By Jeanne Rose
Eucalyptus Part 1 Synopsis ~ Eucalyptus leaves have been used for thousands of years, there are many species, that support the health of your body; the blog contains species information and general descriptions, and sensory characteristics.
The Eucalyptus oils from left to right are E. radiata from Australia; E. radiata from So. Africa; E. globulus from Australia; E. globulus from Portugal; E. citriodora from Malawi or Madagascar; and E. polybractea from Australia.
EUCALYPTUS LATIN BINOMIAL/COMMON NAME ~ There are over 700 Eucalyptus species, also subspecies, many varieties and even different forma (same species but different forms or chemistry) — and the ones we will include in this blog follows; the ones highlighted in bold are the oils shown above.
E. citriodora – Lemon Eucalyptus from Malawi, Madagascar, and Australia.E. dives – Broad-leafed Peppermint Eucalyptus. This contains piperitone, but there are E. dives with identical morphology but different forma which do not contain this peppermint-scented chemical.
E. globulus – Blue Gum Eucalyptus at home in southeastern Australia and there are several subspecies with a different distribution. Also found in Portugal and the USA in different terroir and thus slightly different odors. It is also named Fever tree as it was planted to drain malarial swamps in the Eastern Mediterranean area.
E. nicholii – Willow leafed Peppermint or Narrow-leaved black Peppermint Eucalyptus is endemic to New South Wales and is planted as an ornamental tree. Conservation status is vulnerable.
E. polybractea – Mallee or Blue-leaved Mallee Eucalyptus from Australia.
E. radiata – Narrow-leaf or Narrow-leaf Peppermint Eucalyptus from Australia and So. Africa.
E. smithii – Gully Gum or Blackbutt Peppermint Eucalyptus
E. stageriana – Lemon-Scented Iron Bark Eucalyptus from the Cape York peninsula
FAMILY ~ Eucalyptus is a genus or member of the botanical family, Myrtaceae. In the Myrtaceae family are some well-known plants such as Bay, Myrtle, Clove, Niaouli, and Cajuput and Tea tree. This family produces no poisonous plants.
OTHER COMMON NAMES/NAMING INFORMATION ~ In the naming of plants, we use botanical nomenclature or Latin binomial. It is a two-part name. Botanical names are Latinized. They contain a genus name plus a specific epithet (the 2nd name of the Latin binomial). The first part of the Latin binomial (Eucalyptus in this case), is the Genus name of the plant. Its first letter is always capitalized, and it is written in italics. The first name, the genus name (could be likened to our last name), is Latin for race or kind and is a group of closely related species that can interbreed.
The 2nd name (could be likened to our first name) is the species from the Latin word species or form, it too is written in italics but is not capitalized and written in lower case. Usually the smallest unit in the classification of organisms; a group of individuals of the same ancestry, of nearly identical structure and behavior, and of relative stability in nature. The individuals of a species ordinarily interbreed freely and maintain themselves and their characteristics in nature. Examples are Eucalyptus globulus, E. radiata and more.
The word Eucalyptus refers to the calyx meaning well-covered as it forms a lid over the flowers in bud (the sepals and petals of the flower are fused to form a “cap” or operculum). Each species name means something different, such as dives means rich and plentiful and refers to that species has plenty of oil or flowers, radiata means spoke-like or radiating, globulus means globe-like and refers to the globe-shaped flower pod.
HISTORICAL USES ~ Eucalyptus is a favorite home remedy in Australia, whose European settlers learned of its use from the Aborigines. Of the hundreds of species of eucalyptus trees in the world, Eucalyptus globulus is now the best known, and the one that is most used in aromatherapy.
Taxonomy and Classification History of Eucalyptus ~ There is no “botanical collection of Eucalyptus” known to have been made until 1770 when Joseph Banks and Daniel Solander arrived at Botany Bay (New South Wales) with James Cook. There they collected specimens of Eucalypts and by 1777 specimens were on their way to the British Museum and eventually named by the French botanist Charles-Louis L’Héritier.”2
The Eucalypts are native to Australia and Tasmania and grow well in many different places. They can now be found all over the world in many different types of environments. The blue gum tree (E. globulus) has been considered a cure-all by the Aborigines and to this day is a favorite home remedy.
“Everyone knows the special property of Eucalyptus leaves! The leaves of some species were crushed and soaked in water for medicinal purposes. Manna is sap which exudes from many Eucalypt trees, often from where insects have made holes. It dries into sugary white drops which fall to the ground. Delicious! Bowls and dishes were made from the heavy bark. Those gnarled round growths on the trunk were used as well. The Kulin people in southern Victoria, made bowls called ‘tarnuks’ to carry water. Some had rope handles. People along the Murray River made canoes from the bark of eucalypts (e.g. River Red Gum, E. camaldulensis). They cut the bark to shape about 3 meters long then held it over a fire, so that the sides would curl. Both ends were tied with inner-bark fiber rope and wooden stretchers were used to prevent the sides collapsing.”3
EUCALYPTUS ~ WELL-KNOWN AND MOST-USED SPECIES
E. australiana (see E. radiata) “is used for throat problems and Jeanne Rose says it is a great lung cleanser”1.
E. citriodora, called Lemon Eucalyptus and containing the aldehyde citronellal has specific therapeutic properties. Because of the content of citronellal and up to 20% citronellol, this essential oil is a powerful bug repellent and can replace Citronella oil wherever a repellent is needed. Firstly, it smells better than Citronella oil, contains more citronellal and works just as well or better to repel insects. A golden-yellow with sometimes a touch of pink color, clear like water, non-viscous, medium intense odor (6-7 on a scale of 1-10),the scent is strongly citrus with a sweet fruity subsidiary note and floral back note. Strong citrus taste.
The chemistry is 28-32% limonene, 21% citral (geranial + neral), 7-9% terpinolene, 4-6% para-cymene, 1,8-cineole, methyl geranate, 2-3% pinene, alpha-phellandrene, linaloöl, geranyl acetate, 1-2% terpinene-4-ol, nerol, terpineol, neryl-acetate. The essential oil is utilized as a source of citronellal (> 70 %).
The essential oil properties are anti-viral, anti-bacterial, antiseptic, and decongesting. [According to Oriental principles — specific conditions indicate the choice of E. citriodora over all other species of Eucalyptus. Particularly discussed are when the deficiency pattern is hot phlegm with symptoms of heat. These symptoms include red face, dry mouth, restlessness, yellow sticky mucus in the lungs and sinus. The tongue is thick with a yellow coat.] E. citriodora also has a more powerful sweeter odor than Citronella oil and is thus more pleasant in its acceptance and is economically in the same category. Also, analgesic (relieving pain) by external application, calming and sedative by inhalation and possibly anti-hypotensive (reducing high blood pressure) by inhalation or when used in massage. An excess of this oil can be upsetting and disturbing both physically and psychologically. Some Aromatherapists consider that this particular Eucalypt is best reserved for summer use as it is more refreshing. It can be very sedating and is particularly well-suited for the bath.
E. dives Schauer CT piperitone, [Broad-Leafed Peppermint] Tree. The word Eucalyptus means well-covered, (that the flower bud has a cap) and dives is the word for rich and plentiful and refers to the flowers or the leaf oils. This is a medium tree to 25 m, widespread over SE NSW and parts of Victoria, it lives in poor soil, with open to dense canopy, trunk solitary and erect, bark fibrous, juvenile leaves opposite and mature leaves alternate, with white to cream-colored profuse flowers. The essential oil is a pale gold to colorless oil, clear through, non-viscous and watery, medium intensity odor (6 on a scale of 1-10) and the scent is woodland green and vegetal, very herbaceous, spicy and fruity back notes. Taste is usually minty.
The chemical profile is 34.8 to 50 % piperitone, 20-23% alpha-phellandrene, 3-7% para-cymene and various other chemicals including thujene, myrcene, terpinene, terpinolene, and terpinene-4-ol. An examination of a stand of E. dives showed that of the five trees growing within a few feet of each other, three contained an essential oil high in cineole while the other two were high in piperitone. These two different compounds smell differently and act differently. The physical characteristics were identical. The essential oil properties are disinfectant, anti-asthmatic and deodorant. This essential oil has a powerful use as an inhalant for sinus and bronchial conditions, it is diluted and used vaginally for leucorrhea or applied on vaginal warts and is useful as a room mister with other Eucalypts for short bursts of time.
Eucalyptus globulus, [Blue-gum Tree]. The word globulus means that the fruit is a little ball. This is a medium to tall tree, up to 55 m, open to a moderately dense canopy, the trunk is upright and branching, the leaves opposite becoming alternate, leaves are narrow to lanceolate and aromatic. It is widely planted throughout the world. “Tasmanian blue gum is a fast-growing, large tree making a good shadow. The peeling bark makes the white stem appear. The blue-green leaves are dimorphic. On young shoots they are oval whereas on mature branches they are characteristically sickle-shaped. The yellow-white flowers consist of filaments only. The leaves contain the well-known eucalyptus oil….”6
The characteristics of the essential oil for the virgin unrectified oil is a rich gold colored oil, clear through, non-viscous and watery, medium intense odor (7 on scale of 1-10), and the scent is strongly herbaceous, spice and green with subsidiary notes of citrus and fruity back notes; having a fresh and slightly camphoraceous odor. It has a cooling taste.
The chemical profile of the oilis63% 1,8-cineole, 22% alpha-pinene, 4.6% limonene and 2-3% aromadendrene. The essential oil properties are mucolytic, expectorant, stimulant, and a mild local analgesic. It is inhaled for deep respiratory infections or infections of the sinus and bronchial system, and apply to aching muscles and joints.
Eucalyptus nicholii – this is called [Narrow-leaf black peppermint Eucalyptus] and is endemic to New South Wales. This species was described in 1929 by Joseph Maiden and William Blakely and the specific epithet (nicholii) honors Maiden’s private secretary and “Chief Clerk, Botanic Gardens”, Richard Nicol. It is a lovely ornamental tree and grows quite well here in San Francisco and can be found in the San Francisco Botanical Garden in Golden Gate Park. “It has been shown to have herbicidal activity against certain weeds.”10
E. nicholii – San Francisco Botanical Garden, 2014, photo by Jeanne RoseE. nicholii – San Francisco Botanical Garden, 2014, photo by Jeanne Rose
Eucalyptus polybractea – [Blue Mallee] Polybractea means many bracts referring to the reproductive structures. “The Blue Mallee have the potential to become a new industrial crop for much of the cereal growing areas of Australia, providing alternative income and environmental salvation for farmers with land at risk to salinization.”4 An evergreen multi-stemmed shrub, up to 8 m high common to semi-arid interior of New South Wales and Bendigo in Victoria. It flowers from March to June and then sometimes again in September, the blossoms occur in clusters in leaf forks. The essential oil is a colorless, non-viscous, intensely smelling odor (7 on a scale of 1-10) with a bitter vegetable taste. The scent is herbaceous with Cumin-like overtones, a fruity subsidiary note, and a vegetative spicy back notes.
The chemistry is 54.5% cineole, 19.7% beta-phellandrene, 6.8% alpha-phellandrene, 2.7% limonene, 1.6-1.9% each of alpha-pinene, alpha-thujene, sabinene, myrcene, terpinene-4-ol, and cryptone. The essential oil properties are mucolytic, expectorant (inhale with other essential oils), antiviral, anti-malarial and USES include externally on warts (doesn’t work that well), including genital warts. In the past, this Eucalyptus oil has been taken internally for intestinal parasites and for male sexual problems.
Eucalyptus radiata — [Narrow-leaf Eucalyptus]. The buds radiate out on the stems. This is a small to tall tree, to 30 m, common to NSW and Vic., occurs in a wide range of soil types, with a dense canopy, solitary trunk, bark rough, juvenile leaves initially opposite and then alternate and very aromatic. The essential oil is a colorless oil, clear through, non-viscous/watery, intense odor (8 on a scale of 1-10), the scent is a camphoraceous, herbal, spicy and back note of fruit and a vegetal dry down with a spicy astringent taste .
The chemistry is 50-70%1, 8-cineole, 8-32% alpha-terpineol, 6-8% limonene, 2-4% alpha-pinene, 1-2% myrcene, beta-phellandrene, terpinene-4-ol, and terpinyl acetate. It is antiviral, mucolytic and expectorant and is indicated for the respiratory system from top to bottom. It works as a really great lung cleanser and honey gargle for the throat. It is useful for cases of vaginitis, acne and sinus infections. This EO is considered gentle by most practitioners and can be smelled directly from the diffuser to treat those stubborn sinus infections.The uses are that it is inhaled and specific for sinus infection and pain, wet coughs, smells great and is cooling for hot flashes, used for skin ailments such as acne, can be used (diluted) on tampons for vaginitis.
‡can be irritating for some
A GOOD FORMULA … For those stubborn sinus infections — limit inhalation to 1-3 minutes every 15 minutes. [for a truly stubborn sinus infection alternate this with Inula helenium.] A good formula is 5% E. radiata + 5% R. verbenone + 90% carrier and used externally as a rub or massage over the sinus area and chest. The carrier can be Calendula oil http://jeanne-blog.com/calendula-when-and-how-to-make-infused-oils/
Eucalyptus smithii, or gully gum, [Blackbutt Peppermint] or Smith’s Eucalyptus — This is a native tree of northern Victoria and southern New South Wales, Australia. [well-covered, (the flower bud has a cap) and after H. G. Smith, a chemist who investigated the oils of the Eucalypts]. It naturally occurs on the lower slopes, gullies, and swamps, where soil does not dry out. This is a pale-yellow oil with a pink cast, clear through, non-viscous/watery, not intense odor (3-4 on a scale of 1-10), the scent is very fruity, citrus with back notes of herbs and spice. Fruity taste.
The oil chemistry is 78% cineole, 8 % alpha-pinene, 6% limonene, 2% alpha-terpineol. It is mucolytic, anti-infective, disinfectant, local analgesic, calming and has many uses. E. smithii is a mild and gentle oil, particularly useful for children or a sensitive person’s respiratory complaints. It can often be used neat on the body as a preventative, in the diffuser as a room deodorizer, in massage oil for painful joints and muscles or inhaled for nighttime calm. About 78% cineole with some limonene. Mild and gentle and particularly useful for children’s or sensitive persons respiratory complaints and can be inhaled during the night for calmness.
Eucalyptus stageriana [Lemon-scented Iron Bark Eucalyptus]. — This plant was named after K.T. Staiger, a former Government Analytical Chemist in Queensland. The organoleptic’s of the oil – is a very pale light yellow, clear through, non-viscous and watery, not intense odor (4 on a scale of 1-10), the scent is citrus, woody, vegetal and herbaceous with a fruity back note. Spicy vegetal taste with a bite.
The oil chemistry is 28-32% limonene, 21% citral (geranial + neral), 7-9% terpinolene, 4-6% para-cymene, 1,8-cineole, methyl geranate, 2-3% pinene, alpha-phellandrene, linaloöl, geranyl acetate and 1-2% terpinene-4-ol, nerol, terpineol, and neryl acetate. The EO is anti-viral, anti-bacterial, antiseptic, decongesting and is useful in the vaporizer to scent rooms and cleanse the air. It can be used in skin care products in blends with other oils. Perfumery and toilet preparations.
EUCALYPTUS ~ COUNTRIES OF ORIGINS ~ Eucalypts originated in Australia, but many species are now grown elsewhere such as California, Portugal, Madagascar, and various countries in Africa. Eucalyptus are grown in many countries such as Uruguay that uses species in forestry. They were introduced to Brazil in 1910 for timber and charcoal industries. “Much of Madagascar’s original native forest has been replaced with Eucalyptus, threatening biodiversity by isolating remaining natural areas” (see Wikipedia).
EDEN BOTANICALS HARVEST LOCATION ~ Australia, Madagascar, Malawi, Portugal
ENDANGERED OR NOT ~ Several unique species are endangered but in general Eucalypts are not endangered at this time and are in fact being allowed to take over areas formerly growing other species that it does endanger biodiversity, overly draining areas of groundwater and they have been banned in certain areas for this reason.
EUCALYPTUS ~ GENERAL DESCRIPTION OF PLANT HABITAT AND GROWTH .. “The Eucalyptus tree is a large, fast-growing evergreen that is native to Australia and Tasmania. The tree can grow to 375-480 feet (125-160 meters). Eucalyptus belongs to the myrtle (Myrtaceae) family”5. This is an evergreen tree, widely distributed in Australia and is about 75% of the flora of this land. These trees often exhibit a different juvenile phase with differences in shape, position, and color of the leaves. There are often different chemical forms and forma of species of the tree.
“Eucalypts are heavy feeders with deep roots that suck up ground water from deep within the soil. These trees store water in their roots and therefore can be an emergency source of drinking water. Because of this characteristic, Eucalypts have been planted in mosquito infested marshes to drain the marshes. This kills off the mosquitoes, which are responsible for spreading malaria. Malaria causes cycling fevers and because the Eucalypts disrupt the mosquito habitat as well as being a good herbal leaf tea to reduce fever, the Eucalypts have a common name of Australian Fever tree.”1
EUCALYPTUS ~ PORTION OF PLANT USED IN DISTILLATION, HOW DISTILLED, EXTRACTION METHODS ~ Eucalyptus leaves are harvested and then steam or hydro-distilled. This is briefly discussed in Bush Sense, a book by Mark Webb.
Eucalyptus globulus commonly called Blue Gum. This is now the most commonly used and well known of the Eucalypts. Composed of up to 75% cineole it is excellent for all respiratory and sinus complaints. “When this oil is first distilled it contains cuminaldehyde, which has an unpleasant odor and causes coughing. Since Eucalyptus oil is used in the treatment of coughing this oil is therefore rectified, that is, re-distilled to get rid of this chemical and thus the potential for provoking the cough reflex.”7 [I am unable to find the origin of this statement.] “To extract essential oils from many Eucalyptus species, vacuum distillation is done at lower temperatures, avoiding the change in essential oil chemical composition during the distillation.10”
The leaves and twigs are steam-distilled. The tree can be harvested in 7 years by cutting off the tops and then they continue to grow back from the stumps as much as three times before they need to be replaced. “To extract essential oils from many Eucalyptus species, vacuum distillation is done at lower temperatures, avoiding the change in essential oil composition during the distillation.10”
EUCALYPTUS ~ YIELD: Yields vary according to the species, One type of Eucalyptus produced upon distillation approximately 2.5 lbs. (1 kg) of Eucalyptus oil from 125 lbs. (50 kg) of Eucalyptus leaves.
A chart of organoleptic characteristics of six types of Eucalyptus essential oilOrganoleptic Characteristics of six types of Eucalyptus essential oil
EUCALYPTUS ~ ODOR DESCRIPTION/ AROMA ASSESSMENT ~ We all know the eponymous scent of Eucalyptus and yet within the genus, there is still difference among the species and within each species depending upon terroir there is a difference as well.
For example, Eucalyptus radiata is available from several different terroirs (areas) including Australia, Tunisia, and South Africa. The odor from South Africa and Australia, two locations, two terroir, two different scents for the same species. E. radiata from Australia has a rich evocative strong and pungent herbaceous scent and because of the a-pinene, a scent that is also coniferous and green. The odor from the E. radiata of South Africa is also pungent and herbaceous but with a vegetative back note.
Regarding E. globulus, the scent of the oil that is harvested from Australia and the one from Portugal is really very different. The GCMS of the oil from Portugal “showed 1,8‐cineole, α‐pinene, limonene, aromadendrene, δ‐cadinene, and globulol were the most abundant compounds, representing 93% of the total oil.”8 E. globulus from Australia was usually 60-70% cineole and the scent reflected this strong cineole (camphoraceous) scent. The results of the study of Moroccan E. globulus “revealed that essential oil yield and the total oil of Eucalyptus globulus were 1.21% and 63.96% respectively. 54 compounds were identified in the essential oil and the main constituents of the essential oil were: 1.8-Cineole (22.35%), Limonene, (7.01%), Solanol (6.05%), P-pinene (5.20%), Transverbenol (4.02%), Terpinene-4-ol (3.10%), Aristolene (2.35%), terpinyl acetate (2.10%), Isosativene (1.85%), sabinene (1.49%), [alpha]-myrcene (1.15%) and a-terpineol (1.10%).”9 Because of the lower amount of cineol here versus the oil from Australia, I would surmise a great difference in the intensity and description of the scent.
E. citriodora scent from my previous samples is strongly citrus with a sweet fruity subsidiary note and floral back note and the sample from Madagascar is also citrus with a softer fruity note and an also a light floral and balsamic back note.
Key Use ~ The Oil of Respiration
I have made great use of the website called www.google.scholar.com for a variety of interesting scientific studies.
See also http://www.aromaticplantproject.com/articles_archive/Australian_Essential_Oils.html
Our thanks to Jeanne on her amazing blog, please make sure to check it out!