Artemisia arborescens essential oil of the Pacific Northwest

by Dr. Robert Pappas & Sylla Sheppard-Hanger

Introduction to the Artemisia family:

Artemisia is a fairly large genus within the family of the Asteraceae (Compositae), with 200 individual species known, which are usually found in dry areas. They are invariably found as small fragrant shrubs or herbs and most yield essential oils. Some of these oils have found uses in perfumery and medicine (as, for example, vermifuges, stimulants, etc.) whereas the leaves of some species are used as culinary herbs. The plants themselves as are popular among gardeners as cultivated ornamentals.

Several of the species that produce essential oils are found in the chart below:

Plant Common name Habitat Herb or Essential oil use [i] Safety info
A. afra afra von Jacquin Lanyana, layana, African absinthe, wildeals, South African wormwood   Herb: Anticatarrh, antimigraine, mucolytic, vermicide [1] 
vapor from boiling leaves inhaled for respiratory ailments[ii] 
EO: exhibits anti-fungal activity[iii] 
No formal safety testing of EO; appears possible irritant, moderately toxic; potentially very toxic 
A. abroatanum L. southernwood, lads love, old man  S. Eur Herb: digestive, antihelmintic, emmenagogue 
No formal safety data: presumed toxic
A. absinthium L. absinthe, absinthium, wormwood, green ginger, armoise  Eur. medicinal and absinthe 
(harmful liqueur; source of Afsanteen, a drug used in chronic fever, swellings and inflammation of the liver- one of[2]; useful as tonic and stimulant 
EO: antihelmintic, insect repellant, digestive stimulant, mild tonic, febrifuge 
One of best sources of azulene [iv] 
EO: Tested at low doses non toxic; non irritant and non sensitizing; banned for use based on absinthe poisoning
A. annua L. Annual wormwood, sweet Annie  Europe, naturalized in N. America Herb: efficacious antimalarial in China (huanghuahaosu); 
EO: antihelmintic, antispasmodic, carminative, mucolytic
No formal safety testing of EO; presumed moderately toxic
A. arborescens artemesia, great mugwort, arborescent mugwort  Morocco, Pacific NW USA EO: anti-inflammatory, antihistamine, anticatarrh, choleretic, mucolytic  No formal safety testing; appears safe at low doses
A. cina Berg ex Polj Levant wormseed, Turkestan    Herb: medicinal, antihelmintic (santonin) known as santonica  N/A
A. drancunculus L  tarragon Euras leaves as aperient, stomachic, stimulant, febrifuge, spice for flavoring (vinegar, with fish); 
EO: antihelmintic, antibacterial, anti-inflammatory antispasmodic, carminative 
Tested at low dose, not toxic, non irritant, non sensitizing 
Mutagenic data
A. glacialis L and A. Laxa (Lam.) Fritsch   Alps Herb: flavoring for genepi liqueur  N/A
A. herba alba Asso White mugwort 
Two types davanone type (up to 55% davanone) (P&F) and thujone type (up to 71 % a-thujone, camphor 

Herb: wormwood of the Bible; 
EO: anti-infectious, antibacterial,[v] emmenagogue, lipolytic, mucolytic, cholagogue, parasiticide, viricide 

(the genuine Ã¢â‚¬Å“Armoise oil” of perfumery) 

EO: Non-irritant, non-sensitizing, and non-phototoxic.

Assumed very toxic. 

A. maritima L.   Euras

Herb: Source of santonin (vermifuge and antifertility drug) 3 used as decongestant, stomachic, laxative and tonic 

EO: thujone[vi], cineole, several monoterpenoids [vii] 

No formal testing of EO: assumed very toxic 
A. pallens Wall Davana  

Herb: often grows in neighborhood of sandalwood trees; important component in garlands and bouquets in India;

EO: used in flavor (cakes, pastries, tobacco and costly beverages); Anticatarrh, bactericidal, cicatrizant, mucolytic, nervine (anti anxiety, low dose)

Main constituent: davanone 

EO: Non-irritant, non-sensitizing and non-phototoxic. Low toxicity 
A. pontica L. Roman wormwood SE Europe Herb: flavor of vermouth  
A. silversiana Ehrh ex Willd.    

Herb: tonic, deobstruent, febrifuge, anthelmintic, and antiseptic; used as fodder

EO: reported as a good source of Chamazulene[viii] 

A. tridentata Nutt “sage brush” of the south west USA. Unfortunately being wind pollinated are often the source of hayfever problems  N. America Herb: used medicinally also as tea N/A
A. tilesii Ledeb   Arctic Herb: Medicinal 
(Eskimos), properties like codeine[ix
A. vulgaris L. Common mugwort, armoise, Indian wormwood  Euras

Herb: Leaves condiment, also used in moxibustion, and magic and superstition

EO: Antihelmintic, antispasmodic, stimulant, tonic, vermifuge 

EO: oral toxin, low dose on skin: non irritant, non-sensitizing 


Artemesia arborescens is a morphologically highly variable species (or mixture of species) with gray-green to silver leaves. It is native to the various habitats of the Mediterranean region, where it occurs as a shrub to one meter in height. According to popular folklore, the plant was spread by Moorish invaders and Knights Templar during the times leading up to the Crusades.

Colonies of A. arborescens from the European shores and the Mediterranean islands may have originated in North Africa or the Middle East. Most members of the species are highly scented. Some versions or cultivars are grown and highly prized in British gardens and these may be difficult to classify botanically as many have similar characteristics.

artemesia arborescens

Artemisia varieties

The NCCPG Artemisia Collection [x] currently holds the following variants of “arborescens”:

Named cultivars: Brass Band, Faith Raven, Porquerolles, Powis Castle; and other versions: “Crete”, Hort, Barcelona, Madrid, Oldenburg.

Vapor profiling was carried out on Brass Band, Faith Raven and Powis Castle, and all were found to be markedly similar in composition. Thujone was prominent, however the chromatogram was different from A. absinthium (wormwood). Twibell considers that vapor profiling gives a permanent scientific record of the odor of scented plants and can be used to aid taxonomic determination or discrimination.[xi]

Additional methods of classification

Barberlo, et al. (1991), combined methods of headspace sampling, thermal desorption, and capillary GC and successfully resolved the variant of Artemisia and use of mass spectral data provided help in identifying interesting components. This article clearly shows that the cultivar Powis castle appears to share a common ancestry with two other similar cultivars (Brass Band and Faith Raven), originally from Greece. However it is unlikely that it is a hybrid between A. absinthium and A. arborescens.[xii]

However, Tucker et al., 1993, said that when elucidation of the inheritance of essential components in the genus Artemisia, the essential oil of Powis Castle does not contradict a putative origin from A. Absinthium x A. arborescens. [xiii]

Few analysis have been reported for A. arborescens, but two have been characterized: the high chamazulene type and the high beta-thujone type (Codignola, 1984.) [xiv]

Odor description:

Moroccan high thujone type: Deep blue to blue black oil with odor characteristic of plant and distinctly thujone-like; powerful, minty and woody, with a definite slight milk-like note presence. Dry-out is creamy fruity-with the impression of a fruity (almost apricot/raspberry) note with some lactonic character.

Pacific NW high chamazulene type: In contrast to the thujone type, this deep blue-black colored high chamazulene type of oil does not present a thujone character, but is more low-key in impact being fresh, slightly sweet, slightly minty at first, becoming much more minty after five minutes, with a lift reminiscent of angelica seed oil. There is also a hint of fruitiness. The dry-out is minty, fruity-apricot, sweet with some fresh tobacco leaf character. In comparison to the normal type, the dry-down of the Pacific NW type is more fruity, and makes the normal type look woodier and soapier in comparison.[xv]

History: The particular oil discussed in this paper was from George Sturtz, a producer who has spent years experimenting with producing the oil in Oregon. The probable introduction of the plant was via a herb grower and collector from southern Oregon about 10 years ago. At the time, Sturtz was collecting new accessions to see what the potential was for production. Most of his life’s work has dealt with finding uses for the native plants of the Northwest. He has also collected many aromatic plants from other parts of the world. He became interested in the Artemisia genus after reading a PhD dissertation about 20 years ago. Amazed at how little was known of this genus in America, and particularly in the NW, he began to study, grow and distill the plants he collected to determine their usefulness from oil production and culture. A. arborescens, like some other Artemisias have azulenes of various kinds in their oils. A. arborescens oil has the highest amount of chamazulene of any essential oil known.

Plant Habitat

The plant is hardy in the north-west USA only during winters of very mild temperatures, otherwise it must be propagated and transplanted as an annual every year, making it costly. The above mentioned producer maintained the original plants in the greenhouse, as the plant is not hardy in climates that get much below freezing. The wet and cold usually kill it quickly. The plant is propagated by tip cuttings. The plant was identified by university herbarium specimens and flora of Europe.

The yield of oil is quite low, only about 0.3%. The oil is also hard to isolate, since some fractions are heavier than water requiring special techniques to recover the oil. One can also try to influence the density of the water.

Growing Trials

A trial was carried out in Spring 1999 harvesting and distilling the aerial parts of approximately 700 cultivated plants, which gave a total oil yield of 280 g. The season was cooler than normal, and yields of other essential oil crops was also depressed by about 15-20%. He calculated to figure the yield per acre around 10 to 12 lbs. The price would have to be around $1000/lb. to be economically feasible at current conditions. Plants are harvested at the end of the growing season, about mid October.


Azulene content

The azulene content may vary from season to season, last year reaching record highs of about 40%. Chemical information on previous distillations of the Northwest type oil can be found in the 1993 JEOR article. A side by side comparison of the chemical breakdown of the high thujone type with the high chamazulene type is given below.

Comparison of Moroccan and American A. arborescens Oil

Artemisia arborescens Morocco High thujone type USA High Chamazulene type
Component Area % Area %
alpha-thujene 0.31 0.35
alpha-pinene 3.00 3.24
camphene 2.71 2.81
sabinene 3.99 0.23
myrcene 9.10 5.05
alpha-Terpinene 1.65 1.11
para-Cymene 2.10 1.04
Limonene 1.17 1.06
gamma-Terpinene 4.12 1.86
E-Sabinene hydrate 1.07 2.87
Linalool 2.06 0.65
alpha-thujone 1.00 nd
beta-Thujone 30.06 nd
camphor 21.67 16.71
Terpinen-4-ol 3.34 2.05
alpha-Terpineol 0.37 0.19
copaene 0.27 0.44
beta-bourbonene 0.24 0.21
beta-Caryophyllene 0.37 3.56
Germacrene D 2.03 7.15
Chamazulene 1.45 39.60
unident.diterpene nd 8.91


Interestingly, not only does the Northwest type exhibit more than 20 times the chamazulene level of the typical Moroccan type but it also has no detectable amounts of thujone, which is obviously desirable from a toxicity standpoint. In addition, the Northwest variety also contained a relatively high amount of an unidentified diterpene. Diterpenes, when they are present, are rarely found at greater than 1% in essential oils. Whether or not this diterpene would have any potential therapeutic effects is a topic that needs further investigation.

With a chamazulene content, typically ranging from 30 - 40%, the Northwest variety of A. arborescens is at the top of the list of known chamazulene containing oils. The table below is a comparison the title oil with the other primary chamazulene oils.

Comparison of the Main Chamazulene Containing Oils

Botanical Oil Typical chamazulene %
American Arborescens (Artemisia arborescens) 30-40%
Yarrow or Milfoil (Achillea millefolium) 2-27%
German chamomile (Matricaria chamomilla) 2-12%
Blue tansy (Tanecetum annuum) 1-3%
Moroccan Arborescens (Artemisia arborescens) 1-2%
Wormwood or Mugwort (Artemisia absinthum) 0-4%

Effects and Efficacy

Essential oils that contain chamazulene are important in therapeutic applications because of its apparent radical scavenging activity. Interesting research supporting this activity was carried out by Rekka E.A. (1996), who investigated the role of chamazulene in vitro experiments using an iron(II)/ascorbate system to generate hydroxyl radicals inducing membrane lipid peroxidation in liver microsomes. It was seen that chamazulene was a potent hydroxyl radical scavenger and effectively inhibited lipid peroxidation.[xvi] The ability of chamazulene in radical scavenging is what is thought to responsible for its effectiveness in treating inflamed skin conditions.

Artemisia arborescens was shown to have weak antibacterial action except towards Clostridium sporogenes when tested with twenty-five test bacteria. [xvii]

Skin care applications may include: burns, sensitive skin, acne, keratosis, sunburn, inflammations & infections of the skin (Ikan, et al. (1993); Untested oil, avoid use on sensitive or damaged skin
For respiratory problems, inhalation could be beneficial for bronchitis, (asthmatic & catarrhal), coughs, sinus and chest congestion.

Practical uses: this author (SSH) has successfully used this oil in:

  • inflamed skin conditions including pre- and post-radiation treatments (as compress and water spray); sunburn (water spray)
  • topical treatment for inflamed and sensitive skin (5%) and for surgical scars (mixed 1:1 with Helichrysum italicum, 5% formulation in fractionated coconut oil;
  • inhalation for respiratory infections, and inflamed sinus (see below)
  • topical sinus treatment (5%) (mixed with tea tree, and peppermint 2:10:2).

Typical aromatherapy uses of A. arborescens include: anti-inflammative, antiallergenic (?(Penoel), antihistamine, anticatarrh, choleretic, mucolytic, (Sheppard Hanger, 1995)

Conclusion: Because this oil has had no formal safety testing, it is best avoided in pregnancy, and for babies & children. But it appears safer than other Artemesia arborescens oils because the thujone content is negligible. They would tend to be in the moderately toxic category. Thujone, which can be quite toxic, occurs in two isomeric forms, the a-form being considerably more toxic than the b-form. This particular oil has a negligible amount of either.

[i] Sheppard-Hanger, S. The Aromatherapy Practitioner Reference Manual, 1995.
[ii] Watt M.J., Beyer-Brandwijk ,The medicinal & poisonous plants of Southern & Eastern Africa, p199-202 pub. Livingstone London (1976)
[iii] Gundidza M “Anti-fungal activity of essential oil from Artemisia afra Jacq.― Cetr. Afr. J. Med 1993 39(7) 140-2.
[iv] Kucera, M. Pharmazie 11 (9): 604-09 (1956).
[v] Yashphe J et al “Anti-bacterial activity of Artemisia herba-alba― J. Pharm Sci 1979 68(7) 924-5
[vi] Thakur R.S. & Misra L.N. (1989) “Essential oils of India Artemisia” 11th Intl. Congress of Essential Oils, Fragrances & Flavours 12-16 Nov 1989 New Delhi, India Proceedings pub Aspect Publishing, London 1990 Vol 4 p127-135.
[vii] Singh, A., V.K.Kaul, V.P.Malrajan, A.Singh, I.N. Imsra, R.S. Thakur and A. Husain Indian J. Pharm Sci. (5 137-38 (1986)
[viii] Thapa, R.K., et al, Indian J. Pharm 30:283 (1968)
[ix] Mabberly, D.J. The Plant-Book, A portable dictionary of the higher plants, Cambridge University Press, 1993.
[x] Dr. John D. Twibell, Elsworth Herbs, 31 Smith Street, Elsworth, Cambridge, CB3 8HY
[xi] Twibell,J. D. “Plant Identification from Vapour analysis - A short study of Artemisia arborescens varieties”, fax from author, 1999.
[xii] Barberlo, J., Twibell, J. “Chemotaxonomy of Plant Species using Headspace Sampling, Thermal Desorption and Capillary GC, Journal of High Resolution Chromatography, 1991.Dr. Alfred Huethig Publ.
[xiii] Tucker, A.O., Maciarello, M.J., Sturtz, G. “The Essential Oils of Artemisia “Powis Castle” and its Putative Parents, A. absinthium and A. arborescens, J. Essent.Oil Res., 5, 239-242 (May/Jun 1993)
[xiv] A. Codignola, L’huile essential de Artemisia arborescens L spontanee en Italie et cultivge au Maroc, Allionia, 26, 89-95 (1984).
[xv] Tony Burfield private communication: snipped extract with permission from forthcoming book: The Odour Profiling of Essential Oils to be published in 2000, by Atlantic Institute of Aromatherapy.
[xvi] Rekka E.A., Kourounakis A.P., Kourounakis P.N. (1996) Res.Com. Mol. Parmacol. 92(3): 361-364
[xvii] Ikan R, Deans SG, Vavid U, (1993) “Antibacterial, antifungal and antioxidant properties of five essential oils from Israel.”, Programme Abstracts, 24th Int Symp Esent Oils.

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