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Figure 10. Melaleuca endemism. The greatest endemism occurs in the south-central coastal region 

of Western Australia with some moderately strong areas of endemism in the north-western part of 

the south-west. There are some lesser areas of endemism in eastern Australia.

Figure 9. Melaleuca species richness calculated using a continuous gradient from 1 to 72 species








Species richness

High : 72


Low : 1










High : 9.92035


Low : 0.00518135


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oduction to the genus 



Fenton et al. 1977), particularly in South-East Asia and 

USA, can be ascribed to M. cajuputi and M. quinquen-

ervia and not M. leucadendra. Most current interest in 

the species for plantation establishment is in the Mekong 

Delta of Vietnam, where M. leucadendra outperforms 

the indigenous M. cajuputi subsp. cumingiana on season-

ally inundated and potentially acid-sulfate sites which 

are very difficult for tree establishment (Hoang Chuong 

et al. 1996).

Melaleuca alternifolia is planted for the production of 

essential oil in Australia—3,000 ha producing 450–500 

tonnes (t) of essential oil/year—but the total area planted 

and the total production worldwide is potentially twice 

this from plantings outside Australia in several countries, 

including China. Broombush (M. uncinata complex) 

plantings in Australia for brushwood fencing and related 

products exceed 1,000 ha.

There are extensive, but largely undocumented, plant-

ings of melaleucas as ornamentals, street and public park 

trees, shelterbelts on farms and for land reclamation in 

Australia and elsewhere.

Tolerance of difficult 


As well as being tolerant of periodic (Figure 12) or 

even continuous waterlogging, many of the wetland 

melaleucas will also survive and grow in moderately 

to highly saline soils (e.g. M. armillaris, M. bracteata, 

M. cuticularis, M. decussata, M. ericifolia, M. lanceolata, 

M. lateriflora, M. leucadendra, M. linariifolia, M. quinquen-

ervia, M. squarrosa, M styphelioides and the M. uncinata 

Figure 11.  Some of the variable habitats occupied by Melaleuca species: (A) a pure stand of tree-form 

M. quinquenervia in a coastal swamp in eastern Australia; (B) the shrub M. protrusa on a dry stony hillside in 

south-western Western Australia (WA); (C) shrubby M. sophisma under an overstorey of mallet in south-

western WA; and (D) trees of M. cuticularis on the edge of a wet, possibly saline area in south-western WA






2. I


oduction to the genus 



complex). A few melaleucas are tolerant of extremely 

saline conditions (e.g. M. halmaturorum and M. thyoides). 

Many of these same species are also tolerant of alkaline 

soils, drought and frost (Marcar et al. 1995; Marcar and 

Crawford 2004).

Melaleucas appear to employ a diverse range of 

physiological strategies to adapt to difficult growing 

conditions. For example, Naidu et al. (2000) found that 

species with the capacity to accumulate one or, prefer-

ably, more of the methyl prolines in their leaves were 

better adapted to saline and/or sodic soils than species 

that accumulated only L-proline. This was the case with 

M. cuticularis: Carter et al. (2006) found that the ability 

of this species to tolerate saline-waterlogged conditions 

was related to production of methyl proline, as well as 

regulation of foliar sodium, chloride and potassium 

concentrations. Ionic stress and the differential ability of 

seedlings of M. leucadendra provenances to adjust for a 

declining potassium concentration in leaf sap under com-

bined salt and aluminium stress was thought to be the 

main cause of variation in growth of 16 M. leucadendra 

provenances in a glasshouse trial (Nguyen et al. 2009). 

Mensforth and Walker (1996) found that the root dynam-

ics of M. halmaturorum in response to fluctuating saline 

groundwater contributed to the survival of this species in 

saline swamps. Melaleuca halmaturorum accessed water 

from deep in the profile in late summer when salt had 

accumulated in the surface soils and used rainfall and 

shallower groundwater after winter rains had replenished 

the profile. The ability of this species to take up water from 

saline substrates through maintenance of low leaf water 

potentials was also a contributing factor (Mensforth and 

Walker 1996).

Some wetland melaleucas, like the tropical M. leuca-

dendra group, develop aerial adventitious roots on their 

stems and within the papery bark to the height of the 

maximum water level during flooding (Figure 13). These 

are dense in aerenchyma cells which have large intracel-

lular air spaces that improve internal root aeration and 

gas exchange during inundation. The fine adventitious 

roots on the stems of M. quinquenervia in a seasonally 

inundated forest in northern Queensland, for example, 

were considered an important part of the reason that tran-

spiration in this species was unaffected by inundation of 

up to 24 weeks (McJannet 2008). In M. cuticularis, they 

appear to contribute to this species’ enhanced tolerance to 

combined salinity and waterlogging (Carter et al. 2006). 

Tanaka et al. (2011) reported that seedlings of M. cajuputi 

in the tropical peat swamps of southern Thailand were 

able not only to survive complete submergence for 8 weeks 

but also to photosynthesise and grow during this period. 

This was due to the strong development in the leaves and 

stems of submerged seedlings of schizogenously formed 

aerenchyma which improved uptake of gases from the 


Many melaleucas are highly fire-tolerant during all but 

the early seedling stages before a thick protective layer 

of bark has formed. Fire-ravaged individuals regenerate 

through stimulation of epicormic buds under the thick 

bark to sprout vigorously after fire in a process called 

coppicing (Figure 14). Populations may expand through 

fire-induced release of seed from serotinous capsules on 

the trees and stimulation of germination of seed in soil 


Some melaleuca species have the ability to root sucker, 

and through root extension and interconnectivity form 

Figure 12. Melaleuca cajuputi surviving and growing under seasonal inundation in the Mekong Delta of 

Vietnam: (A) a young planting as the inundation recedes; and (B) a dense plantation nearing rotation age



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oduction to the genus 




dense clumps of single clones. This is a common adaptive 

characteristic of wetland plants subject to very difficult 

conditions for survival, growth and sexual recruitment 

(see review in Robinson et al. 2012). Using DNA markers, 

Robinson et al. (2012) showed that the large, dome-shape 

stands of M. ericifolia in Dowd Morass, Gippsland Lakes, 

Victoria, were individual clones that did not intermin-

gle (phalanx growth habit) with adjacent clones. They 

speculate that this is also the case with other stands of 

this species in southern Australia. Melaleuca viridiflora 

also forms root suckers. Crowley et al. (2009) showed that 

population density of this species increased dramatically 

in grasslands and grassy woodlands in northern Queens-

land in the absence of fire by recruitment of suckers to 

the sapling layer.

Figure 13. Aerial adventitious roots on the stems of: (A) Melaleuca quinquenervia growing naturally in a 

seasonal swamp beside the Bensbach River, Western Province, Papua New Guinea; and (B) M. leucadendra 

planted in the Mekong Delta, Vietnam



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oduction to the genus 




Figure 14. Western Australian broombush, Melaleuca concreta, coppicing after fire



Some Melaleuca species were used extensively by the Aboriginal peoples of Australia 

for a wide variety of cultural uses (refer to Williams 2011 for a description of 17 species 

used by Aboriginal communities).

The papery bark of several, mainly tropical, melaleucas (e.g. M. argentea, M. dealbata, 

M. cajuputi, M. leucadendra and M. viridiflora) had many domestic uses, including 

water-repellent roofing material, raft-making, in food preparation, bandages, blankets, 

baby slings, body wraps in burial ceremonies and for dresses denoting marriage, to 

name but a few (Levitt 1981; Wrigley and Fagg 1993; Yunupingu et al. 1995; Blake 

et al. 1998; Puruntatameri et al. 2001; Wiynjorrotj et al. 2005; Williams 2011; Wiersema 

and León 2013). The leaves of species such as M. acacioides, M. argentea and M. leuca-

dendra were used as flavouring in cooking and M. argentea leaves were burnt to repel 

mosquitoes. The trunks of some species (e.g. M. cajuputi, M. leucadendra and M. viridi-

flora) were used for construction of canoes and shields.

‘Bee bread’ (produced from pollen) and honey were foods 

collected from native bee hives prevalent in Melaleuca 

swamp forests of M. acacioides, M. lasiandra, M. leuca-

dendra, M. minutifolia, M. nervosa and M. viridiflora in 

northern Australia (Williams 2011). Williams (2011) also 

notes reports of early explorers (e.g. Leichhardt in 1847 

and Mitchell in 1848) in northern Australia of the col-

lection by Aboriginal peoples of melaleuca honey and 

melaleuca flowers (e.g. from M. saligna). The latter were 

soaked in water to produce a sweet-tasting drink.

Melaleucas were an important source of dry-season 

water for the nomadic Aboriginal peoples (and early 

European explorers), particularly in the wet/dry tropics 

of northern Australia. Bulges in the trunks of individual 

trees of such species as M. argentea, M. cajuputi, M. deal-

bata, M. nervosa and M. viridiflora when undercut could 

yield about a litre of brackish but nevertheless potable 

water (Yunupingu et al. 1995; Puruntatameri et al. 2001; 

Wiynjorrotj et al. 2005; Williams 2011).

Melaleucas played an important role in traditional 

Abor iginal medicines. The leaves and inner bark of 

M. argentea and others like M. cajuputi and M. leucaden-

dra were used medicinally (coughs and colds, aches and 

pains, cuts and sores, ringworm, vomiting and diarrhoea 

and other malaises), either directly following crushing or 

burning (smoking medicine) and inhaling the odours or as 




3. U


a liniment or drink after soaking the leaves or inner bark 

in water and heating (Blake 1968; Levitt 1981; Aboriginal 

Communities of the Northern Territory 1993; Wrigley and 

Fagg 1993; Yunupingu et al. 1995; Puruntatameri et al. 

2001; Wiynjorrotj et al. 2005; Lassak and McCarthy 2011; 

Williams 2011). The bark of some melaleucas was used as a 

poultice on wounds and for splinting broken bones, where 

the juice of the bark was said to penetrate the skin and aid 

in healing (Williams 2011). The milky extract of squashed 

‘bee brood’ (bee pupae and larvae) collected from native 

beehives prevalent in melaleuca swamp forests was used 

as a topical antiseptic for sores, tinea and eye complaints 

(Williams 2011).

Ornamental, landcare, 

honey, bark and wood

Ornamental and amenity–horticultural use

Melaleuca species, especially the bottlebrushes, have long 

been popular garden subjects in Australia. The first Austral-

ian melaleucas to be cultivated, however, were grown in 

Europe, presumably from seed taken to England in 1771 

by Joseph Banks. Melaleuca armillaris, M. decora, M. erici-

folia, M. hypericifolia, M. nodosa, M. styphelioides and 

M. thymifolia were in cultivation by 1793 (Elliot and Jones 

1993; Wrigley and Fagg 1993). Seed and/or transplants of 

the bottlebrush species M. citrina and M. linearis also were 

taken to Europe in the late 1700s and these species rapidly 

became popular conservatory plants. Melaleuca citrina was 

in fact named and described (as Metrosideros citrina) in 

1794 from material cultivated in England and M. linearis 

was described in 1796 from material cultivated in Germany.

Many species (including cultivars derived from selec-

tion or from interspecific hybrids) are hardy in cultivation 

in Australia (Elliot and Jones 1982, as Callistemon; Elliot 

and Jones 1993; Wrigley and Fagg 1993, also as Callis-

temon; Holliday 2004; Stewart 2012, also as Callistemon). 

Some tolerate moderate levels of frost and others grow well 

in poorly drained soils. Because there are species of diverse 

habit, flower form and colour, and substrate preference 

in most of the major climatic zones within Australia, it 

is possible to select a species for a specific purpose, e.g. 

for a hedge, windbreak, specimen shrub or tree. Several 

species have particularly attractive papery bark and are 

worth cultivating for this feature. Several of the larger 

shrub and tree species are ideal for amenity plantings as 

street trees, screens for industrial sites, highway verges and 

so on. Many of the tree species are ideal for use in parks 

and large-scale landscape applications. The trees that have 

colourful, nectariferous flowers (Figure 15) usually attract 

nectar-feeding birds if these occur in the region.

There are surprisingly few melaleuca cultivars available 

in the horticultural industry in Australia and most, if not 

all, of these are selections of species. The bottlebrushes are 

an exception. Barriers to successful hybridisation between 

certain species apparently do not exist and, when grown in 

a common garden, bird- or insect-mediated hybridisation 

has resulted in the occurrence of hybrid plants. In many 

cases, selections have been named and propagated com-

mercially. The following species (as Callistemon) have been 

recorded as being a parent, or putatively a parent, of named 

cultivars: M. citrina, M. comboynensis, M. glauca, M. pachy-

phylla, M. phoenicea, M. polandii (doubtfully this species 

and more likely to have been M. hemisticta or M. pyrami-

dalis), M. recurva, M. salicina, M. subulata and M. viminalis 

(Elliot and Jones 1982; Wrigley and Fagg 1993). Much more 

Figure 15. Ornamental melaleucas: (A) Melaleuca ryeae, a shrub with profuse pink flowerheads; and (B) 

Melaleuca cultivar ‘Harkness’



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work needs to be done as far as bottlebrush breeding is 

concerned. There is considerable opportunity for breeders 

to select growth and colour forms of species and cross them 

with an aim of obtaining a particular combination of char-

acters. The two broad climatic zones that should be targeted 

for such hybridising endeavours are the tropical–subtropi-

cal and subtemperate zones in Australia and elsewhere.

As to other species groups within the genus, it seems 

there have been no hybridisation programs. The field is 

open for such programs to be initiated. The pom-pom-

flowered M. scabra group is an obvious candidate as there 

is much variation within this group that could be bred into 

novel, improved garden plants. Although many of the spe-

cies of the M. scabra group occur on leached, sandy soils, 

some of them occur on clay soils and these species may 

confer some degree of soil adaptability to hybrids. Mela-

leuca nesophila, an M. scabra group species of restricted 

range and habitat in the high rainfall, coastal part of south-

western Western Australia, is remarkably hardy and grows 

well on heavier soils in the dry Western Slopes region of 

New South Wales. Using species such as M. carrii, M. fabri, 

M. hamata, M. nematophylla, M. nesophila, M. oldfieldii, 

M. sapientes and M. systena—and there are many oth-

ers—it may be possible to develop hybrids of merit for 

Mediterranean and dry-temperate climates.

Another group with potential as garden plants is the 

M. fulgens group, and a hybridisation program involv-

ing such species as M. coccinea, M. elliptica, M. eximia, 

M. fulgens, M. lateritia and M. macronychia may result in a 

series of red- to orange-red-flowered, bushy plants to rival 

the bottlebrushes, as the species of the M. fulgens group 

also have bottlebrush inflorescences. Naturally occurring 

hybridisation in Melaleuca has been reported from a wide 

range of species (Craven 2006, p. 470) and it seems barriers 

to hybridisation within a species group or species complex 

are not absolute; in fact, where two or more species of the 

same group occur in biotic sympatry, hybridisation may 

be frequent.

An interesting application is the use of melaleucas as 

bonsai (known as penjing in China and cay canh in Viet-

nam). Bark texture, small leaves and flowering propensity 

are some of the criteria by which species are rated. Over 

60 species, varieties and cultivars of Melaleuca have been 

recorded by the Australian Plants as Bonsai Study Group 

as being grown in bonsai within Australia (Roger Hnatiuk, 

pers. comm.). Early use of melaleucas tended to mimic the 

styling of classic Japanese trees but in recent years bonsai 

artists are exploring the beauty of branches and crowns of 

old mature trees of the species found growing in nature. 

Bonsai, inspired by such forms, are beginning to be seen 

in public displays (Figure 16).

Notes on species of particular, or potential, value for 

ornamental and amenity–horticultural use are provided in 

the ‘Species accounts’ (Chapter 7). The main impediment 

to their wider use within Australia and elsewhere is the 

difficulty in obtaining planting material of superior colour 

and growth forms of the species, or forms from particular 

soil types.

Figure 16. Examples of bonsai melaleucas: (A) Melaleuca lateritia, usually a 2–3 m tall shrub from south-

western Western Australia; and (B) M. bracteata, usually a medium-size tree up to 22 m tall from inland and 

coastal northern Australia



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Land rehabilitation

Melaleuca comprises many species of trees and shrubs that 

are hardy and adaptable to a wide range of habitats and 

soils. They regularly occupy sites that are very challeng-

ing for tree survival and growth (Figure 17), as discussed 

in other sections of this volume. Their diversity in form, 

adaptability and utility sees them listed prominently 

among candidate species for planting for land reclama-

tion, with natural resource benefits including mitigation 

of salinity, waterlogging, and water and wind erosion. 

Biodiversity improvements, carbon sequestration and 

potential to increase farm income (e.g. through produc-

tion of brushwood fencing, essential oils and bioenergy) 

are among other commonly stated benefits of planting 

melaleucas on degraded lands.

Highly topical at present is the increasing problem of 

saline landscapes in Australia and elsewhere. There are 

over 4 million ha of secondary or human-induced saline 

soils in Australia, in addition to 29 million ha of naturally 

Figure 17. Salt-tolerant melaleucas: (A) Melaleuca halmaturorum on a saline site 

in southern Australia; and (B) M. atroviridis surviving on the margin of an area 

severely affected by secondary salinity in south-western Western Australia




3. U


occurring salt-affected lands (Marcar and Crawford 2004). 

The removal of native vegetation and development of annual 

agricultural systems in southern Australia, leading to ris-

ing watertables carrying soil-borne salt to the surface, are 

major contributors to salinisation of landscapes. Restoration 

of deep-rooted perennial vegetation can make a significant 

contribution to correcting this problem but it needs to be 

on a large scale to control salinity (Pannell and Ewing 2004). 

A range of Melaleuca species is suitably adapted to grow 

on saline sites (e.g. Figure 17), ranging from moderately 

(4–8 dS/m ECe) to extremely saline (>16 dS/m ECe) (Mar-

car et al. 1995; Department of Agriculture and Food Western 

Australia 2004; Marcar and Crawford 2004).

Melaleuca halmaturorum is an example of a temperate 

Melaleuca tree/shrub adapted to extremely saline condi-

tions, while M. leucadendra is among the tropical tree-form 

melaleucas adapted to highly saline conditions. Both spe-

cies are tolerant of waterlogging. Unfortunately, few of the 

presently recognised salt-tolerant melaleucas offer scope 

to growers for direct financial benefits, thus large-scale 

planting is not attractive. Melaleuca uncinata, one of the 

source species for brushwood (see below), and its relative 

M. atroviridis, are two exceptions. Melaleuca bracteata 

might have potential in the future if an industry were to 

develop around the production of betaines from its foliage.

Brushwood fencing and related products

Ornamental brushwood fencing comprising the grey 

stems, twigs and dry foliage of the M. uncinata complex 

of species (broombushes), hand-packed on wires in situ 

or, in more recent times, prefabricated in panels, has been 

in use in Australia for more than 80 years (McKelvie et al. 

1994) (Figure 18). It represents an important market for 

melaleucas, despite its small size compared with alterna-

tive fencing materials (e.g. 1% of the fencing market in 

Western Australia). Other uses of brushwood include 

manufacture of garden furniture, gazebos, pergolas, gates, 

hanging baskets and decorative bird feeders (Robinson 

and Emmott, no date). McKelvie et al. (1994) indicated 

that about 600,000 bundles of brushwood (each c. 25 kg, 

consisting of stems with foliage of 1.4–1.8 m in length and 

7–15 mm in diameter) were used in Australia each year, 

with predicted annual market growth of 5.5%.

Melaleuca uncinata is the most common broombush 

used for brushwood fencing. It is widespread in southern 

Australia, mainly south of the Tropic of Capricorn. Mela-

leuca uncinata is a hardy, bushy shrub to 7 m in height with 

multiple long, thin, woody erect stems topped with foliage 

(broom-like). It is adapted to a wide diversity of habitats 

and soils, mainly in semi-arid and arid Australia (see range 

given in its species description). Other broombushes in the 

M. uncinata complex having potential for brushwood fenc-

ing are the Western Australian endemics M. atroviridis, 

M. concreta, M. hamata and M. osullivanii (Robinson and 

Emmott, no date). Melaleuca acuminata and M. hamulosa 

are also worth trialling as alternative species as they have 

similar physical characteristics to the traditionally used 

M. uncinata (Peter White, pers. comm. 2012).

Until recent times, all harvesting of brushwood has 

been in native stands and producers are licensed by the 

various state governments. Overall, 50–70% of plants are 

harvested manually of which 90% can be expected to cop-

pice in a typical bush operation based on a broombush 

population of about 3,000 plants/ha. This yields between 

3–6 t product/ ha. The interval between harvests is 10–14 

years (Wrigley and Fagg 1993). Concerns about adverse 

environmental effects have seen the gradual withdrawal 

of public lands from resources available for harvesting and 

concerns have arisen about the sustainability of brushwood 

supply from native stands. The likely direct economic ben-

efits, complemented by the indirect benefits of establishing 

broombush on private lands for purposes such as shelter, 

salinity control, soil erosion control, biodiversity and 

diversification of farm income, have led to interest among 

some landholders in the drier regions of the southern 

states in developing commercial plantations of broombush. 

It is estimated that a total plantation area in the order of 

2,000–2,500 ha would be required to fully meet demand on 

a sustainable basis (Cameron 2003; AVONGRO 2007). The 

total area planted is not known but about 900 ha had been 

planted in the Avon catchment area of Western Australia 

alone by 2007 (AVONGRO 2007).

Various landcare agencies in Western Australia, South 

Australia and Victoria have published informative ‘fact 

sheets’ on growing broombush by either direct seeding or 

planting tube stock and readers interested in this topic are 

directed to these for detailed information (e.g. Bulman et 

al. 1998; Cameron 2003; Robinson and Emmott, no date). 

Until recently, broombush was regarded as being a single 

species, M. uncinata. It is now known that there are several 

species involved (Craven et al. 2004), a number of which 

are suitable for brushwood production as mentioned above.


Most melaleucas do not provide major honey crops. Clem-

son (1985), however, pointed out that many species assist 

indirectly with honey production by providing nectar and 

pollen, especially nectar, in sufficient quantities to stimu-

late brood-rearing and sometimes for use as stores. In this 

way, colonies are maintained and built up for subsequent 

major honey flows in other taxa.

Those which are important honey producers include 

the broad-leaved melaleucas. Melaleuca quinquenervia is 

a major source of honey in Australia and Florida (Blake 

and Roff 1972; Robinson 1981; Clemson 1985; Geary 1988) 

and similarly M. cajuputi in northern Australia and Viet-

nam (Brock 1988; Mulder 1992). Melaleuca leucadendra 

is also said to be an important source of honey in its area 

3. U



of natural occurrence (Roff 1966; Anderson 1993). The 

honeys from these species are variously described as light 

to dark amber in colour, with strong flavour and odour 

and of low density so they granulate readily. Their pollens 

are universally described as being a good source of protein 

utilised by bees in building up colonies.


The bark of Melaleuca species is still used today in the con-

struction of traditional houses in Papua New Guinea. It is 

used to line fernery baskets, for making bark paintings and 

the cork from the bark has been used in infants’ pillows 

and mattresses (Bootle 1983). The bark of M. cajuputi is 

used in parts of Malaysia as a luting material in boatbuild-

ing (Lum 1994; Lim and Midon 2001).



There is little reported on the fuelwood value of individual 

species in the genus Melaleuca. Apart from the state-

ment in Maiden (1889) that M. linariifolia wood made 

Figure 18. Facets of the brushwood fencing industry: (A) the multistemmed habit of species in the broombush 

complex (this is Melaleuca stereophloia); (B) a native broombush (M. uncinata) population; (C) broombush 

bundles in the field ready for transport; (D) transporting the bundles to market; (E) constructing a brushwood 

fence in situ; and (F) a typical brushwood fence








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a first-class fuel, most published reports of the fuelwood 

value of melaleucas refer to the larger-growing species 

in the tropical broad-leaved M. leucadendra group. The 

wood of M. quinquenervia, for example, is reported to be 

an excellent fuel and converts into good-quality charcoal. 

The reported calorific values for the wood and bark of this 

species are around 18,400 and 25,800 kJ/kg (4,400 and 

6,160 kcal/kg), respectively (Wang et al. 1981), but there 

is great variability in these values between trees (Wang 

and Littell 1983). The uniquely high heat of combustion 

of M. quinquenervia bark (equivalent to some coals) is 

due to the presence of a great amount of fatty substances 

in the bark (Wang et al. 1982). Keating and Bolza (1982) 

rated M. cajuputi and M. leucadendra as good fuelwoods, 

although often difficult to split because of interlocking 

grain. Gough et al. (1989) reported that the light wood of 

M. leucadendra was quick to ignite, with sooty acrid smoke 

initially produced from the burning bark.

Posts, poles, stakes and sticks

The stems of the larger melaleucas like M. cajuputi, M. leu-

cadendra, M. quinquenervia and many other species were 

regularly used in the round or roughly fashioned for use 

as posts, poles, piles, mine timbers and general construc-

tion materials (e.g. rafters for huts, fencing rails) in the 

early days of settlement in Australia (Maiden 1889). Posts 

were said to be durable in contact with fresh or salt water 

(e.g. M. cajuputi, Blake 1968), although Cherrier (1981) 

reported that durability of untreated M. quinquenervia 

posts in the ground was high for 1 year but declined 

thereafter, and replacement was necessary after about 3 

years. In present-day Vietnam, there is widespread use 

of the roundwood of the indigenous M. cajuputi and the 

introduced M. leucadendra for piles, poles and general 

construction materials (Figure 19).

A specialised industry exists in Western Australia to 

supply sticks for use in the lobster-fishing and vegetable-

growing industries (Peter White, pers. comm. 2012). 

Although other myrtaceous species may be used, such as 

Kunzea sp., sticks derived from natural stands of M. viminea 

are preferred due to their greater durability. It is believed that 

lobsters enter pots made from natural materials more readily 

than they do pots made from synthetic substances. In recent 

years, about 1.2 million M. viminea sticks/year have been 

used in making lobster pots. Additionally, large numbers of 

M. viminea stakes are used each year in the vegetable-grow-

ing areas of the Gascoyne region for supporting climbing 

beans. Presently, these markets are supplied from natural 

stands but it may be that, in the future, the supply of sticks 

and stakes could be augmented from plantation sources.

Sawn wood

The wood of the broad-leaved paperbarks M. cajuputi, 

M. leucadendra, M. quinquenervia and M. viridiflora has 

yellowish sapwood, merging gradually into pinkish-brown/

red/grey heartwood. It has a high silica content (0.2–1.0%) 

which blunts saws and planes. It is hard, heavy and of 

moderate strength, with wood from native trees giving a 

green density of c. 1,070 kg/m3 and an air-dry density of 

c. 750–800 kg/m3 (Keating and Bolza 1982; Bootle 1983). 

Florida-grown wood of M. quinquenervia has a basic 

specific gravity of 0.49, a density of 1,070 kg/m3 (green), 

640 kg/m3 (air-dry) and 620 kg/m3 (oven-dry) (Huffman 

1981). Collapse is slight, with shrinkage about 3.5% radial 

and 7% tangential (Bootle 1983). Sawn timber tends to 

check and warp but, if carefully seasoned, it is suitable 

for general construction and flooring. Boards are difficult 

to plane and mortice due to interlocking grain but glue 

well and are good for joinery. Boat knees can be cut from 

branches using their natural shape.

Figure 19. Production and marketing Melaleuca poles and piles in Long An province, Vietnam: (A) harvesting 

and loading poles onto a barge for transport to market; and (B) stacks of melaleuca poles at a roadside market




3. U



Vietnam is the main producer of Melaleuca woodchips for 

use in fibreboard production. In 2010, 100,000 t (bone-

dry) of Melaleuca woodchips were exported from Vietnam 

to China, presumably for this purpose. Presently, there are 

well-advanced plans to establish a medium-density fibre-

board (MDF) plant in the Mekong Delta of Vietnam to 

utilise the Melaleuca resource directly (Stephen Midgley, 

pers. comm. 2012).

The ‘kraft’ pulping potentials of 2-year-old paperbark 

wood from Vietnamese plantations were reported by Chen 

and Su (1998, as M. leucadendron). The low pulp yield and 

high chemical consumption were unfavourable pulping 

characteristics but the strength index was adequate and 

bleachability excellent. The authors indicated that older 

trees might have better pulp qualities.


Organic chemicals produced and stored naturally in 

plant tissues are numerous and chemically complex. By 

definition, extractives are the organic chemicals that can 

be removed from plant tissues by the action of water, 

including steam, other inert solvents such as alcohol and 

by mechanically crushing the source materials. The types 

of extractive from selected Melaleuca species that are of 

economic importance or have commercial potential fall 

into two classes: non-volatile (e.g. betaines) extractives and 

volatile (foliar essential oils).

Non-volatile extractives

The foliage of a range of Melaleuca species produces com-

mercial levels (>2% fresh weight) of betaine (Naidu and 

Cameron 1999). Betaines are non-volatile, water-soluble 

compounds and comprise three methylated prolines: 

N-methylproline, trans-4-hydroxy-N-methylproline and 

trans-4-hydroxy-N,N-dimethylproline. They are osmo-

protectants against stress (e.g. unfavourable temperatures

drought, soil salinity) in tolerant plants and on application 

(foliar and seed treatment) to stress-susceptible plants can 

create acquired tolerance. Naidu (2003) believes that the 

use of betaines to increase stress tolerance in Australian 

agricultural crops would stabilise and even increase the 

national income from agriculture.

Glycine betaine, a by-product of the sugar-beet indus-

try, is currently sourced from Finland and a worldwide 

shortage is predicted for this solute. Australian melaleucas 

are a good alternative source of osmoprotectants. Naidu 

(2003) found that M. bracteata, which accumulates a pro-

line analogue, trans-4-hydroxy-N-methyl proline, had the 

greatest potential of the melaleucas tested for commercial 

development, because of its adaptability, vigorous growth 

and high yields. Despite this potential, there have been no 

recent reports of further development of this opportunity.

Research has also shown Melaleuca bark and leaves to 

be a rich source of phenolic extractives (tannins) (Huffman 

1981; Hussein et al. 2007) but no commercial exploitation 

of phenolics from melaleucas for uses such as wood adhe-

sives, leather tanning and as antimicrobial agents has been 


Novel flavonoids have been identified in the leaf waxes, 

seeds and honey of several Melaleuca species (e.g. Courtney 

et al. 1983; Wollenweber et al. 2000; El-Toumy et al. 2001; 

Yao et al. 2004; Yoshimura et al. 2008). Similarly, various trit-

erpenes, some previously undescribed, have been extracted 

from the leaves, bark, wood and seed of various melaleucas 

(e.g. Ahmad et al. 1997; Lee and Chang 1999; Vieira et al. 

2004; Bar et al. 2008). Habila et al. (2010), for example, 

have reported the extraction of a triterpene, betulinic acid, 

from the wood of M. bracteata. They tested this compound, 

which they state is known for its anti-HIV and cytotoxic 

activity against malignant versus non-malignant cancer cell 

lines, and against a number of pathogenic organisms from 

the genera Trichophyton, Candida and Microsporum. They 

found that it had ‘great potential’ as an antifungal drug.

Foliar essential oils

An essential oil is the (usually) hydrophobic liquid contain-

ing the volatile compounds that are found in the oil glands 

or trichomes of a plant. These glands are usually associ-

ated with the leaves, although bark, wood or roots of plants 

may also contain essential oil. The oil is usually obtained 

by steam distillation, although the expressed oil (as in the 

case of citrus peel) can also be used. Essential oils are usu-

ally associated with species in the families Myrtaceae and 

Rutaceae, although they do occur in some other families.

Commercially important oils

Relatively few Melaleuca species have essential oils of com-

mercial interest. One of the first species to be exploited 

commercially for its foliar oil was M. cajuputi subsp. caju-

puti in the Maluku archipelago of Indonesia, probably in 

the first part of the eighteenth century. It was one of the 

first products imported to Europe from South-East Asia 

by the Dutch (Gildemeister and Hoffman 1961, cited in 

Lowry 1973), because of its reputation as a panacea in the 

treatment of all kinds of diseases. Cajuput oil is produced 

currently in South-East Asian countries including Indo-

nesia, Cambodia and Vietnam and annual production 

potentially exceeds 600 t (Doran 1999a, b). This oil is rich in 

1,8-cineole (typically 40–60% of total oil) (Doran 1999a, b; 

Pujiarti et al. 2011), as is medicinal Eucalyptus oil but at 

slightly higher proportions (70% or more). Cajuput oil 

acts as a mild antiseptic and is especially useful for treat-

ing respiratory ailments, but also finds use in a wide 

range of personal-care (e.g. ointments and liniments) and 

3. U



household products (Doran 1999a, b; Lassak and McCa-

rthy 2011). Niaouli oil from the 1,8-cineole-rich form of 

M. quinquenervia (40–80% 1,8-cineole) was, until recently, 

produced in Madagascar from plantations yielding 1.5–2.0 t 

of oil/year. This oil was used for similar purposes to cajuput 

oil (Ramanoelina et al. 2008; Lassak and McCarthy 2011). 

Production of niaouli oil in New Caledonia from natural 

stands of M. quinquenervia (Trilles et al. 1999, 2006) has 

now also ceased after many years of exploitation, although 

there is new interest in producing this oil type in Vietnam 

(Le Dinh Kha, pers. comm. 2012).

The basis for the commercial interest in, and develop-

ment of, the Australian tea tree oil industry—utilising 

mainly plantations of M. alternifolia established in north-

ern New South Wales and northern Queensland and 

plantings made outside Australia—can be traced back 

to the 1920s. It was then that the medicinal properties 

of the oil were first studied and reported (Penfold and 

Grant 1925). The terpinen-4-ol-rich oil produced from 

M. alternifolia was found to be a powerful antimicro-

bial agent. It has demonstrated its ability to serve as an 

antiseptic, antifungal, antiviral, antibacterial and anti-

inflammatory agent in multiple studies and is relatively safe 

for topical applications (Southwell and Lowe 1999; RIRDC 

2007; Lassak and McCarthy 2011). It is incorporated into 

many personal-care and household products and is seeing 

increasing use in products designed for agricultural and 

animal-husbandry purposes (Figure 20). Annual produc-

tion in Australia of Australian tea tree oil is estimated to be 

in the order of 400–500 t, worth approximately A$15–20 

million at the farm gate.

The three abovementioned species/chemotypes provide 

the bulk of the commercial production of essential oils 

from the genus at present. In addition, there is sporadic 

interest in the following oils.

Linalool-rich oil is sourced from specific provenances 

of M. ericifolia. Linalool, with its fruity notes, is of value to 

the flavour and fragrance industries and, although it can be 

produced synthetically, there remains a market in aroma-

therapy where natural linalool is preferred (Coppen 1995).

E-nerolidol-rich oil can be extracted from the appro-

priate chemotype of M. quinquenervia. This compound, 

presently sourced from a diminishing world supply of 

cabreuva oil (Erich Lassak, pers. comm. 2007), has an 

established market in perfumery where it is used as a base 

note in many delicate, flowery odour complexes (Bauer 

et al. 1997). Melaleuca quinquenervia was shown to yield 

and coppice well in plantations in northern Queensland 

(Doran et al. 2007) before the recent arrival of myrtle rust 

to Australia (see Chapter 5).

E-methyl cinnamate has been derived from a northern 

Queensland form of M. viridiflora (Hellyer and Lassak 

1968; Brophy and Doran 1996). Methyl cinnamate is a 

colourless, crystalline solid with a fruity, sweet-balsamic 

Figure 20. A sample of the many products that utilise Australian tea tree oil

3. U



odour and its uses include as a flavour enhancer and in 

perfumery (Bauer et al. 1997). A small market exists for 

the natural product, but it can be produced artificially at 

relatively little cost and there is strong competition from 

other natural sources.

Platyphyllol, a b-triketone, is found in M. cajuputi. It 

has been identified as having ultraviolet-blocking attributes 

and insecticidal properties but it is not being produced 

commercially at this time (Yaacob et al. 1989; Brophy and 

Doran 1996; Doran 1999a, b).

Citral-rich oil is extracted from M. teretifolia (Southwell 

et al. 2003, 2005). A small production of this oil has com-

menced from natural stands and plantations in Western 

Australia. The producer claims the oil has perfumery and 

therapeutic properties.

An objective of work undertaken for this book was, if 

possible, to identify other species/chemotypes of melaleuca 

with commercial potential. The results of this work are 

summarised in the ‘Species accounts’ (Chapter 7) and in 

Appendix 1, which provides a quick reference to the oil 

type(s) present in individual species.

Inter- and intra-specific variation

Essential oils from a plant species are not necessarily 

chemically uniform. There can be, and usually is, variation 

in the compounds contained in the oil and their relative 

percentages. For this reason, chemists studying the essen-

tial oils of plants try to examine samples of the oils from 

a number of plants, preferably from many different sites.

Variation in the essential oils may be continuous over a 

geographical region, or it can be quite discrete. This latter 

occurrence leads to the finding of different chemotypes of 

the plant, i.e. plants which, though morphologically the 

same, produce different essential oils. It is possible, because 

of inadequate sampling, to find two different oil composi-

tions within a species (i.e. two chemotypes) when, in fact, 

they just represent the extremes of a continuous variation. 

Examples of both types of variation as they apply to the 

main (M. quinquenervia, M. alternifolia and M. cajuputi) 

and one minor (M. ericifolia) commercial oil-producing 

species are discussed below. The possible presence within 

a species of these types of variation should be borne in 

mind when interpreting the results given in the fol-

lowing sections.

The essential oil of M. ericifolia has been studied for over 

50 years. A 2004 study examined its essential oil content 

over its natural geographical range, which extends from 

coastal regions near Newcastle, New South Wales, in the 

north to Tasmania in the south (Brophy and Doran 2004). 

The study looked particularly at the amount of 1,8-cin-

eole and linalool in the oils and the results are shown in 

Figure 21. Generally, the amount of 1,8-cineole increases 

from Newcastle southwards to Tasmania, and the amount 

of linalool decreases concomitantly. As the essential oil of 

M. ericifolia is important because of its linalool content, it 

is important to source the oil from plants in the north of its 

range. But there is a continuous variation in oil contents so, 

in this case, it is not correct to refer to a cineole chemotype 

or a linalool chemotype.

Melaleuca quinquenervia, in contrast, is a species known 

to contain chemotypes. There are two distinct chemotypes 

of this species; chemotype I contains E-nerolidol as the 

major component (in amounts of up to 95%) of the oil, 

while chemotype II contains major amounts of either 

1,8-cineole or viridiflorol (or both), as well as lesser 

amounts of other terpenes. There is no plant producing 

an oil containing significant amounts of all three oils 

(E-nerolidol, 1,8-cineole and viridiflorol). Viridiflorol 

production is catalysed by terpene synthase enzymes. The 

genes coding for these enzymes are present in the genome 

of all plants of the species, but are expressed only in the vir-

idiflorol chemotype (Padovan et al. 2010). The Australian 

distribution of the two chemotypes has been mapped and 

is shown in Figure 22 (Ireland et al. 2002). The chemotype 

containing major amounts of 1,8-cineole is the basis of the 

niaouli oil industry.

Melaleuca alternifolia exists in several chemical forms 

(chemotypes), although among them there are only three 

principal forms (Butcher et al. 1994; Homer et al. 2000). 

These three chemotypes contain terpinen-4-ol (up to 50%), 

the chemotype on which the tea tree oil industry is based, 

1,8-cineole (up to 60%) and terpinolene (up to 50%). Pro-

duction of the oils of these three chemotypes is controlled 

by three different enzymes (Keszei et al. 2010a, b). The 

1,8-cineole chemotype is not used commercially, and the 

oil presents a similar oil profile to a eucalyptus or niaouli 

oil. This particular type of oil is very common in species of 

Melaleuca (see Appendix 1). The terpinolene chemotype 

found in M. alternifolia (Southwell et al. 1992) also occurs 

in M. trichostachya (Brophy 1999).

Melaleuca cajuputi subsp. cajuputi, the basis of the 

cajuput oil industry in South-East Asia, contains up to 

approximately 60% of 1,8-cineole, together with lesser 

amounts (approximately 10%) of limonene, a-terpineol 

and viridiflorene, and spathulenol (up to 30% in some 

cases). There are, however, a few isolated cases of this spe-

cies, from northern Western Australia, producing an oil 

containing large amounts of E-nerolidol and virtually no 

1,8-cineole (J.J. Brophy et al., unpublished data).

Species by oil type

With 290 species in the genus Melaleuca, it is not sur-

prising that their leaf oils have much variation, resulting 

in many different types of oils. In this short section, we 

will review this variation and show what a wide range of 

chemicals is contained in Melaleuca leaf oils. The full data 

from the analyses are provided on the internet, accessible 


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