Melaleuca
Encyclopedia
Melaleuca is a genus
of plant
s in the myrtle family Myrtaceae
known for its natural soothing and cleansing properties. There are well over 200 recognised species, most of which are endemic to Australia
. A few species occur in Malesia
and 7 species are endemic to New Caledonia
.
The species are shrub
s and tree
s growing (depending on species) to 2 – tall, often with flaky, exfoliating bark
. The leaves
are evergreen
, alternately arranged, ovate to lanceolate, 1 – long and 0.5 – broad, with an entire margin, dark green to grey-green in colour. The flower
s are produced in dense clusters along the stems, each flower with fine small petals and a tight bundle of stamens; flower colour varies from white to pink, red, pale yellow or greenish. The fruit
is a small capsule containing numerous minute seed
s.
Melaleuca is closely related to the genus Callistemon, the main difference between the two is that the stamen
s are generally free in Callistemon but grouped into bundles in Melaleuca. Callistemon was recently placed into Melaleuca.
In the wild, Melaleuca plants are generally found in open forest, woodland or shrubland, particularly along watercourses and the edges of swamps.
The best-accepted common name for Melaleuca is simply melaleuca; however most of the larger species are also known as tea tree, and the smaller types as honey myrtles, while those species in which the bark is shed in flat, flexible sheets are referred to as paperbarks. The Tea tree is presumably named for the brown colouration of many water courses caused by leaves shed from trees of this and similar species (for a famous example see Brown Lake (Stradbroke Island)
). The name "tea tree" is also used for a related genus, Leptospermum
, also in Myrtaceae
.
One well-known melaleuca, Melaleuca alternifolia
, is notable for its essential oil
which is both anti-fungal, and antibiotic
, while safely usable for topical applications. This is produced on a commercial scale, and marketed as Tea Tree Oil
.
In Australia, Melaleuca species are sometimes used as food plants by the larva
e of hepialid
moth
s of the genus Aenetus
including A. ligniveren
. These burrow horizontally into the trunk then vertically down.
Melaleucas are popular garden plants, both in Australia and other tropical areas worldwide. In Hawaii
and the Florida
Everglades
, Melaleuca quinquenervia
(Broad-leaved Paperbark) was introduced in order to help drain low-lying swampy areas. It has since gone on to become a serious invasive species
with potentially very serious consequences being that the plants are highly flammable and spread aggressively. Melaleuca populations have nearly quadrupled in southern Florida over the past decade, as can be noted on IFAS
's SRFer Mapserver
used the leaves traditionally for many medicinal
purposes, including chewing the young leaves to alleviate headache
and for other ailments.
made from Melaleuca alternifolia is a highly effective topical
antibacterial and antifungal, although it may be toxic when ingested internally in large doses or by children. In rare cases, topical products can be absorbed by the skin and result in toxicity.
The oils of Melaleuca can be found in organic
solutions of medication that claims to eliminate wart
s, including the Human papillomavirus
. No scientific evidence proves this claim (reference: "Forces of Nature: Warts No More").
Melaleuca oils are the active ingredient in Burn-Aid, a popular minor burn first aid
treatment (an offshoot of the brandname Band-Aid
).
Melaleuca oils (tea tree oil) is also used in many pet fish remedies (such as Melafix and Bettafix) to treat bacterial and fungal infections. Bettafix is a lighter dilution of tea tree oil while Melafix is a stronger dilution. It is most commonly used to promote fin and tissue regrowth. The remedies are often associated with Betta
fish (Siamese Fighting Fish
) but are also used with other fish.
Melaleuca bark is used to make a natural bio-degradable paper
or papyrus
which is considered by many to be a renewable resource
and therefore much more environmentally friendly
than modern paper farming or deforestation .
was introduced to Florida
in the United States
in the early 20th century to assist in drying out swampy land and as garden plants.
Once widely planted in Florida, it formed dense thickets and displaced native vegetation on 391000 acres (1,582.3 km²) of wet pine flatwoods, sawgrass marshes, and cypress swamps in the southern part of the state. It is prohibited by DEP and listed as a noxious weed by FDACS.
Melaleuca quinquenervia became an invasive species
that raised serious environmental issues in Florida’s Everglades
and damaged the surrounding economy. Agricultural Research Service (ARS) scientists from the Australian Biological Control Laboratory assisted in solving the problem by releasing biological controls in the form of insects that feed on this species. http://www.ars.usda.gov/is/AR/archive/jan10/collections0110.htm These insects are natural predators of this species in Australia and help control the spread of the weed in the U.S.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of plant
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
s in the myrtle family Myrtaceae
Myrtaceae
The Myrtaceae or Myrtle family are a family of dicotyledon plants, placed within the order Myrtales. Myrtle, clove, guava, feijoa, allspice, and eucalyptus belong here. All species are woody, with essential oils, and flower parts in multiples of four or five...
known for its natural soothing and cleansing properties. There are well over 200 recognised species, most of which are endemic to Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
. A few species occur in Malesia
Malesia
Malesia is a biogeographical region straddling the boundaries of the Indomalaya ecozone and Australasia ecozone, and also a phytogeographical floristic region in the Paleotropical Kingdom.-Floristic province:...
and 7 species are endemic to New Caledonia
New Caledonia
New Caledonia is a special collectivity of France located in the southwest Pacific Ocean, east of Australia and about from Metropolitan France. The archipelago, part of the Melanesia subregion, includes the main island of Grande Terre, the Loyalty Islands, the Belep archipelago, the Isle of...
.
The species are shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
s and tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
s growing (depending on species) to 2 – tall, often with flaky, exfoliating bark
Bark
Bark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines and shrubs. Bark refers to all the tissues outside of the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner...
. The leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are evergreen
Evergreen
In botany, an evergreen plant is a plant that has leaves in all seasons. This contrasts with deciduous plants, which completely lose their foliage during the winter or dry season.There are many different kinds of evergreen plants, both trees and shrubs...
, alternately arranged, ovate to lanceolate, 1 – long and 0.5 – broad, with an entire margin, dark green to grey-green in colour. The flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s are produced in dense clusters along the stems, each flower with fine small petals and a tight bundle of stamens; flower colour varies from white to pink, red, pale yellow or greenish. The fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
is a small capsule containing numerous minute seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s.
Melaleuca is closely related to the genus Callistemon, the main difference between the two is that the stamen
Stamen
The stamen is the pollen producing reproductive organ of a flower...
s are generally free in Callistemon but grouped into bundles in Melaleuca. Callistemon was recently placed into Melaleuca.
In the wild, Melaleuca plants are generally found in open forest, woodland or shrubland, particularly along watercourses and the edges of swamps.
The best-accepted common name for Melaleuca is simply melaleuca; however most of the larger species are also known as tea tree, and the smaller types as honey myrtles, while those species in which the bark is shed in flat, flexible sheets are referred to as paperbarks. The Tea tree is presumably named for the brown colouration of many water courses caused by leaves shed from trees of this and similar species (for a famous example see Brown Lake (Stradbroke Island)
Brown Lake (Stradbroke Island)
Brown Lake is a lake on North Stradbroke Island, in Queensland, Australia.Known as a perched lake like other lakes on the sandy islands in the region of South-East Queensland it retains its water due to a layer of leaves lining the lake floor...
). The name "tea tree" is also used for a related genus, Leptospermum
Leptospermum
Leptospermum is a genus of about 80-86 species of plants in the myrtle family Myrtaceae. Most species are endemic to Australia, with the greatest diversity in the south of the continent; but one species extends to New Zealand, another to Malaysia, and L. recurvum is endemic to Malaysia.They...
, also in Myrtaceae
Myrtaceae
The Myrtaceae or Myrtle family are a family of dicotyledon plants, placed within the order Myrtales. Myrtle, clove, guava, feijoa, allspice, and eucalyptus belong here. All species are woody, with essential oils, and flower parts in multiples of four or five...
.
One well-known melaleuca, Melaleuca alternifolia
Melaleuca alternifolia
Melaleuca alternifolia, commonly known as Narrow-leaved Paperbark, Narrow-leaved Tea-tree, Narrow-leaved Ti-tree, or Snow-in-summer, is a species of tree or tall shrub in the plant genus Melaleuca. Native to Australia, it occurs on the north coast and adjacent ranges of New South Wales...
, is notable for its essential oil
Essential oil
An essential oil is a concentrated hydrophobic liquid containing volatile aroma compounds from plants. Essential oils are also known as volatile oils, ethereal oils or aetherolea, or simply as the "oil of" the plant from which they were extracted, such as oil of clove...
which is both anti-fungal, and antibiotic
Antibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
, while safely usable for topical applications. This is produced on a commercial scale, and marketed as Tea Tree Oil
Tea tree oil
Tea tree oil, or melaleuca oil, is a pale yellow colour to nearly clear essential oil with a fresh camphoraceous odor. It is taken from the leaves of the Melaleuca alternifolia, which is native to the northeast coast of New South Wales, Australia...
.
In Australia, Melaleuca species are sometimes used as food plants by the larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e of hepialid
Hepialidae
The Hepialidae is a family of insects in the lepidopteran order. Moths of this family are often referred to as swift moths or ghost moths.-Taxonomy and systematics:...
moth
Moth
A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...
s of the genus Aenetus
Aenetus
Aenetus is a genus of moths of the family Hepialidae. There are 24 described species found in Indonesia, New Guinea, New Caledonia, Australia and New Zealand. Most species have green or blue forewings and reddish hindwings but some are predominantly brown or white...
including A. ligniveren
Aenetus ligniveren
The Common Splendid Ghost Moth is a moth in the Hepialidae family. It is found from southern Queensland to Tasmania....
. These burrow horizontally into the trunk then vertically down.
Melaleucas are popular garden plants, both in Australia and other tropical areas worldwide. In Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
and the Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
Everglades
Everglades
The Everglades are subtropical wetlands in the southern portion of the U.S. state of Florida, comprising the southern half of a large watershed. The system begins near Orlando with the Kissimmee River, which discharges into the vast but shallow Lake Okeechobee...
, Melaleuca quinquenervia
Melaleuca quinquenervia
Melaleuca quinquenervia, commonly known as Niaouli or Broad-leaved paperbark or the Paper Bark Tea Tree, is a small- to medium-sized tree of the allspice family, Myrtaceae. The plant is native to New Caledonia, Papua New Guinea and coastal Eastern Australia, from Botany Bay in New South Wales...
(Broad-leaved Paperbark) was introduced in order to help drain low-lying swampy areas. It has since gone on to become a serious invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
with potentially very serious consequences being that the plants are highly flammable and spread aggressively. Melaleuca populations have nearly quadrupled in southern Florida over the past decade, as can be noted on IFAS
IFAS
IFAS can stand for:* Institute of Food and Agricultural Sciences* Irish Federation of Astronomical Societies* Integrated Fixed Film Activated Sludge System* Islamic Financial Accounting Standards* Independent Financial Advisers...
's SRFer Mapserver
Traditional Aboriginal uses
Australian AboriginesAustralian Aborigines
Australian Aborigines , also called Aboriginal Australians, from the latin ab originem , are people who are indigenous to most of the Australian continentthat is, to mainland Australia and the island of Tasmania...
used the leaves traditionally for many medicinal
Bush medicine
Bush medicine is the term used in Australia by Aboriginal people to describe their traditional medicinal knowledge and practices. The term is often used in conjunction with Bush tucker....
purposes, including chewing the young leaves to alleviate headache
Headache
A headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. The brain tissue itself is not sensitive to pain because it lacks pain receptors. Rather, the pain is caused by disturbance of the...
and for other ailments.
Modern uses
Scientific studies have shown that tea tree oilTea tree oil
Tea tree oil, or melaleuca oil, is a pale yellow colour to nearly clear essential oil with a fresh camphoraceous odor. It is taken from the leaves of the Melaleuca alternifolia, which is native to the northeast coast of New South Wales, Australia...
made from Melaleuca alternifolia is a highly effective topical
Topical
In medicine, a topical medication is applied to body surfaces such as the skin or mucous membranes such as the vagina, anus, throat, eyes and ears.Many topical medications are epicutaneous, meaning that they are applied directly to the skin...
antibacterial and antifungal, although it may be toxic when ingested internally in large doses or by children. In rare cases, topical products can be absorbed by the skin and result in toxicity.
The oils of Melaleuca can be found in organic
Organic food
Organic foods are foods that are produced using methods that do not involve modern synthetic inputs such as synthetic pesticides and chemical fertilizers, do not contain genetically modified organisms, and are not processed using irradiation, industrial solvents, or chemical food additives.For the...
solutions of medication that claims to eliminate wart
Wart
A wart is generally a small, rough growth, typically on a human’s hands or feet but often other locations, that can resemble a cauliflower or a solid blister. They are caused by a viral infection, specifically by human papillomavirus 2 and 7. There are as many as 10 varieties of warts, the most...
s, including the Human papillomavirus
Human papillomavirus
Human papillomavirus is a member of the papillomavirus family of viruses that is capable of infecting humans. Like all papillomaviruses, HPVs establish productive infections only in keratinocytes of the skin or mucous membranes...
. No scientific evidence proves this claim (reference: "Forces of Nature: Warts No More").
Melaleuca oils are the active ingredient in Burn-Aid, a popular minor burn first aid
First aid
First aid is the provision of initial care for an illness or injury. It is usually performed by non-expert, but trained personnel to a sick or injured person until definitive medical treatment can be accessed. Certain self-limiting illnesses or minor injuries may not require further medical care...
treatment (an offshoot of the brandname Band-Aid
Band-Aid
Band-Aid is a brand name for Johnson & Johnson's line of adhesive bandages and related products. It has also become a genericized trademark for any adhesive bandage in Australia, Brazil, Canada, India and the United States....
).
Melaleuca oils (tea tree oil) is also used in many pet fish remedies (such as Melafix and Bettafix) to treat bacterial and fungal infections. Bettafix is a lighter dilution of tea tree oil while Melafix is a stronger dilution. It is most commonly used to promote fin and tissue regrowth. The remedies are often associated with Betta
Betta
Betta is a large genus of small, often colorful, freshwater ray-finned fishes in the gourami family . The type species is B. picta, the spotted betta.By far the best known Betta species, however, is B...
fish (Siamese Fighting Fish
Siamese fighting fish
The Siamese fighting fish , also known as the betta , is a popular species of freshwater aquarium fish. The name of the genus is derived from ikan bettah, taken from a local dialect of Malay...
) but are also used with other fish.
Melaleuca bark is used to make a natural bio-degradable paper
Paper
Paper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....
or papyrus
Papyrus
Papyrus is a thick paper-like material produced from the pith of the papyrus plant, Cyperus papyrus, a wetland sedge that was once abundant in the Nile Delta of Egypt....
which is considered by many to be a renewable resource
Renewable resource
A renewable resource is a natural resource with the ability of being replaced through biological or other natural processes and replenished with the passage of time...
and therefore much more environmentally friendly
Environmentally friendly
Environmentally friendly are terms used to refer to goods and services, laws, guidelines and policies claimed to inflict minimal or no harm on the environment....
than modern paper farming or deforestation .
Weeds
The species Melaleuca quinquenerviaMelaleuca quinquenervia
Melaleuca quinquenervia, commonly known as Niaouli or Broad-leaved paperbark or the Paper Bark Tea Tree, is a small- to medium-sized tree of the allspice family, Myrtaceae. The plant is native to New Caledonia, Papua New Guinea and coastal Eastern Australia, from Botany Bay in New South Wales...
was introduced to Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
in the early 20th century to assist in drying out swampy land and as garden plants.
Once widely planted in Florida, it formed dense thickets and displaced native vegetation on 391000 acres (1,582.3 km²) of wet pine flatwoods, sawgrass marshes, and cypress swamps in the southern part of the state. It is prohibited by DEP and listed as a noxious weed by FDACS.
Melaleuca quinquenervia became an invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
that raised serious environmental issues in Florida’s Everglades
Everglades
The Everglades are subtropical wetlands in the southern portion of the U.S. state of Florida, comprising the southern half of a large watershed. The system begins near Orlando with the Kissimmee River, which discharges into the vast but shallow Lake Okeechobee...
and damaged the surrounding economy. Agricultural Research Service (ARS) scientists from the Australian Biological Control Laboratory assisted in solving the problem by releasing biological controls in the form of insects that feed on this species. http://www.ars.usda.gov/is/AR/archive/jan10/collections0110.htm These insects are natural predators of this species in Australia and help control the spread of the weed in the U.S.
See also
- List of Melaleuca species
- Poliopaschia lithochlora, a proposed agent for eradication
External links
- TAME Melaleuca Project - Institute of Food and Agricultural SciencesInstitute of Food and Agricultural SciencesThe University of Florida’s Institute of Food and Agricultural Sciences is a federal-state-county partnership dedicated to developing knowledge in agriculture, human and natural resources, and the life sciences, and enhancing and sustaining the quality of human life by making that information...
- Melaleuca - Australian Native Plants Society (Australia)