 50% germination in 2.5-4 months. It has been recommended to open the stones and to sow the seeds. Elaeocarpus is not resistant to fire.

There are techniques for partially ring-barking flowering branches of E. angustifolius which results in smaller fruits and stones. These stones are highly esteemed by trade, mainly in India and Peninsular Malaysia.

Genetic resources and breeding

Most of the Elaeocarpus species are endemic and hence have a fair risk of genetic erosion.

Prospects

The very fast growth of Elaeocarpus holds potential for increased use in plantations for the production of raw material for wood-based panels or paper manufacture.

Literature

40, 70, 101, 125, 130, 150, 151, 162, 163, 198, 202, 202a, 203, 209, 235, 238, 260, 267, 298, 300, 302, 304, 346, 348, 360, 387, 402, 403, 405, 406, 427, 436, 464, 487, 536, 553, 632, 678, 780, 829, 831, 861, 933, 934, 974, 1038, 1039, 1123, 1164, 1196, 1197, 1218, 1221, 1232, 1239, 1242, 1248.