Their botany, essential oils and uses

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Species producing aromatic (in the chemical sense) oils

So far, only five species (M. bracteata, M. halmaturorum, 

M. leucadendra, M. squamophloia and M. viridiflora) pro-

duce chemotypes whose oils contain a preponderance of 

aromatic chemicals. Melaleuca bracteata gives four chemo-

types in which methyl eugenol, E-methyl isoeugenol, 

elemicin and E-isoelemicin are the principal components 

of the oils. In a large collection survey in southern and 

central Queensland, several collections (from Rolleston) 

did not contain any aromatic components but were com-

posed entirely of terpenoid components (Masunga 1998). 

Melaleuca squamophloia, a species with a limited distri-

bution, also produces oils containing either elemicin or 

E-isoelemicin as the principal component (Brophy et al. 

1999). Melaleuca leucadendra from the eastern part of its 

range produces oil in which the principal components are 

either methyl eugenol or E-methyl isoeugenol. The methyl 

Figure 21. Variation in the proportions of (A) 1,8-cineole and (B) linalool (% of total oils) in the essential oil of 

Melaleuca ericifolia with latitude of occurrence (derived from Brophy and Doran 2004)























1,8-cineole content (% of total oils)

Linalool content (% of total oils)

Latitude (°S)






















Latitude (°S)



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eugenol chemotype bred true, while the methyl isoeugenol 

chemotype produced these two compounds in an approxi-

mate ratio of 3:1 (Brophy and Lassak 1988). The mix of 

aromatic chemotypes occurs from Flying Fox Creek in the 

Northern Territory eastward to Queensland. Westward of 

Flying Fox Creek the oil is entirely terpenoid in content 

with no aromatic compounds present (Brophy 1999).

Melaleuca halmaturorum produces an oil which, 

although mainly terpenoid, contains about 30% of 

2,4,6-trimethoxy-1-isobutyrophenone and small amounts 

of other aromatic ketones (J.J. Brophy et al., unpublished 

data). Melaleuca viridiflora has two chemotypes, one of 

which has three terpene variants, while the other chemo-

type contains E-methyl cinnamate (82%) as its principal 

component. The remainder of this oil is composed of 

2,4,6-trimethoxy-1-isobutyrophenone (5%), a monoter-

pene, E-b-ocimene (12%), and other terpenoid compounds 

(Hellyer and Lassak 1968; Brophy 1999).

Related to aromatic compounds are b-di-or b-tri-

ketones, and several species produce these in significant 

amounts in their leaf oils. Melaleuca triumphalis contains a 

novel b-diketone, triumphalone, and its thermal rearrange-

ment product, as by far the major component of its leaf 

oil (Brophy et al. 2006a). Melaleuca nanophylla contains 

a b-triketone, flavesone (44%), as a principal component 

of its leaf oil, while M. deanei contains a homologous 

b-triketone, leptospermone, in small amounts.

Species producing lemon­scented oils

There are only four Melaleuca species known to produce 

lemon-scented oils, namely M. alsophila, M. citrolens, 

M. stipitata and M. teretifolia. Melaleuca alsophila exists in 

several chemical forms, but one form contains geranial as a 

major component. In this oil there is a significant amount 

of terpinen-4-ol.

Melaleuca citrolens, so named after the lemon scent 

of the crushed leaves, exists in six chemical forms, three 

of which have this lemon scent. These lemon-scented 

forms contain (a) citronellal, as well as 1,8-cineole and 

isopulegol, (b) 1,8-cineole, neral, geranial and citronellic 

acid in significant amounts, and (c) neral, geranial and 

methyl cinnamate. There is also a form that contains cit-

ronellol (21–47%) and methyl citronellate (9–31%) which 

has a pleasant fruity (but not necessarily lemon-scented) 

odour. Melaleuca stipitata also contains neral and geranial 

(totalling over 40%) as well as terpinen-4-ol (10%) in its 

lemon-scented leaf oil, while one chemotype of M. tereti-

folia contains neral (29%) and geranial (39%) as principal 

components of its oil.

Species producing oils with significant amounts of 


So far, about 10 species have been found to produce leaf 

oils containing significant amounts of linalool. They can 

contain up to 55% of linalool in their oils, sometimes 

within a particular chemotype of that species. The main 

species is M. ericifolia which, in the northern extent of is 

range, produces an oil containing up to 55% of linalool 

and, more importantly, in yields of 1–2%, based on fresh 

leaf. In the other part of its range, its oil contains 1,8-cin-

eole as the major component (Brophy and Doran 2004, 

and references therein).

Other species containing linalool in significant 

amounts are: M. bisulcata, 55% (0.5% yield); M. depressa, 

37% (0.3% yield); M. exuvia, 16–26% (2% yield); 

M. hamata, 28–34% (0.6–1.0% yield); M. parviceps, 41% 

(0.2% yield); M. spicigera, 39% (0.1% yield); M. systena, 

30% (0.2% yield); and M. tuberculata subsp. tuberculata, 

57% (0.4% yield)—all yields are based on fresh weight of 

leaf. For any of these species to be useful commercially, 

they would have to produce the oil at reasonable concen-

trations in the leaves (say >1%, weight for weight [w/w] 

fresh weight), have a high percentage of linalool (say 50% 

and above) in their oils and produce high yields of leafy 

biomass from which to extract the oil. These constraints 

rule out most of the above species except M. ericifolia. It 

is probable that, in most of them, examination of more 

Figure 22. Chemotypes of Melaleuca quinquen­

ervia in Australia (Source: Ireland et al. 2002)


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samples would show a range of linalool concentrations 

and the existence of chemotypes within the species, so 

some might be potentially useful.

Species producing oils with significant amounts of 


Melaleuca alternifolia, and to a minor extent M. linariifolia 

and M. dissitiflora, are used commercially for the pro-

duction of Australian tea tree oil because of their high 

percentage of terpinen-4-ol and good oil yield. Several 

other species also produce terpinen-4-ol oils: M. alsophila, 

15–28% (0.1–0.3% yield); M. arcana, 23–31% (0.6–1.0% 

yield); M. calcicola, 33% (0.3% yield); M. concreta, 35% 

(1–2% yield); M. exuvia, 22–28% (2.0–2.3% yield); 

M. foliolosa, 23–40% (<0.1% yield); M. halophila, 44% 

(1.7% yield); M. hamata, 24–42% (0.7–2.0% yield); 

M. nodosa, 18–20% (0.8–1.3% yield); M. ochroma, 44% 

(0.6% yield); and M. uncinata, 27–31% (0.3–0.5% yield)—

all yields being based on fresh weight of leaf.

As with the species rich in linalool mentioned above, 

there would have to be a significant reason to consider 

using these species to produce a tea tree oil. A reason could 

be that the species grows in saline soils, e.g. M. hamata, 

or contains other useful components, e.g. M. alsophila 

(12–19% geranial) and M. exuvia (16–26% linalool).

Groundbreaking work on gene control of terpene 

biosynthesis in melaleucas

Over the past decade, there has been a revolution in under-

standing the genes that control the production of essential 

oils. Researchers at the Australian National University 

(ANU) have been using new technologies developed 

originally in the family Lamiaceae, and especially in mint, 

to study the genes controlling both the profile and quantity 

of essential oils in M. alternifolia. The primary objective 

of this work is to improve efficiencies in the breeding of 

M. alternifolia for better oil quality and greater in-leaf 

oil concentrations (Keszei et al. 2010b). The latter has a 

direct influence on off-paddock yields and the economics 

of production in this commercially important essential 

oil–producing species (Zhang et al. 2011).

Several conclusions can be drawn from the ANU work 

on the genes controlling terpene synthesis in M. alternifo-

lia that might be broadly applicable throughout the genus. 

Six chemotypes described previously (e.g. Butcher et al. 

1994; Homer et al. 2000), and one additional intermediate 

chemotype, were identified from a reanalysis of existing 

chemical data on the composition of M. alternifolia leaf 

oils. It was confirmed that, as suggested by the chemotypes 

present, as few as three terpene synthase genes produce 

most of the monoterpenoid compounds in M. alternifolia 


Keszei et al. (2010b) found that the gene that makes the 

commercially important compound, terpinen-4-ol, likely 

arose from a chance gene duplication event to an existing 

gene that made 1,8-cineole, followed by a small number of 

mutations. Thus, oil quality (high proportions of terpinen-

4-ol accompanied by low proportions of 1,8-cineole) in 

this species, as demanded by industry, is based on a very 

small number of genetic variants. These genes have been 

characterised, thus allowing screening of seedlings at an 

early age to indicate the chemotype of the mature plant. 

The oil profiles of other species of Melaleuca (e.g. M. quin-

quenervia) are produced similarly (Padovan et al. 2010).

In contrast, the yield of oil in M. alternifolia is deter-

mined by the flux of precursor metabolites that are made 

available for the terpene synthase enzymes. These precur-

sors are produced by a complex series of enzymes in the 

plant cell and, in high-yielding plants, nearly all of these 

are up-regulated (Webb et al. 2013). Ongoing work aims to 

identify the genetic variants that are associated significantly 

with foliar oil concentration, raising the exciting possibility 

of being able to efficiently screen plants at a young age for 

their oil-producing capacity (Külheim et al. 2011).

Readers are directed to texts such as Sell (2010) for 

general information on basic biosynthetic pathways for 

terpenoid compounds in plants and to Southwell and Lowe 

(1999) for information specific to Melaleuca oil biogenesis.



There are many texts available on the propagation of Australian Myrtaceae, including 

Melaleuca species, and readers embarking on a major propagating and planting of 

melaleucas are directed to these for detailed information. Available texts include Doran 

(1990, 1997); Wrigley and Fagg (1993, 2007) and Venning (1988).

Propagation by seed

Mass propagation of melaleucas is usually by seed, which germinate readily in moist, 

warm conditions with no pretreatment. Seed should be sown under shade (optimum 

temperature for germination is 25–30 °C) on a free-draining and sterilised medium and 

covered very sparingly with inert material (e.g. sand). Germination should be complete 

after 15 days and then shade can be reduced. After germination, the tiny seedlings 

can be slow to develop at first, presumably while the roots establish. Once underway, 

however, they grow quickly and the 3–6 months it takes for seedlings to reach plantable 

size is similar to other fast-growing species such as eucalypts.

Young seedlings are easily damaged by overhead water-

ing or rain, or may be killed if the sowing mix dries. 

Growers in Vietnam have adopted the ‘bog’ technique of 

watering to avoid these problems in propagating M. caju-

puti (Figure 23). This involves standing the base of the 

germination tray permanently in water so that moisture 

soaks up to the surface which is constantly moist but not 

flooded. Seed is sown evenly over the surface at a density 

of about 7,000 viable seeds/m2. An inflated plastic bag 

is fitted over the germination tray to maintain a moist 

environment. Once the seedlings are sturdy enough 

to withstand overhead watering (c. 4 weeks), the con-

tainer is removed from the water and handled normally. 

The risk of fungal disease is high, so good hygiene is 


Open-rooted seedlings are sometimes used in estab-

lishment of M. alternifolia plantations in northern 

Queensland. Successful establishment of open-rooted 

seedlings is very dependent on the weather at planting 

time and/or the availability of irrigation. Container-grown 

seedlings, although more expensive to produce than 

open-rooted seedlings, suffer much less planting shock 

and are less susceptible to the vagaries of the weather 

(Colton et al. 2000).

There are two ways of producing container-grown seed-

lings commonly applied in the propagation of melaleucas: 


Propagation, silviculture


and management


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ropagation, silvicultur

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(1) the two-stage system where seeds are first sown into 

germination trays or germination beds and the seedlings 

later transplanted (an operation called pricking out); or 

(2) the direct-to-container system where seeds (usually an 

average of three per container) are sown directly into indi-

vidual containers and thinned down to one per container 

after germination is completed.

In the two-stage system, seedlings are transplanted 

from the germination trays or beds at the second leaf-pair 

stage (usually 2–3 cm tall at 4–8 weeks after sowing) to 

containers (commonly tubes, bags or pots of about 550 cm3 

filled volume, e.g. tubes of 65 mm diameter and 160 mm 

depth) filled with sterilised potting mix (e.g. 1:1:1 coarse 

river sand, perlite and cocopeat with the addition of a 

slow-release fertiliser). Extreme care must be taken during 

transplanting not to ‘J’-root (bend roots upward in a too-

shallow planting hole) seedlings as this will cause retarded 

growth and instability of the seedling after planting. Shade 

cover is needed for the first week after transplanting after 

which time plants should be fully exposed. This technique 

is usually applied when only a relatively small number 

of plants are required and/or seed is in short supply and 

efficient capture of all available seedlings is a requirement. 

Where very large numbers of seedlings are required, as 

in the establishment of M. alternifolia plantations for oil 

production with stocking levels commonly in the order of 

30,000 plants/ha, the direct-to-container system is widely 

applied. Cell-type trays of small individual cell volume 

(c. 20 cm3) (e.g. ‘speedling’ trays) are commonly used 

in this system. A relatively sophisticated nursery infra-

structure, including potting mix and sowing equipment, 

plastic igloos or glasshouses, shadehouses and automated 

watering systems, is usually employed to produce high-

quality planting stock at competitive prices for mechanical 

planting. Seedlings are routinely topped at about 15 cm to 

stop them becoming too tall and spindly and to encourage 

a woody stem. Nursery duration under this system is in the 

order of 12–20 weeks.

Melaleucas form symbiotic mycorrhizal associa-

tions between the roots and various fungi. The roots of 

M. quinquenervia trees growing on stream banks, or in 

fresh or brackish waters in swamps and seepage areas of 

New South Wales, Australia, were found to possess both 

vesicular-arbuscular (VA) mycorrhizas and ectomycorrhi-

zas (Khan 1993). Nurseries growing melaleucas, especially 

where the soils are deficient in phosphorus, should attempt 

to introduce appropriate mycorrhizas to the nursery soil. 

Various delivery systems, including soil, spores, sporocarps 

and vegetative mycelium, are described by Brundrett et al. 

(1996) and Doran (1997).

Vegetative propagation

Many melaleucas can be propagated vegetatively from 

stem cuttings (Figure 24) and grafts (Wrigley and Fagg 

1993) and some have been successfully tissue cultured 

(e.g. M. alternifolia; de Oliveira et al. 2010). To ensure the 

genetic integrity of cultivars, it is essential that they be 

propagated vegetatively.

Figure 23. Melaleuca propagation in Vietnam using the ‘bog’ technique for germinating the 

fine seeds

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ropagation, silvicultur

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Prastyono et al. (2011) highlighted the potential of 

clones in improving oil yields and qualities and, in turn, 

the financial returns to producers of essential oil from 

M. alternifolia plantations. Readers interested in the mass 

vegetative propagation of melaleucas are directed to Chap-

ter 22 in Eldridge et al. (1993) and Chapter 11 in Evans and 

Turnbull (2004). Although mass vegetative propagation 

of tropical eucalypts is the focus of these detailed descrip-

tions, the methods are directly transferable to the related 

genus Melaleuca.

The same principles used in mass vegetative propagation 

can be applied on a much smaller scale. Readers interested 

in the small-scale vegetative propagation of melaleuca cul-

tivars are directed to the treatments by Wrigley and Fagg 

(1993, 2007).

Silviculture and 


Melaleucas are used for a range of landcare, wood and 

non-wood purposes. The silvicultural system adopted will 

depend very much on the end use of the planting, although 

it is clear from the lack of literature on the subject that little 

is known about optimal stand establishment, tending and 

management systems for melaleucas.

Plantations for wood production

Most interest in growing melaleucas for wood production 

is in the tropics on difficult sites for tree growth where the 

adaptive traits of the melaleucas give them a competitive 

advantage over other, higher value tree crops. It is mainly 

the broad-leaved species of the M. leucadendra complex, 

such as M. cajuputi, M. leucadendra and M. quinquen-

ervia, that are grown for this purpose in places such as 

the Mekong Delta of Vietnam. An important advantage of 

the broad-leaved melaleucas over other tree crops under 

cultivation in this harsh environment for tree growth is 

that they can be established successfully without expensive 

and environmentally damaging soil mounding. Mounding 

is required to cultivate alternative species and this exposes 

the acid-sulfate soils. Species of the M. leucadendra com-

plex are able to survive a fluctuating watertable, including 

prolonged seasonal inundation and severe acidity. Other 

important advantages in this environment are abilities to 

withstand strong weed competition and dry-season fire.

Typically, these species are grown in plantations on 

relatively short coppice rotations that maximise the pro-

duction of small-size logs suitable for posts, piles, poles and 

fuelwood. Conventional plantation spacings, such as those 

used in trial plantings in Queensland, Australia (1.5 × 3 m 

and 2 × 3 m; Ryan and Bell 1989), Thailand (2 × 2 m; 

Pinyopusarerk 1989), Vietnam (1.5 × 2 m and 2 × 2 m; 

Hoang Chuong et al. 1996) and Florida, USA (1 × 1 m; 

Geary 1988), appear appropriate for these end uses. Wider 

spacings (e.g. 3 × 3 m up to 6 × 6 m) might be employed 

where agroforestry is being practised or on sites where very 

poor soils are being reforested (Geary 1988).

Practices that include good site preparation, fertilisation 

when required and intensive weed control pay dividends 

in the cultivation of melaleucas, as with other tree crops 

like eucalypts. For example, intensive site preparation by 

ploughing to a depth of 20 cm, addition of a nitrogen/

phorphorus/potassium (NPK) fertiliser and manual tend-

ing have been found to be beneficial to establishment and 

early growth of Melaleuca plantations in the Mekong Delta 

region (Simpson 1995). Although pruning is not usu-

ally applied in Melaleuca plantations, form pruning has 

been advocated for garden specimens of M. leucadendra 

(Hearne 1975).

Reported growth rates are reasonable without being 

exceptional, even on good sites. For example, M. quin-

quenervia trees in Hawaiian plantations on good sites 

average 18 m in height and 50 cm in diameter at 40 years 

(NAS 1983). Annual increments in height of 1–2 m and in 

basal diameter of 1–3 cm are typical of young plantations 

of the broad-leaved melaleucas over a wide range of site 

Figure 24. Stem cuttings of Melaleuca alternifolia 

displaying excellent rooting characteristics


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types (Morton 1966; Lamb 1975; Ryan and Bell 1989; P.A. 

Ryan and R.E. Bell, unpublished report, 1991; Gwaze 1989; 

Pinyopusarerk 1989; Sun and Dickinson 1995; Hoang 

Chuong et al. 1996). Rotation lengths as short as 3–5 years 

are typical in Vietnam.

Plantations for production of essential oils

The silvicultural systems employed for the production of 

essential oils from plantations fall broadly into two cat-

egories as highlighted in the two case studies given here. 

The first case study is that of M. alternifolia plantations 

in northern New South Wales and northern Queens-

land, Australia, which represents an intensive, high-cost 

but high-return system. The second case study is that of 

M. cajuputi subsp. cajuputi in Java, Indonesia, which is 

a less intensive, lower cost but also lower return system. 

This second case is representative of silvicultural systems 

used in developing countries where Melaleuca planta-

tions must provide a multitude of services for sustainable 

development, such as inter-row cropping, rather than oil 

production alone, as is the case with M. alternifolia in 


Australian tea tree oil

Principal source: Plantations of Melaleuca alternifolia 

(Maiden & Betche) Cheel (Figure 25) are the main 

source of tea tree oil in Australia.

Species description: The mature plant is a shrub or 

tree, 2.5–14 m tall. Its reddish-brown bark is papery, 

peeling in long flakes; adult leaves are alternate, linear, 

10–32 mm long, 0.4–1 mm wide and short-petiolate 

to subsessile, with glabrescent blades and dense oil 

glands, more or less in rows (see the M. alternifolia 

species account [Chapter 7] for more details).

Natural occurrence: The species occurs from the Stan-

thorpe district in Queensland, south and east into New 

South Wales to the Lismore and Grafton areas, with a 

southernmost disjunction near Port Macquarie. It is 

found at elevations ranging from near sea level to 800 m.

Climate: Melaleuca alternifolia occurs in warm sub-

humid climates, with mean maximum temperatures 

of hottest and mean minimum of coldest months of 

25–30 °C and 1–9 °C, respectively; frost incidence, low 

to moderate (up to 50 at high elevation sites); and rainfall 

of 750–1,600 mm per year, with a summer maximum.

Topography and soils: The species is found on 

coastal plains and adjacent ranges, where it grows on 

seasonally inundated swamps and along watercourses. 

It grows in soils that are mainly alluvial silty loams 

while, in Queensland, soils are sandy loams derived 

from granite (soil pH 4.5–5.5).

Essential oils: Six or more chemotypes have been 

identified in the foliar oils of M. alternifolia of which 

only one, a terpinen-4-ol–rich (30–48%) type with 

more than 100 components, qualifies commercially 

as Australian tea tree oil (ISO standard no. 4730; see 

ISO 2004). Leaf oil concentration is in the range of 

3–6% (fresh weight).

Uses: Efficacy, stability, oxidation and toxicity of ter-

pinen-4-ol-rich tea tree oil have been closely studied 

for many years. It is an effective antiseptic, antibac-

terial, antiviral, antifungal and anti-inflammatory 

agent and is used in a wide range of antimicrobials 

and cosmetics. It is also sold as pure oil or in 10–15% 

tea tree oil solutions.

Quality and prices: Contaminant-free oils with ter-

pinen-4-ol levels of 40% or more in combination with 

low levels of 1,8-cineole (i.e. <3%) are demanded by the 

principal markets. Oil prices have fluctuated widely in 

recent years but in 2013 are around A$30/kg, recover-

ing from a low of A$12/kg in 2005.

Production and markets: Total annual world pro-

duction of this oil type is in excess of 600 t (Australia 

c. 400 t; China c. 200 t; and others). The main markets 

are North America and Europe.

Plantations for tea tree oil production: North-

eastern New South Wales and the Atherton Tablelands 

of Queensland are hubs for production of Australian 

tea tree oil from plantations totalling around 3,000 ha. 

A typical Australian plantation will be established on 

weed-free, level ground at a stocking rate of 30,000–

35,000 plants/ha at row spacings that suit available 

machinery. Row spacing of 1 m and 30 cm between 

plants within rows is commonly applied. Managing 

weeds, insect pests/diseases and crop nutrition, com-

bined with use of carefully developed, higher yielding 

seed lines, are paramount to optimising production.

Harvesting, distillation and oil storage: Mechanical 

harvesting is used in Australian plantations, with the 

first harvest taking place at 18 months and annually 

thereafter. The best oil yields are in spring and sum-

mer. Steam distillation is used to extract the foliar 


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oils. Typical distillation times are 1.5–2 hours after 

condensate starts to flow. Oil should be stored in cool, 

dark, dry, air-free conditions to minimise the rate of 


Yields: Oil yield is determined by three components: 

yield of biomass harvested; proportion of leaf in the 

total biomass; and oil concentration in the leaves. 

Typically, the first harvest of 18-month-old seedlings 

will give 50%, second harvest of 12-month-old coppice 

75% and third harvest of 12-month-old coppice 100% 

of the mature plantation yield. There is wide disparity 

between growers in oil yields achieved in practice 

due to the many interacting factors involved. Overall, 

the average yield from mature coppice plantations in 

Australia using unselected seed lines is an estimated 

150 kg/ha. Selected seed lines now available from an 

Australian industry breeding program have yielded 

about 270 kg/ha and further substantial increases are 

anticipated through breeding.

Further reading: Southwell and Lowe (1999); Colton 

et al. (2000); Davis (2003); ISO (2004); Doran et al. 

(2006); RIRDC (2007).







Figure 25. Steps in the production of Australian tea tree oil from Melaleuca alternifolia: (A) seedlings grown in 

cell-type trays to produce plants well suited to mechanical planting; (B) mechanical planting into a cultivated, 

weed-free, drained area; (C) newly planted seedlings being irrigated at establishment; (D) a plantation ready for 

harvest; (E) mechanical harvesting into bins; and (F) oil separators in a modern distillery


4. P

ropagation, silvicultur

e and management

Indonesian cajuput oil

Principal source: Plantations of Melaleuca cajuputi 

Powell subsp. cajuputi (Figure 26) are the main source 

of this oil in Indonesia.

Species description: The mature plant is a shrub or 

typically an erect tree, (2–)25(–46 m) tall. Its bark is 

grey to white and papery; adult leaves are alternate, 

mainly narrowly elliptic, 40–140 mm long, 7–26 

mm wide and petiolate, with glabrescent blades 

but silky-hairy on the branchlets and silvery new 

growth, and moderately dense, obscure oil glands 

(see the M. cajuputi species account [Chapter 7] for 

more details).

Natural occurrence: The subspecies occurs in Indo-

nesia (islands of Buru, Seram, Ambon, Tanimbar in 

Maluku province and West Timor) and Australia (Top 

End of the Northern Territory and north-western 

Western Australia). It is found at elevations ranging 

from near sea level to 400 m.

Figure 26. Steps in the production of Indonesian cajuput oil from Melaleuca cajuputi subsp. cajuputi planta-

tions in Java: (A) seedlings grown in polyethylene bags; (B) plantation in Central Java; (C) leafy branches 

delivered to a distillery; (D) four of the eight 1-t capacity pots in a cajuput oil distillery at Gundih; (E) a portion 

of the dry, spent biomass being bundled for fuelling the distillery boiler; and (F) oil separators in a distillery run 

by Perum Perhutani (Forestry Department)







4. P

ropagation, silvicultur

e and management


Climate: Melaleuca cajuputi subsp. cajuputi occurs 

in hot, humid climates, with mean maximum tem-

peratures of hottest and mean minimum of coldest 

months of 31–33 °C and 17–22 °C, respectively; frost 

free; and rainfall of 600–4,000 mm/year, monsoonal 

with up to an 8-month dry season.

Topography and soils: The subspecies is found mainly 

on low swampy coastal plains but, in Maluku, mostly 

pure stands extend inland on infertile gravelly ridges. 

Soils are often highly organic alluvial clays of poor 

drainage and low fertility.

Essential oils: There is wide variation in the chemi-

cal composition of cajuput oil. The commercial oil 

usually contains substantial amounts of 1,8-cineole 

(c. 40–60%). Leaf oil concentration is in the range of 

0.4–1.2% (fresh weight).

Uses: Cajuput oil is classified as non-toxic and non-

sensitising. It is a common household medicine 

throughout South-East Asia and is used internally for 

treatment of coughs and colds and externally for relief 

of pain, often in the form of ointments and liniments. 

The oil is useful in treating roundworm and infections 

of the genito-urinary system. It is used as a fragrance 

and freshening agent in soaps, cosmetics, detergents 

and perfumes.

Quality and prices: Contaminant- and adulterant-free 

oils with 1,8-cineole levels of 55–65% are preferred 

by the principal markets. Oil prices at Indonesian 

Government distilleries in 2013 are around A$15/kg.

Production and markets: Total world production 

of 1,8-cineole-rich cajuput oil is estimated to be 

c. 600 t/year, with most oil produced in Indonesia 

(300 t from plantations and 90 t from natural stands) 

and Vietnam (100 t from natural stands). The main 

markets are in South-East Asia.

Plantations for cajuput oil production: The main 

source of oil in Indonesia is from 20,000 ha of planta-

tion established on degraded lands on the main island 

of Java. Plantations are established at an average stock-

ing rate of 2,000 seedlings/ha. Since 2002, genetically 

improved seed from a government breeding program 

has been deployed to improve oil yields and quality. 

Plantations are intercropped with cassava, maize 

and peanuts and participating farmers are required 

to weed the cajuput trees when weeding their crops. 

There are no major pests or diseases and fertiliser is 

not routinely applied.

Harvesting, distillation and oil storage: At 4 years of 

age, plants are pollarded at 1.1 m above ground during 

the first harvest of essential oils. Thereafter, plants are 

visited annually, when coppice shoots of greater than 

1 cm diameter are selectively harvested and leaves 

and twigs stripped into hessian bags for transport to 

the distillery. Peak production in Java is from June to 

October when oil yields are highest. Steam distillation 

is used to extract the foliar oils. Distillation time is 

usually 4 hours. Oil should be stored in cool, dark, dry, 

air-free conditions to minimise the rate of oxidation.

Yields: A plantation of 1 ha established using unim-

proved seed produces about 7.5 t of cajuput leaves 

annually which in turn produces about 60–65 kg of 

oil. Through use of the improved seed available since 

2002, future yields are expected to improve by more 

than 20%.

Author: Dr Anto Rimbawanto, Centre of Forest 

Biotechnology and Tree Improvement (CFBTI), Yog-

yakarta 55582, Indonesia.

Further reading: Doran (1999a, b); Susanto et al. 

(2003, 2010).


Pests and diseases

A wide range of insects causing damage to leaves, stems and roots of various Melaleuca 

species—including suckers (e.g. bugs, psyllids, froghoppers, scales, galls and thrips) 

and chewing pests (e.g. sawflies, caterpillars, beetles and borers)—has been described 

by Elliot and Jones (1982, 1983), Elliot et al. (1998) and Jones and Elliot (1986), who 

also give methods of control.

Over 400 herbivorous insects were found in association with M. quinquenervia and 

its close allies in Australia (Balciunas et al. 1993a, b; Burrows et al. 1994) but damage 

was reported as localised. Coreid bugs attacked the growing tips of coppice growth 

of M. quinquenervia in trials in northern Queensland, reducing yields of essential oil 

and requiring application of insecticidal sprays (Doran et al. 2007). This species was 

reported as suffering slight damage from sawflies (Marcar et al. 1995) and possess-

ing heartwood that lacked resistance to damage by termites, marine borers and fungi 

(Bultman et al. 1983). Damage to M. leucadendra by grasshoppers and leaf-rolling 

caterpillars can be severe during the dry season in northern Australia (Hearne 1975).

Of the more than 100 insect species identified in native 

stands and plantations of M. alternifolia in Australia, 

five have emerged as significant pests in commercial 

essential oil–producing plantations. They are pyrgo bee-

tles (Paropsisterna tigrina), psyllids (Trioza spp.), mites 

(Eriophyoid spp.), pasture scarabs (Diphucephala lineata) 

and leafhoppers (including Erythroneura spp.) (Colton et 

al. 2000). All eat flush new leaves or suck their sap and 

can cause extensive damage. The sap-sucking leafhop-

pers also attract ants which in turn promote infestation 

by black sooty mould. Economic losses through attack of 

M. alternifolia plantations by African black beetle, mole 

crickets, cutworms and a wide range of other minor insect 

pests have also been reported.

Myrtaceae tip blight and leaf spots can attack mela-

leucas (Jones and Elliot 1986) and powdery mildew and 

grey mould (Botrytris sp.) can develop on cultivated, orna-

mental melaleucas, especially when dry-region species are 

cultivated in humid, subtropical climates.

An introduced disease of Australian plants of the 

family Myrtaceae, Puccinia psidii sensu lato (synonym 

Uredo rangelii), or myrtle rust as it is commonly called in 

Australia, was first observed on the central coast of New 

South Wales in April 2010 (Morin et al. 2012). This exotic 


Pests, diseases and


other limitations

5. P

ests, diseases and other limitations


pathogen (native to South America) has now spread from 

Victoria to the Daintree River, north of Cairns in northern 

Queensland. Myrtle rust is a form of guava/eucalyptus 

rust which has had severe impacts on eucalypt plantations 

in Brazil and has spread to other parts of the Americas 

(South, Central and North), China and Japan. Melaleuca 

quinquenervia, an invasive pest in the Florida Everglades, is 

highly susceptible to guava rust in Florida and Hawaii (see 

following section on ‘Weediness/biological control’) and 

also highly susceptible to the rust in Australia. This disease 

has so far been observed on 107 host species in 30 genera, 

including Angophora, Asteromyrtus, Backhousia, Eucalyp-

tus, Leptospermum and Melaleuca (Carnegie and Lidbetter 

2012). There are expectations that many more species will 

be found susceptible and this is causing much concern. The 

young leaves and shoots of seedlings, the outer growing 

tips of the crowns of saplings and, in some cases, adult 

trees (e.g. M. quinquenervia) and coppice from stumps or 

damaged trees are most vulnerable to attack by myrtle rust. 

The rust causes spots or lesions on young leaves and shoots 

that spread and develop masses of yellow powdery spores 

(Figure 27). The rust can also infect floral buds and young 

fruit, depending on the host. Infected leaves become curled 

and distorted and severe infection can kill shoots, causing 

these plants to become stunted after repeated infections. 

In the worst cases, death of the whole plant can occur after 

repeated destruction of new growth.

Melaleuca alternifolia in plantations in northern New 

South Wales that at first appeared to be resisting the spread 

of myrtle rust are now showing signs of greater damage 

with the rust-induced death of flush growth and upper 

stems becoming more common (Peter Entwistle, pers. 

comm. 2012). Other fungal pathogens of M. alternifolia 

plantations include stem blight (Dothiorella sp.), with pink 

disease (Cylindrocladium sp.) that causes leaf drop, char-

coal root disease (Macrophemena phaeseolina or Diplodia 

sp.) and leaf scab (Elsinoe sp.) also causing damage (Colton 

et al. 2000). These authors also reported grey mould (Bot-

rytis cinerea), anthracnose (Colletotrichum sp.), rhizoctonia 

(Rhizoctonia sp.) and damping off (Pythium sp.) to be 

important diseases in nurseries growing M. alternifolia 

seedlings. Some Western Australian melaleucas are prone 

to the rootrot fungus Phytophthora cinnamomi (Wrigley 

and Fagg 1993). Colton et al. (2000) reported that no bac-

terial or viral diseases of economic importance have been 

identified in M. alternifolia plantations.

Other limitations

Weediness/biological control

Melaleuca species can seed profusely and there are 

instances in Australia where they have escaped cultiva-

tion and naturalised to become invasive and troublesome 

weeds, especially where periodic fires provide a suitable 

seedbed. Species that are reported to have naturalised 

include M. armillaris, M. bracteata, M. decussata, M dios-

mifolia, M. ericifolia (per root suckers), M. halmaturorum, 

M. hypericifolia, M. incana, M. lanceolata, M. leucadendra, 

M. linariifolia, M. microphylla, M. nesophila, M. parvista-

minea, M. pentagona, M. quinquenervia, M. styphelioides, 

M. viminalis and M. viminea (Lazarides et al. 1997; Randall 

2002; Richardson et al. 2011; Wiersema and León 2013).

Beyond Australia, M. quinquenervia has become a 

United States federally listed noxious weed in southern 

Florida and is also moderately invasive in the Carib-

bean (Bahamas and Puerto Rico) and Hawaii (Dray et al. 

2006). Melaleuca quinquenervia was first introduced into 

Florida as an ornamental and agroforestry species from 

Australian and exotic sources. Dray et al. (2006) have 

traced the earliest introduction back to 1886 in Sarasota 

County, with the species becoming naturalised in south-

ern Florida during the 1920s and spreading rapidly from 

there. Since its introduction, the tree has invaded more 

than 200,000 ha of Florida wetlands, including portions 

of Everglades National Park (Turner et al. 1998). With 

its prolific seed production, M. quinquenervia rapidly 

invades moist, open habitats, both disturbed and undis-

turbed, and forms dense, impenetrable monocultures. 

Unmanaged stands may have stocking densities of 

7,000–20,000 stems/ha, thus crowding out native vegeta-

tion and wildlife habitats (Geiger 1981; Loope et al. 1994). 

Serbesoff-King (2003) reported that public agencies in 

Florida had spent US$25 million in control efforts between 

1989 and 1999. Serbesoff-King (2003) also gave estimates 

of economic impacts of the invasive Melaleuca populations 

on recreation, tourism, fires, loss of endangered species 

and more. These ranged from US$168 million annually to 

US$2 billion over a period of 20 years. It is currently being 

suppressed using manual, mechanical, herbicidal and bio-

logical control management strategies (Martin et al. 2011).

A classical weed biological control program target-

ing M. quinquenervia in Florida was initiated in the late 

1980s. Surveys in Australia for potential biological control 

agents of M. quinquenervia for possible release in Florida 

revealed several promising insect species (Center 1992; 

Balciunas and Burrows 1993; Balciunas et al. 1993a, b; 

Purcell and Balciunas 1994). One herbivore established 

for biological control of M. quinquenervia in Florida is a 

weevil, Oxyops vitiosa. It was introduced into Florida in 

1997 (Christensen et al. 2011) and prefers to feed on the 

nerolidol chemotype. Another is a psyllid, Boreioglycaspis 

melaleucae, which was released in 2002 and prefers the 

viridiflorol chemotype. Predation of M. quinquenervia 

by these insects eventually results in partial defoliation 

of mature trees, loss of reproductive ability and mortal-

ity of seedlings (Martin et al. 2011; Pratt and Arakelian 

2011). Tipping et al. (2009), in a 5-year study of a cypress 


5. P

ests, diseases and other limitations

pine wetland in the West Everglades invaded by M. quin-

quenervia after a destructive crown fire, reported a 48% 

decline in Melaleuca density over 5 years due to biological 

control agents. Annual mortality ranged from 11% to 25% 

and mean tree height declined by 31%. Rayamajhi et al. 

(2009) found rapid reduction in Melaleuca density and 

canopy cover, attributed to self-thinning accelerated by the 

negative impact of the introduced insect pests, positively 

influenced native plant diversity (two- to fourfold increases 

in plant diversity) and facilitated the partial rehabilitation 

of degraded habitats.

Fungi are also under investigation as potential biological 

control agents of M. quinquenervia in Florida (Rayachhetry 

et al. 1996a, b). Puccinia psidii, as detailed in the previous 

section on ‘Pests and diseases’, is one possibility. In the 

early 2000s, P. psidii was observed on M. quinquenervia 

in Florida (Rayachhetry et al. 2001). It has now joined the 

introduced herbivores as effective biological control agents 

Figure 27. Puccinia psidii sensu lato (synonym Uredo rangelii) (myrtle rust) spores on 

Melaleuca quinquenervia in northern New South Wales: (A) yellow spores on a leafy 

shoot; and (B) a badly deformed and stunt young plant after rust attack of its growing tips




5. P

ests, diseases and other limitations

of M. quinquenervia in Florida although there are resistant 

individuals (Rayamajhi et al. 2010a, b). Regrettably, it has 

been found to also attack some native American species, 

including a threatened species.

Source of allergens

Earlier reports implicating M. quinquenervia in southern 

Florida as the cause of serious allergic reactions and acute 

respiratory problems in humans (Geary 1988) have been 

shown to be false in a detailed medical study involving 

more than 1,000 subjects (Stablein et al. 2002).


Conservation status

An estimated 100 million ha of the Australian landscape have been cleared for agricul-

ture, urban development, mining and other pursuits. In addition to clearing of forests 

and woodlands, drainage and flood mitigation measures, waterlogging from irrigation 

and increased salinity have all adversely affected the extent of natural populations of 

Melaleuca. Australia accounts for 20% of the world’s flora that has been classified as 

‘presumed extinct’ and 15% of the world’s flora that has been recognised as ‘threatened’ 

(Briggs and Leigh 1995). It is somewhat surprising, therefore, to report that apparently 

no species within this large plant genus have been classified as ‘presumed extinct’. 

Wrigley and Fagg (1993) reported that M. arenaria, a species described in 1923 from 

a specimen collected in the Western Australian wheatbelt in an area subject to much 

clearing, was ‘presumed extinct’, but this species is now considered to be a variety of 

the widespread M. tuberculata (see ‘Species accounts’ [Chapter 7]).

Briggs and Leigh (1995) listed 48 Melaleuca taxa (including 

Callistemon) in their compendium of rare and threatened 

Australian plants. Melaleuca kunzeoides, from central 

southern Queensland, M. sciotostyla, from south-western 

Western Australia, and Callistemon sp. 1 (Boulia, L.Pedley 

5297)—now classified within the widespread M. viminalis 

subsp. viminalis—were listed as ‘vulnerable’; with only 

one of these species, M. sciotostyla, protected in reserves 

in 1995. Eighteen species, 15 of which were in reserves or 

National Parks in 1995, were classed as ‘rare’ (Callistemon 

acuminatus [= M. flammea], M. basicephala, M. cheelii, 

M. chisholmii, M. cliffortioides, M. corrugata [= M. fulgens 

subsp. corrugata], M. deanei, M. fissurata, M. flavovirens, 

M. formosa, M. groveana, M. linearifolia, M. pauciflora, 

M. pearsonii, M. pungens, M. pustulata, M. shiressii and 

M. tortifolia); and the remaining taxa were placed in cat-

egory ‘K’. Category ‘K’ is for species known to be limited 

in distribution but whose conservation status cannot be 

reliably determined, either because the species has been 

seldom collected or there is uncertainty about the level of 

threat. The list of rare or threatened Australian melaleucas 

needs to be revised, as many very localised and/or rare 

species have been described since 1995.

Outside Australia, there have been concerns about the 

decline of Melaleuca forests and woodlands of M. cajuputi 

subsp. cumingiana in the wetlands of South-East Asia. 

Clearing and draining of the Melaleuca forests for rice 

production and other crops in places such as the Mekong 

Delta region of Vietnam have led to environmental deg-

radation, loss of biodiversity and social consequences for 

Conservation and




6. Conserv

ation and pr


local peoples (Safford et al. 2009). While not to the extent 

yet of endangering the survival of the species in these 

wetlands, there are, nevertheless, compelling reasons to 

rehabilitate selected areas of these forests and woodlands. 

This has been a priority in Vietnam’s forest policy since 

the mid 1990s.


Opportunities for wider use

Reasonable growth rates in the face of extremely poor 

environmental conditions for plant growth and a broad 

range of uses are among the desirable attributes of the 

Melaleuca species regularly deployed in reforestation, 

land reclamation, amenity and ornamental plantings and 

for production of essential oils. With a predominance 

of species occurring in arid and semi-arid regions, but 

with a range from the humid tropics to cool temperate 

southern Australia and on highly variable soils and topog-

raphy, it is possible to select species that are tolerant of 

a wide range of unfavourable conditions (infertile soils, 

poorly drained sites, continuous and periodic inundation, 

coastal exposure, fire, frost, salinity and both high and 

low soil pH). Uses, depending on species/provenances 

or cultivars, include ornamental and amenity planting, 

essential oils, fuelwood, woodchips, sawn timber, posts, 

poles, rails, brushwood fencing, shade and shelter, honey, 

land reclamation and improvement in biodiversity values. 

In Appendix 2, we have endeavoured to highlight by end 

use, best-bet species for planting/trialling in two broad 

climatic zones: (A) subtemperate and (B) tropical and 


Melaleucas are largely outbreeding, often with herit-

able and highly variable commercial traits (e.g. foliar 

oil concentrations and various growth characteristics, 

including inflorescence shape and flower colour). This 

provides a huge opportunity for the tree breeder, whose 

main task is to exploit this variability through explora-

tion, evaluation, selection and breeding. Nowhere is this 

more so than with the ornamental Melaleuca cultivars 

that after manipulation by controlled pollination, either 

within or between species, must be propagated vegeta-

tively to capture desired characteristics (e.g. inflorescence 

shape and colour). There is also great opportunity for 

selection and breeding to improve oil yields and oil 

qualities in the established essential oil–producing 

species M. alternifolia, M. cajuputi subsp. cajuputi and 

M. quinquenervia. These species all have distinctly dif-

ferent chemical variants of which only one (or two in 

the case of M. quinquenervia) of several types found in 

nature is suitable for commercial exploitation. So it is 

very important to select the provenance(s) within species 

that will reliably provide the required oil as well as the 

ability to grow rapidly and coppice well so that oil yields 

are maximised.

Once the best natural provenances are identified, 

further economic gains can be achieved by selection 

between and within families established in progeny tri-

als and development of clonal or seedling seed orchards 

to provide improved seed. This is well demonstrated by 

a traditional, relatively low-cost, seed-based breeding 

program for M. alternifolia in Australia (Figure 28). This 

program has delivered to industry realised genetic gains 

in oil yield from improvements in foliar oil concentration 

and leaf biomass per ha in one generation of breeding: 

55% from selections within the best natural provenance; 

43% from a culled, broadly based seedling seed orchard; 

and 83% from a clonal seed orchard established by 

stem cuttings from selected individuals within the best 

provenances in a progeny trial (Doran et al. 2006). Even 

greater genetic gains are expected to be realised from the 

second generation of selection and breeding in this spe-

cies. Similar results have been achieved in the breeding 

of M. cajuputi subsp. cajuputi in Indonesia where gains 

in oil yield in excess of 20% are anticipated from the first 

generation of selection and breeding in open-pollinated 

seedling seed orchards (A. Rimbawanto, ‘Indonesian 

cajuput oil’ section in Chapter 4).


High on the list of undesirable traits, particularly when 

introducing melaleucas to a new environment, is the 

potential for their spread from cultivation to become 

noxious weeds. This occurs through distribution of seed by 

wind and water from canopies that hold a store of mature 

fruit, often for many years, awaiting the right conditions to 

stimulate release (e.g. fire) and also root suckering which 

is a feature of some melaleucas with extensive root systems 

(e.g. M. ericifolia, M. viridiflora). The experience with the 

M. quinquenervia invasion of the Florida Everglades is a 

classic example of an inappropriate species introduction 

that has gone horribly wrong, with the aggressive, fast-

growing invader crowding out regeneration of native 

species and destroying wildlife habitat. Thus, extreme 

caution is warranted when introducing a Melaleuca to a 

new environment for the first time, and particularly, it 

seems, in swampy conditions. Another disadvantage is the 

susceptibility of certain of the more tropical species, such 

as M. leucadendra and M. quinquenervia, to fungal attack 

at a young age by the rust, Puccinia psidii sensu lato. Insect 

pests are also an impediment to the successful establish-

ment and growth of some species (e.g. in the cultivation 

of M. alternifolia for essential oil production), requiring 

use of chemical sprays. Despite these disadvantages, there 

will be localities where the genus Melaleuca can provide 

the species-of-choice for the prevailing conditions and 

intended end use.

6. Conserv

ation and pr



Figure 28. Progeny trials (A, B), a young seedling seed orchard (C) and controlled crossing activities (D–F) as 

part of a tree breeding project aimed at improving oil yields in Melaleuca alternifolia in Australia








6. Conserv

ation and pr


Advice is at hand

Prospects for wider exploitation of carefully selected 

germplasm of Melaleuca species appropriate for intended 

end use(s) both within and beyond their zones of natural 

occurrence appear promising. When considering intro-

duction of a Melaleuca species to a location for the first 

time, plant risk analysis procedures should be applied and 

the species rejected if the weediness risk is unacceptable. 

The Australian Tree Seed Centre, CSIRO Plant Industry, 

Canberra, holds seed stocks of a wide range of mainly 

tree-form melaleucas and is a source of both seed and 

information on cultivating species in the genus.

Document Outline

  • Cover
  • Foreword
  • Contents
  • Melaleuca species
  • Melaleuca synonyms
  • Preface
  • 1. Taxonomic history and systematics
    • Historical context
    • Studies based on morphological evidence
    • Incorporating DNA evidence in classification
    • Current and future classification challenges
  • 2. Introduction to the genus Melaleuca
    • General information
      • Family and tribe
      • Botanical name
      • Common names
      • Ploidy
      • Number of species
    • Botanical features
      • Habit and size
      • Bark
      • Foliage
      • Flowers
      • Reproductive biology
      • Timing of flowering
      • Pollination and pollen biology
      • Hybridisation
      • Fruits
      • Seeds
      • Cotyledons
    • Geographical distribution and ecology
      • Natural occurrence and ecology
      • Locations of planted forests
    • Tolerance of difficult conditions
  • 3. Uses
    • Ethnobotanical
    • Ornamental, landcare, honey, bark and wood
      • Ornamental and amenity–horticultural use
      • Land rehabilitation
      • Brushwood fencing and related products
      • Honey
      • Bark
      • Wood
        • Fuelwood
        • Posts, poles, stakes and sticks
        • Sawn wood
        • Woodchips
    • Extractives
      • Non-volatile extractives
      • Foliar essential oils
        • Commercially important oils
        • Inter- and intra-specific variation
        • Species by oil type
        • Groundbreaking work on gene control of terpene biosynthesis in melaleucas
  • 4. Propagation, silviculture and management
    • Propagation
      • Propagation by seed
      • Vegetative propagation
    • Silviculture and management
      • Plantations for wood production
      • Plantations for production of essential oils
      • Australian tea tree oil
      • Indonesian cajuput oil
  • 5. Pests, diseases and other limitations
    • Pests and diseases
    • Other limitations
      • Weediness/biological control
      • Source of allergens
  • 6. Conservation and prospects
    • Conservation status
    • Prospects
      • Opportunities for wider use
      • Caution
      • Advice is at hand

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