Syzygium (PROSEA Timbers)

Plant Resources of South-East Asia Introduction

List of species

Syzygium Gaertner

Protologue: Fruct. 1: 166 (1788).

Family: Myrtaceae

Chromosome number: x= 11;S. cumini: 2n= 22, 44, 55, 66,S. grande:n= 11,S. malaccense: 2n= 22,S. nervosum: 2n= 22,S. oblatum:n= 11,S. samarangense: 2n= 33, 44, 66, 88, 110

Trade groups

Kelat: medium-weight to heavy hardwood, e.g. Syzygium buettnerianum (K. Schumann) Niedenzu, S. claviflorum (Roxb.) A.M. Cowan & J.M. Cowan, S. fastigiatum (Blume) Merr. & Perry, S. grande (Wight) Walp., S. longiflorum K. Presl, S. nervosum DC., S. polyanthum (Wight) Walp., S. syzygioides (Miq.) Merr. & Perry.

Vernacular names

• Kelat
• Indonesia: ki tembaga, jambu laut
• Malaysia: jambu (Peninsular), obar (Sabah), obah (Sarawak)
• Papua New Guinea: water gum
• Philippines: makaasim. Burma (Myanmar): thabye-gui
• Thailand: wa, daeng.

Origin and geographic distribution

Syzygium is a very large genus with about 1000 species occurring in the African and Asian tropics. About 70 species are found in Indo-China, 80 in Thailand, 190 in Peninsular Malaysia, 50 in Java, 165 in Borneo, 180 in the Philippines and 140 in New Guinea. The major areas of endemism are the Philippines and New Guinea (with about 80% of the species endemic), and Borneo and Peninsular Malaysia (with about 60% of the species endemic), although the large number of endemic species might partly reflect an insufficient comparison between the species of different areas.

Uses

The wood is used for heavy and light construction, house construction (posts and poles), window sills, furniture, flooring, telegraph poles, ships, bridges, railway sleepers, bottom boards of railway carriages, implements, fibreboard, and veneer and plywood. It is also used for charcoal and as fuelwood.

The fruits of some species are edible. Several species are commonly cultivated for their edible fruits, such as S. aqueum (Burm.f.) Alston, S. cumini (L.) Skeels, S. jambos (L.) Alston, S. malaccense (L.) Merr. & Perry and S. samarangense (Blume) Merr. & Perry. The bark of some species has been used for dyeing materials brown, red or black, or for tanning fishing-nets and leather, and for caulking boats. The bark, roots, young shoots, leaves and fruits are used in local medicine. The aromatic leaves are used as a spice for food; the use of the flower buds of S. aromaticum (L.) Merr. & Perry (clove) as spice is well known. The leaves of some species are used as a substitute for tea. Some species are planted as ornamental trees along roadsides and in gardens, and as fire-break.

Production and international trade

Peninsular Malaysia exports small amounts of kelat timber. In 1983 the export of sawlogs was 4600 m³(51% to Singapore and 49% to Hong Kong) with a value of US$ 180 000. Kelat is occasionally exported from Peninsular Malaysia as "mixed medium hardwood". The export of kelat logs from Sabah was 20 000 m³in 1987 with a value of US$ 1.3 million. In 1992 Sabah exported 13 000 m³of kelat timber (84% as logs, 16% as sawn timber) with a total value of US$ 1.1 million (US$ 75/m³for logs, US$ 145/m³for sawn timber). In Papua New Guinea, Syzygium timber is ranked in MEP (Minimum Export Price) group 4; in 1992 low-quality saw logs fetched a minimum price of US$ 43/m³, and the best quality logs for peeling US$ 60/m³. Japan imports this timber mainly from Papua New Guinea (about 3% of the total import from Papua New Guinea), although small amounts are imported from elsewhere in South-East Asia and from the Solomon Islands.

Properties

Kelat is a medium-weight to heavy hardwood. The colour of the heartwood varies between species from greyish-brown, golden brown or pinkish-brown to red-brown or purple-brown. The sapwood is usually slightly paler and indistinctly to moderately sharply defined from the heartwood; it may reach 15-40 mm in width. The density of the wood is (450-)520-925(-1100) kg/m³at 15% moisture content. The grain is typically interlocked and often irregular and wavy, texture moderately fine and even. The wood is often figureless and non-lustrous, sometimes streaked with dark brown or blackish bands.

At 15% moisture content, the modulus of rupture is 64-116 N/mm², modulus of elasticity 10 900-17 600 N/mm², compression parallel to grain 42-59 N/mm², compression perpendicular to grain c. 6 N/mm², shear 5.5-13 N/mm², cleavage c. 33 N/mm radial and 49-56 N/mm²tangential, Janka side hardness 4070-6540 N and Janka end hardness 5250-5760 N.

The rates of shrinkage are variable, but in general they are rated as medium to moderately high: from green to 15% moisture content c. 1.9% radial and 3.3% tangential, from green to 12% moisture content 1.7-4.3% radial and 4.1-8.4% tangential, and from green to oven dry 3.1-5.0% radial and 5.1-9.0% tangential. Kelat timber air dries slowly to very slowly. In Malaysia boards 15 mm thick are reported to dry in 5 months and boards 40 mm thick in 10 months. Stock must be dried carefully and it is advised to weigh down the stacks and to apply end-coating; the timber isliable to end-splitting and checking. Kiln drying requires a mild schedule (in Malaysia kiln drying schedule C is recommended). Pre-drying before kilning is advised to prevent serious degrade. Timber of 80 mm × 80-130 mm can be dried in about 60 days in a climate chamber from 62% to 26% moisture content, but there is a tendency to surface checking, twisting and bowing. Boards 25 mm thick take about 9 days to kiln dry. A high-humidity treatment at completion of drying will generally relieve stresses. Form stability is good when dry.

In general, kelat can be converted without difficulty and machines well both green and air-dry. However, the harder and heavier wood of some species cannot be regarded as easy to saw. Air-dried timber is rated as satisfactory to rip-saw and cross-cut when using saws with tungsten carbid tipped teeth and a 20rake angle; narrow bandsawing may produce smooth surfaces but large amounts of sawdust may remain on saw faces. Saws with excessive hooks tend to chatter, but conversion in a modern mill presents little difficulty. Kelat wood planes easily; a very good surface is obtainable by surface planing with a 35rake angle, but flat-sawn material from Papua New Guinea shows a tendency to sporadic breakdown, and a reduction of rake angle is recommended. The wood takes a good finish. Kelat is sometimes a good turnery wood, but generally it is unsatisfactory for turning; material from Malaysia usually produces a smooth surface upon turning, but material from Papua New Guinea is reported to have a strong tendency to tearing. Boring is slightly difficult and produces a slightly rough finish. Boring of wood from Papua New Guinea may cause burns at 3000 rounds per minute when using two-wing straight-fluted dowell drills; there is no breaking out at drill exit. Mortising by using the chisel gives good results; satisfactory results are obtainable by using the oscillating cutter and the slot. Moulding with a double-fluted router bit produces satisfactory results. The wood nails and screws reasonably, but pre-boring is advised to prevent splitting especially close to the ends of boards. Stapling is satisfactory but some raising of face grain and splitting may occur when stapled quite close to the end-grain edge. Generally a good sanded finish can be obtained. The wood polishes well; transparent and stained coatings produce an attractive appearance. The gluing properties are reasonably good. Kelat is easy to cut into smooth, tight rotary-cut veneer of uniform thickness; the veneer dries with slight to moderate buckling and splitting, and the shrinkage is high.

Considerable variation in durability can be expected because of the wide range of densities between the wood of different species. The denser wood is rated as at least moderately durable in contact with the ground. The heartwood of water gum ( S. buettnerianum ) from Papua New Guinea is rated as durable to very durable; stake tests show a service life in contact with the ground of 8-15 years under tropical conditions. The heartwood of Philippine species such as S. bordenii and S. gratum is also rated as durable in contact with the ground. However, the average service life of test stakes of S. griffithii in contact with the ground in Malaysia was only 3.3 years. The wood is often slightly susceptible to powder-post beetle and termite attack and should be treated with preservatives when not used immediately. Attack by pinhole borers is unlikely to be serious. Sapwood and heartwood are susceptible to staining and should be treated with an anti-stain solution as soon as possible. A test in Peninsular Malaysia with untreated wood of S. chloranthum showed a service life of about 2 years under marine conditions. The heartwood is difficult to treat with preservatives, but the sapwood is more easily treatable. Wood of S. chloranthum showed an average absorption of 123 kg/m³when using a standard open tank treatment and an equal mixture of creosote and diesel fuel, but experiments in India showed that the wood of some Syzygium species is capable of absorbing only about 15 kg/m³, even by pressure treatment.

A test on the chemical properties of kelat wood in Malaysia gave the following results: 46% cellulose, 27.5% lignin, 11% pentosan and 0.5% ash; the solubility is 2.9% in alcohol-benzene, 6.6% in hot water and 14.5% in a 1% NaOH solution. The wood of some species is reported to be siliceous. The wood is rich in tannins. The energy value of wood of S. cumini is 20 240 kJ/kg.

Description

Small to medium-sized, sometimes large trees up to 45(-50) m tall, or rarely shrubs, with bole up to 150(-200) cm in diameter, often fluted at base or with small to moderately large buttresses, stilt roots sometimes present; bark surface highly variable, smooth, cracked, fissured, scaly or flaky, usually greyish-brown to reddish-brown, inner bark usually pink to dark red; twigs with a finely reticulate fibrous surface, usually glabrous. Leaves opposite and simple, glabrous, secondary veins close-set to widely spaced, with a distinct intramarginal vein, dotted with minute oil glands, petiolate but sometimes subsessile, lacking stipules. Inflorescence axillary, terminal, on leafless branches, or on branches or trunk, paniculate, racemose or umbellate, sometimes few-flowered and cymose or flowers fascicled on tubercles, bracts and bracteoles usually inconspicuous and deciduous. Flowers bisexual and regular, (3-)4-5(-10)-merous, clavate to obovoid in bud, often white but sometimes pinkish or reddish; calyx with short to long tube (globose to narrowly elongated-turbinate), the base often contracted into a pseudostalk, and with prominent to minute lobes (sometimes lobes absent and calyx tube truncate at apex), persistent in fruit or deciduous, in some species the calyx limb calyptriform; petals usually free but sometimes connivent or calyptriform, often with oily spots; stamens usually numerous, in several rows on the margin of the disk lining the calyx tube, usually free, anther sacs usually parallel, versatile,opening longitudinally, connective gland usually present; ovary inferior, 2(-4)-locular with few to many ovules in each locule, ovules usually radiating from a centrally located axile placenta, sometimes superimposed along a vertical placenta, style 1, usually filiform, short or long, stigma punctiform or rarely capitate. Fruit a berry with thick and fleshy, spongy, leathery or brittle rind, usually crowned by the remains of the calyx tube and/or lobes, often depressed at apex. Seeds 1-2 per fruit, rarely more; cotyledons thick, usually distinct from each other. Seedling with hypogeal or semi-hypogeal germination; cotyledons usually equal and peltate, petiolate or not; stem 4-angular near top; leaves decussate; tip of seedling often red.

Wood anatomy

• Macroscopic characters:

Heartwood yellowish-grey, brownish-olive, golden brown to reddish-brown or purplish-brown, usually indistinctly demarcated from the paler sapwood, but sometimes fairly sharply defined. Grain usually interlocked and more or less irregular, sometimes wavy. Texture moderately fine to fine and even; the wood is usually dull and without figure on planed surfaces, but sometimes vessel lines show up as white or dark red scratches because of the solid contents of vessels, often feeling rather rough to the touch, generally without characteristic odour or taste. Growth rings absent or inconspicuous, but occasionally concentric, 3-5 mm thick bands with few or no vessels present; vessels variable in size within the species, moderately few to numerous and fairly evenly distributed; parenchyma sparse to abundant, not visible without a lens; rays invisible or barely visible to the naked eye.

• Microscopic characters:

Vessels diffuse, 5-20(-38)/mm², solitary and in radial multiples of 2-3(-8), less frequently in clusters, round to oval, 70-200μm in tangential diameter; perforations simple; intervessel pits alternate, vestured, round to oval, 6-8μm in diameter; vessel-ray pits with reduced borders to simple, gash-like or round to oval, 15-20μm in diameter; reddish-brown or sometimes whitish gum-like deposits present; tyloses sparse to abundant, thin-walled. Fibres 900-2600μm long, non-septate or partly septate, thin-walled to thick-walled (walls c. 4μm thick), with simple to variably bordered pits. Parenchyma sparse to very abundant, entirely or predominantly paratracheal, aliform, sometimes limited to the abaxial sides of the vessels, locally confluent or completely confluent (e.g. S. polyanthum ) into numerous (6-12/mm), wavy, narrow bands; apotracheal parenchyma sparse to fairly abundant, usually consisting of diffuse crystalliferous strands, in up to 8-celled strands. Rays 8-18/mm, of 2 distinct sizes, uniseriate rays sparse to about as numerous as multiseriate rays; uniseriate rays consisting wholly of upright cells, 1-10 cells high; multiseriate rays (up to 10-seriate) up to 0.8 mm high, composed of mixed procumbent and upright to square cells, but in some species wholly or predominantly composed of procumbent cells (Kribs type heterogeneous II to III and homogeneous). Crystals comparatively rare in apotracheal parenchyma, when present solitary or in clusters and in some species in chambered cells; ray and parenchyma cells usually with orange-brown or reddish-brown deposits. Silica usually absent, but some species reported as siliceous. Intercellular canals and ripple marks absent.

Species studied: S. bordenii , S. cumini , S. fastigiatum , S. malaccense , S. nervosum , S. polyanthum , S. versteegii , S. xanthophyllum .

Growth and development

Most Syzygium species are evergreen, shedding their leaves gradually throughout the year, but they develop new leaves and flowers at seasonal intervals. They tend to flower gregariously. S. polyanthum can flower already when three years old. Some species flower and produce fruits more or less throughout the year (e.g. S. polyanthum and S. gracile ), but most species in Java flower from July to December and fruits are ripe in September to January. In Malaysia, some species flower once a year, after pronounced dry weather, but most species seem to flower twice a year after each dry spell, whereas a few species flower 3 or more times a year (e.g. S. grande usually flowers in Peninsular Malaysia from the middle of March to the middle of April, from the end of July to the middle of August and from the end of December to the middle of January, but sometimes there are additionally shorter periods of flowering). The flowers last for about 4-7 days and are usually pollinated by beetles and butterflies. Pollination of S. malaccense by bats ( Chiroptera , especially Eonycteris spelaea ) was observed in Peninsular Malaysia where bats feed on the nectar and pollen of several tree species. Other floral visitors are the yellow-bellied sunbird, honey bees and ants.

Fruit setting is during the rainy season and the fruits are ripe before the end of this season. The seeds are dispersed by squirrels, birds and small fruit bats, but seed dispersal of river-bank and seashore species may be by water.

Under favourable conditions in India, 40-year-old S. cumini trees attained a mean height of 24.1 m and a diameter at breast height of 31.5 cm.

Other botanical information

In the older literature Syzygium was regarded as a subgenus of Eugenia . In Malaysia, it is still the practice to treat Eugenia in its broadest sense (including Syzygium ). Indeed, there is no single morphological character by which the two genera can beconsistently distinguished. Although Eugenia sensu stricto and Syzygium differ in many characters, all these characters show at least some overlap (e.g. vegetative and/or reproductive parts usually pubescent in Eugenia (c. 90% of the species), usually not in Syzygium (c. 95%); bracteoles usually persistent and conspicuous in Eugenia (c. 80%), mostly fugacious and inconspicuous in Syzygium (c. 95%); pseudostalk of flower rarely present in Eugenia (c. 1%) and mostly present in Syzygium (c. 90%); cotyledons usually fused in Eugenia , usually distinct in Syzygium ; surface of seed-coat smooth in Eugenia , rough in Syzygium ). It is claimed that constant anatomical differences exist, particularly in floral vasculature (in Eugenia the vascular supply of the ovules is from the sides, i.e. transeptal, and there is no vascular tissue in the centre of the ovary below the placentae; in Syzygium it is through the centre of the gynoecium, i.e. axile, and all transections of the lower part of the ovary reveal vascular tissue in the centre). However, the floral vasculature of only a small fraction of the species has been studied. Evidence from wood anatomy, bark anatomy and pollen morphology also supports the separation of Eugenia and Syzygium . Syzygium is strictly confined to the Old World, Eugenia s.s. mainly to the New World, but not exclusively (e.g. Eugenia aherniana C.B. Robinson from the Philippines).

In the more recent literature Jambosa is considered as a synonym of Syzygium ; there is no single character or combination of characters by which Jambosa can be distinguished.

The genus Acmena is distinguished from Syzygium and Eugenia by the ruminate cotyledons, the apically dehiscent anthers, and the position of the placenta which is at the apex of the axis in each locule with pendulous ovules. The species of Acmena are often treated in the literature under Syzygium or Eugenia . The most important timber-producing species are the widespread Acmena acuminatissima (Blume) Merr. & Perry (synonyms: Eugenia cumingiana S. Vidal, Syzygium cumingianum (S. Vidal) L.S. Gibbs) and Acmena hemilampra (F. v. Mueller ex F.M. Bailey) Merr. & Perry from Papua New Guinea and northern Australia. Acmena will be treated separately, but not in this volume.

Acmenosperma differs in having 6-8 petals (usually), clavate flower buds (rare in Syzygium ), pendulous ovules (rare in Syzygium ) and ruminate cotyledons. The most important timber-producing species is the widespread Acmenosperma claviflorum (Roxb.) E. Kausel. Several authors, however, consider the differences as insufficient to separate it at generic level, and here this species is included in Syzygium as S. claviflorum (Roxb.) A.M. Cowan & J.M. Cowan.

S. nervosum DC. (synonym: S. operculatum (Roxb.) Niedenzu) is often considered to belong to the genus Cleistocalyx ( Cleistocalyx operculatus (Roxb.) Merr. & Perry), which differs from Syzygium only in the calyptriform calyx. As this feature is not supported by any other character and also rarely occurs in Syzygium , Cleistocalyx is not kept separate.

In Australia, the timber of several species is used for construction and traded as "satinash", e.g. S. canicortex B. Hyland, S. crebrinerve (C.T. White) L. Johnson, S. corynanthum (F. v. Mueller) L. Johnson, S. francisii (F.M. Bailey) L. Johnson, S. gustavioides (F.M. Bailey) B. Hyland, S. kuranda (F.M. Bailey) B. Hyland, S. luehmannii (F. v. Mueller) L. Johnson, S. papyraceum B. Hyland, S. sayeri (F. v. Mueller) B. Hyland, S. trachyphloium (C.T. White) B. Hyland and S. wesa B. Hyland.

Ecology

Syzygium can be found from sea-level to high in the mountains and is common over large areas, especially as understorey tree, in primary as well as secondary forest. Some species may dominate the vegetation, e.g. S. grande and S. syzygioides in forest bordering the rocky and sandy bays in Peninsular Malaysia. Very few species have been recorded from limestone. Most species are trees of the second and third storey of the forest. In montane heath forest Syzygium species are common understorey trees.

Propagation and planting

Syzygium is propagated by seed and sometimes by wildlings collected under adult trees. Species well known for their edible fruits are commonly propagated by cuttings, air layering, grafting, and budding. Tissue culture is still in an experimental stage.

The number of seeds per kg ranges from 3000-8500. Seed loses its viability very rapidly; after 4-6 weeks it hardly germinates anymore. Therefore, seed should be sown directly from the fruit on top of loose soil and under shade. It should not be buried, as this seriously reduces the germination percentage; for S. polyanthum it falls from 84% to 9% in Java. Germination is rapid, starting after 1-3 weeks and is complete after 5-12 weeks; 35-100% of the seed sown germinates.

Natural regeneration is generally profuse and seedlings can survive under shade for several years. Attempts to plant bare rooted seedlings of S. cumini have not been successful. Wildlings should be hardened off in the nursery before being planted; planting out wildlings immediately, with a ball of soil, was not successful because of the sudden change to the high light intensity at the planting site. Spacing S. polyanthum at 2 m × 3 m was considered to be too wide, as it gave rise to a unfavourable stem form and undesired branching.

Small Syzygium trees may be underplanted in forest plantations to reduce excessive development of weeds. Examples are S. pycnanthum Merr. & Perry, S. litorale (Blume) Amshoff and S. splendens , but they seldom yield timber-sized trees. S. polyanthum is also often used for underplanting. The leaves of these species decay relatively slowly and yield large quantities of mulch. Underplanting of kelat has been reported for teak ( Tectona grandis L.f.), pine ( Pinus spp.),kauri ( Agathis spp.) and Albizia procera (Roxb.) Benth. plantations.

Silviculture and management

Kelat can tolerate shade very well, and light shade promotes the formation of a desirable stem form and branching pattern. Natural pruning is good as soon as the canopy closes. Whenever pruning is necessary, wounds heal very fast. Some species coppice readily. Kelat needs a rather fertile soil. S. cumini may be considered for planting on swampy grounds because of its high resistance to oxygen deficiency.

Diseases and pests

On average kelat is not prone to fungal attacks of its roots. No major diseases have been recorded, but since the Syzygium species producing edible fruit are liable to several fungal diseases (e.g. leaf-spot, anthracnose, thread blight, root rot) it is likely that these diseases also occur to some extent in other species. Cryptosporella eugeniae is a virulent wound pathogen in clove ( S. aromaticum ), producing conspicuous red-brown staining of the wood; it can also attack the main stem of young trees and causes them to die when girdling is complete.

The following noxious insect species have been observed on Syzygium in Indonesia: Argyroploce mormopa (a tip-boring caterpillar on S. polyanthum ), Coccus viridus (feeding on the sap), Acarina (mites) and Alcides patruelis (larvae living in the shoots and beetles gnawing holes in the tender parts of the shoots). Termites can be a serious pest of young seedlings, and other pests include the red tree ant Oecophylla smaragdina and the coccid Saissetia eugeniae .

Yield

In pure plantations of S. polyanthum on fertile soil in Java the mean annual increment at 7 years was 21.5 m³of wood per ha, at 8 years in another plantation (spacing 2 m × 3 m) 9.1 m³of timber (clear bole wood volume) per ha, and at 17.5 years (spacing 1 m × 2.5 m) 7.4 m³of timber per ha. In natural forest in Riau, the same species showed a mean annual increment of 10.5 m³of wood per ha.

Genetic resources

In general, kelat is common throughout South-East Asia and many species are also common in secondary forest. However, such an immense genus undoubtedly contains numerous species which are rare or local endemics.

Ex-situ germplasm collection has been carried out in Malaysia for some species such as S. grande and S. polyanthum and several species producing edible fruits.

Prospects

In many parts of South-East Asia, most of the kelat timber today appears to be taken out in firewood fellings, and the genus is certainly of secondary importance as a source of timber. Further studies of kelat are desirable, since experience in Borneo, Papua New Guinea and northern Australia suggests that the timber of several species has potential for special purposes.

Literature

• All Nippon Checkers Corporation, 1989. Illustrated commercial foreign woods in Japan. Tokyo. p. 104.
• Burgess, P.F., 1966. Timbers of Sabah. Sabah Forest Records No 6. Forest Department Sabah, Sandakan. pp. 411-416.
• Chantaranothai, P. & Parnell, J., 1994. A revision of Acnema, Cleistocalyx, Eugenia s.s. and Syzygium (Myrtaceae) in Thailand. Thai Forest Bulletin 21: 1-123.
• Hartley, T.G. & Perry, L.M., 1973. A provisional key and enumeration of species of Syzygium (Myrtaceae) from Papuasia. Journal of the Arnold Arboretum 54: 160-227.
• Hyland, B.P.M., 1983. A revision of Syzygium and allied genera (Myrtaceae) in Australia. Australian Journal of Botany, Supplementary Series No 9: 1-164.
• Kochummen, K.M., 1978. Myrtaceae. In: Ng, F.S.P. (Editor): Tree flora of Malaya. A manual for foresters. Vol. 3. Malayan Forest Records No 26. Forest Research Institute Malaysia. Longman Malaysia SDN. Berhad, Kuala Lumpur. pp. 169-254.
• Lim, S.C., 1984. Malaysian timbers - kelat. Malaysian Forest Service Trade Leaflet No 88. Malaysian Timber Industry Board, Kuala Lumpur. 8 pp.
• Meniado, J.A., Tamolang, F.N., Lopez, F.R., America, W.M. & Alonzo, D.S., 1975. Wood identification handbook for Philippine timbers. Vol. 1. Government Printing Office, Manila. pp. 268-278.
• Merrill, E.D. & Perry, L.M., 1939. The Myrtaceous genus Syzygium Gaertner in Borneo. Memoirs of the American Academy of Arts and Sciences 18: 135-202.
• Schmid, R., 1972. A resolution of the Eugenia-Syzygium controversy (Myrtaceae). American Journal of Botany 59: 423-436.

All the species treated below probably belong to the genus Syzygium according to the concept defined under "other botanical information". However, for some species, especially from Malaysia, there is no name in Syzygium available and consequently these are treated under a Eugenia name. All names are arranged alphabetically according to epithet.