[BoDD logo]


Google uses cookies
to display context-
sensitive ads on this
page. Learn how to
manage Google cookies
by visiting the

Google Technologies Centre

 ▼ ▼ ▼ ▼ ▼ ▼ ▼


 ▲ ▲ ▲ ▲ ▲ ▲ ▲

[BBEdit logo]




(Myrtle family)


3000 species in 100 genera are found in warm regions, chiefly in Australia and tropical America. Many have edible fruits.

Backhousia citriodora yields an essential oil.

[Summary yet to be added]

Backhousia australis G.Benn.
Australian Lancewood

Following a report by Maiden (1919) that splinters of Acacia shirleyi Maiden (fam. Leguminosae), which is also known as Australian lancewood, could cause painful wounds, this and other lancewoods have been included in lists of dermatologically hazardous woods (Schwartz et al. 1947, Schwartz et al. 1957, McCord 1958) without any published evidence (Woods & Calnan 1976).

Corymbia maculata K.D.Hill & L.A.S.Johnson
[syn. Eucalyptus maculata Hook.]
Spotted Gum, Spotted Iron Gum

In some parts of Queensland, timber getters and sawyers developed "spotted-gum rash" from Eucalyptus maculata timber. In other areas of the country the disorder did not seem to occur (Maiden 1909b, Cleland 1925).

Eucalyptus L'Hér.

500 species are found in Australia and two or three species in Indo Malaysia. The barks of the trees of this family vary considerably but, being easily recognised, are an aid in classification and account for some of the common names. The most common kind is smooth bark (gum trees) which exfoliates in patches. Other kinds have scaly bark (blood woods, etc.), thick and fibrous bark (stringy barks), hard furrowed bark, often black with age (iron barks). Eucalyptus oils vary in chemical composition.

Eucalyptus camaldulensis Dehnh.
[syns Eucalyptus acuminata Hook., Eucalyptus longirostris F.Muell. ex Miq., Eucalyptus rostrata Cav., Eucalyptus rostrata Schltdl.]
Blue Gum, Murray Red Gum, River Red Gum, Yarrow
An itch common in red gum forests is caused by the decayed cocoon of a moth. When this dust comes into contact with a man's body it causes a most tormenting itch which is almost unbearable, but it only appears to take effect when the body is heated and perspiring (Maiden 1921a, Cleland 1925, Watt & Breyer-Brandwijk 1962).

Eucalyptus globulus Labill.
[syns Eucalyptus globulosus St.-Lag., Eucalyptus gigantea Dehnh.]
Blue Gum, Eurabbie, Gippsland Blue Gum, Southern Blue Gum, Victorian Blue Gum, Maiden's Gum


Eucalyptus gunnii Hook.f.
[syns Eucalyptus divaricata McAulay & Brett, Eucalyptus whittingehamei Landsb., Eucalyptus whittingehamensis G.Nicholson ex Elwes & A.Henry]
Cider Gum


Eucalyptus leucoxylon F.Muell.
Blue Gum, Inland Blue Gum, Large-Fruited Blue Gum, Red-Flowered Yellow Gum, South Australian Blue Gum, Water Gum, White Ironbark, Yellow Gum


Eucalyptus macrorhyncha F.Muell. ex Benth.
[syn. Eucalyptus scyphoidea Naudin ex Maiden]
Cannons Stringybark, Capertree Springybark, Red Stringybark


Eucalyptus microcorys F.Muell.


Eucalyptus pilularis Sm.
[syns Eucalyptus incrassata Sieber ex DC., Eucalyptus ornata Benth., Eucalyptus persicifolia Lodd., G.Lodd. & W.Lodd., Eucalyptus semicorticata F.Muell.]

The bark or wood of these species have been reported to produce dermatitis (Maiden 1909b, Cleland 1914 - referring to a case described by Maiden of dermatitis attributed to Eucalyptus hemiphloia, Cleland 1925, Hanslian and Kadlec 1966). Sensitive persons are said to develop urticaria from handling the foliage (Watt & Breyer-Brandwijk 1962). Behl et al. (1966) observed that the irritant and sensitising properties are slight but that eucalyptus oil is rubefacient and that ingestion of the oil can produce skin eruptions in some individuals. Irritant effects of the oils have been reported (Galewsky 1904, 1905, Macpherson 1923). The composition of the oils (Watt & Breyer-Brandwijk 1962) suggests possible allergenicity but evidence for such an effect is scanty (Löwenfeld 1932, Greenberg and Lester 1954).

The oil is poisonous when ingested (MacPherson 1925, Cleland 1925).

Eucalyptus diversicolor F.Muell.

According to Cleland (1925), irritation attributed to handling the timber from the jarrah (Eucalyptus marginata D.Don ex Sm.) was later found really to have been caused by the wood from the karri (Eucalyptus diversicolor) that had been "powellized" and hence contained arsenic, the possible actual cause of the irritation.

Eucalyptus irritans L.A.S.Johnson & K.D.Hill

This tree is to be found in northern Queensland. The epithet is from the Latin irritans, irritant, in reference to the finely prickly bark (Hill 1999).

Eucalyptus moluccana Roxb.
[syn. Eucalyptus hemiphloia F.Muell. ex Benth.]
Coastal Grey Box, Grey Box, White Box, Gum-Topped Box

A plant collector who climbed Eucalyptus hemiphloia developed a red rash where particles of the fine bark had come into contact with his skin (Maiden 1909b, Cleland 1925).

Eucalyptus leucoxylon F.Muell.
Blue Gum, Inland Blue Gum, Large-Fruited Blue Gum, Red-Flowered Yellow Gum, South Australian Blue Gum, Water Gum, White Ironbark, Yellow Gum

The sawdust causes spasmodic rhinorrhea (Cleland 1925).

Eucalyptus moluccana Roxb.
[syn. Eucalyptus hemiphloia F.Muell. ex Benth.]
Coastal Grey Box, Grey Box, White Box, Gum-Topped Box

A plant collector who climbed Eucalyptus hemiphloia developed a red rash where particles of the fine bark had come into contact with his skin (Maiden 1909b, Cleland 1925).

Eucalyptus saligna Sm.
Sydney Blue Gum

Three carpenters developed erythema multiforme after working with the wood stated to be of this genus probably of this species, with Dalbergia nigra, and with Macherium scleroxylon respectively (Holst et al. 1976).

Melaleuca alternifolia Cheel
[syn. Melaleuca linariifolia var. alternifolia Maiden & Betche]
Paper Bark, Narrow-Leaved Tea Tree, Tea Tree

Tea tree oil, also known as melaleuca oil, is an essential oil distilled from the leaves of this and some other closely-related native Australian species.

[Further information available but not yet included in database]

Melaleuca leucadendra L.
[syns Cajuputi leucadendron Rusby ex A.Lyons, Leptospermum leucodendron J.R.Forst. & G.Forst., Meladendron leucocladum St.-Lag., Myrtus leucadendra L.]
Cajeput, Paperbark Tree, River Tea Tree, Swamp Tea Tree, White Tea Tree, White Wood

The common name paperbark tree refers to the shedding of the bark which remains partially attached to the tree. The bark is used as a rubefacient in India (Behl et al. 1966).

A highly sensitive individual in the immediate vicinity of a number of trees in bloom may experience a fine, burning rash, especially on the face, and sometimes headache and nausea. A small boy was covered with rash from head to foot after handling a branch and licking a cluster of seedpods. When a tree was being dug up, the roots touched a woman's wrist and produced a rash and blisters. The irritant factor is apparently the cajeput oil which is commercially distilled from the fresh leaves and twigs and used as a counter irritant and rubefacient, and applied to skin complaints as a parasiticide (Morton 1962a, Morton 1971).

Oil of Cajeput, a volatile oil obtained from this species, contains a phenolic compound which chelates copper from the distillation vessels and changes from a yellow to a green colour (Lowry 1973). Artificial colouring may be added to produce a desired green colour (Nasution et al. 1973). Eucalyptol (cineol) is a major constituent of the oil (Budavari 1996).

The oil has rubefacient properties and is included in a variety of proprietary ointments and lotions used for rubbing into painful muscles, joints, sprains and bruises. Stuart (1979) also asserts that it is used to treat scabies. However, it can produce dermatitis and folliculitis when used for massage (Simons 1953, Greenberg and Lester 1954). A patient who had contact dermatitis from application of the oil was sensitive to eucalyptol (Sezary and Horowitz 1935).

Melaleuca linariifolia Sm.
[syn. Myrtoleucodendron linariifolium Kuntze]
Flax Leaf Paperbark, Narrow-Leaved Tea Tree, Tea Tree, Snow in Summer

Maiden (1916) described a case of a 5-year old boy who climbed this tree and when he came down complained of stinging and itching. Other cases were known to those in the locality, who called the condition "tea-tree itch". Cleland (1925) also referred to this condition, noting that it might have been caused by hairy caterpillars infesting the tree trunk.

Melaleuca nodosa Sm.
[syns Melaleuca juniperina Sieber ex Rchb., Metrosideros nodosa Sol. ex Gaertn., Myrtoleucodendron nodosum Kuntze]
Ball Honeymyrtle, Golden Honey Myrtle, Prickly-Leaved Paperbark

Handling the leaves, twigs and bark was said to produce irritation (Cleland 1925).

Melaleuca styphelioides Sm.
[syn. Myrtoleucodendron styphelioides Kuntze]
Prickly Paperbark, Prickly-Leaved Tea Tree

This species has been reported as a cause of "tea-tree itch" (Maiden 1916, Cleland 1925). See also Melaleuca linariifolia Sm. above.

Melaleuca viridiflora Sol. ex Gaertn.
[syns Cajuputi viridiflora A.Lyons, Melaleuca cunninghamii Schauer, Myrtoleucodendron viridiflorum Kuntze]
Broad-Leaved Paperbark, Broad-Leaved Tea Tree, Coarse-Leaved Paperbark, Paperbark, Swamp Paperbark

Oil of Niaouli is derived from this species (Budavari 1996); a major constituent is eucalyptol (cineol).

Myrtus communis L.
[syns Myrtus oerstedeana O.Berg, Myrtus sparsifolia O.Berg]
Common Myrtle, Greek Myrtle, Indian Buchu, Swedish Myrtle

This West Asian tree which figures in the Old Testament has long been naturalized in Europe.

The leaves of the plant yield Oil of Myrtle (Budavari 1996).

Biberstein (1927) observed a positive patch test reaction to myrtle in a 30 year old female who also reacted to Sedum spectabile Boreau (fam. Crassulaceae) and to unidentified species of Cyclamen L. (fam. Primulaceae) and Tradescantia L. (fam. Commelinaceae). None of 7 control subjects reacted. Genner and Bonnevie (1938) also refer to sensitivity to myrtle. Care should be taken when interpreting reports in which the botanical identity of myrtle has not been established because a number of other plants are known as myrtles.

Pimenta dioica Merr.
[syns Eugenia micrantha Bertol., Eugenia pimenta DC., Myrtus dioica L., Myrtus pimenta L., Myrtus piperita Sessé & Moc., Pimenta officinalis Lindl.]
Allspice, Jamaica Pepper, Pimento

The unripe fruits of this species form allspice. Allspice is irritant to the skin (White 1887); it was used like Capsicum in rubefacient plasters. Oil of Pimenta has irritant properties. It comprises principally phenols such as eugenol (Budavari 1996). 19 of 408 patients who had hand eczema (Agrup 1969) and a salad maker (Hjorth and Weisman 1972) showed positive patch test reactions to allspice.

Pimenta racemosa J.W.Moore
[syns Amomis acris O.Berg, Caryophyllus racemosus Mill., Myrcia acris DC., Myrtus acris Sw., Pimenta acris Kostel.]
Bayberry, Bay Rum Tree, West Indian Bay Tree, Wild Clove, Wild Cinnamon, Bois d'Inde, Bayrumbaum

Bay rum derived from the leaves and fruits of this species and from other ingredients used in hairdressing caused dermatitis of the face and scalp (White 1887).

Oil of Bay, derived from this species, has been reported to cause dermatitis in hypersensitive individuals (Greenberg and Lester 1954). The oil contains principally eugenol together with methyl eugenol, myrcene, chavicol, methylchavicol, citral and l-phellandrene (Budavari 1996). Contact sensitivity to eugenol and phellandrene was reported by Woeber & Krombach (1969). Photodermatitis from bay rum is not substantiated.

Psidium guajava L.
[syns Myrtus guajava Kuntze, Psidium guava Griseb., Psidium pomiferum L., Psidium pyriferum L.]
Apple Guava, Guava, Jambu Batu, Jambu Biji, Yellow Guava

The fruits are used to make guava jelly, a type of jam. The bark and roots are astringent from the tannin which they contain (Irvine 1961).

Psiloxylon mauritianum Baill.
[syn. Fropiera mauritiana Bouton ex Hook.f.]
Scratchwood, Bois à Gratter

Dust from the crumbling bark causes, itching and gives the wood its name (Stone 1921).

The genus Psiloxylon Thouars ex Tul. is monotypic; P. mauritianum is found in Mauritius and Réunion (Mabberley 1987). The genus has previously (Willis 1973) been classified in its own family, the Psiloxylaceae.

Rhodomyrtus macrocarpa Benth.
Australian Horror Tree, Cooktown Loquat, Finger Cherry, Native Loquat

Ingestion of the fruits can cause blindness (Flecker 1944, Walsh 1957).

Syncarpia glomulifera Nied.
[syns Metrosideros glomulifera Sm., Nania glomulifera Kuntze, Syncarpia laurifolia Ten., Tristania albens DC.]
Red Luster, Turpentine Tree

The wood can cause dermatitis (Mair 1968).

Syzygium aromaticum Merr. & L.M.Perry
[syns Caryophyllus aromaticus L., Eugenia aromatica Baill., Eugenia caryophyllata Thunb., Eugenia caryophyllus Bullock & S. Harrison]

The dried flower buds of this plant form the spice known as cloves (Schmid 1972). Oleum Caryophylli (oil of cloves), used in perfumery, can produce irritation (Greenberg and Lester 1954). Contact dermatitis, cheilitis and stomatitis have been reported from the oil (Sternberg 1937, Zakon et al. 1947, Silvers 1939, Gaul 1963).

Oil of Cloves contains principally eugenol together with acetyleugenol, caryophyllene and vanillin (Budavari 1996). Eugenol has sensitising properties (Greenberg & Lester 1954, Hjorth 1961, Koch et al. 1971, Woeber and Krombach 1969). Reported allergenicity of eugenol was reviewed by Opdyke (1975).

The oil produced a positive patch test reaction at concentration 1% in petrolatum, negative in 8 controls (Gaul 1963). 14 of 1147 eczema patients showed positive patch test reactions to the oil 1% in petrolatum; some were sensitive to other essential oils (Agrup 1969). One of 380 eczema patients showed a positive patch test reaction to the oil (Meneghini et al. 1971).

Oil of Cloves and eugenol can produce dermatitis in dentists (Schwartz et al. 1957). Eugenol has sensitising properties (Greenberg and Lester 1954, Hjorth 1961).

Syzygium australe B.Hyland
[syns Eugenia australis J.C.Wendl. ex Link, Eugenia myrtifolia Salisb., Eugenia myrtifolia Sims, Eugenia oleaeoides H.Perrier, Jambosa myrtifolia Heynh.]
Brush Cherry, Creek Satinash, Magenta Lilly Pilly, Scrub Cherry, Watergum

Contact sensitivity to Eugenia myrtifolia and to Medicago was reported by Anderson (1944).


  • Agrup G (1969) Hand eczema and other hand dermatoses in South Sweden. Acta Dermato-Venereologica 49(Suppl 61): 1-91
  • Anderson, C.R. (1944) Contact dermatitis from alfalfa and bur clover. Archs Derm. Syph. 5: 201.
  • Behl PN, Captain RM, Bedi BMS, Gupta S (1966) Skin-Irritant and Sensitizing Plants Found in India. New Delhi: PN Behl [WorldCat]
  • Biberstein H (1927) Überempfindlichkeit gegen Pflanzen (Sedum, Tradeskantia, Campanula, Meerzwiebel, Myrthe, Alpenveilchen, Buntnessel). [Hypersensitivity to plants (sedum, tradescantia, campanula, squill, myrtle, cyclamen, coleus)]. Zentralblatt für Haut- und Geschlechtskrankheiten 22(1/2): 19
  • Budavari S (Ed.) (1996) The Merck Index. An Encyclopedia of Chemicals, Drugs, and Biologicals. 12th edn. Whitehouse Station, NJ: Merck & Co., Inc.
  • Cleland JB (1914) Plants, including fungi, poisonous or otherwise injurious to man in Australia. Australasian Medical Gazette 35(25; 26): 541-544; 569-572 [url]
  • Cleland JB (1925) Plants, including fungi, poisonous or otherwise injurious to man in Australia. Medical Journal of Australia ii(15): 443-451 [doi] [doi-2] [url] [url-2]
  • Flecker, H. (1944) Sudden blindness after eating "finger cherries"; (Rhodomyrtus macrocarpa). Med. J. Australia 2: 183.
  • Galewsky (1904) Uber Eukalyptus-Dermatitis. Derm. Ztschr. 11: 752.
  • Galewsky (1905) Uber Eukalyplusdermatitiden. Derm. Ztschr. 12: 36.
  • Gaul, L.E. (1963) Dermatitis of the hands from oil of cloves. Skin 2: 314.
  • Genner V, Bonnevie P (1938) Eczematous eruptions produced by leaves of trees and bushes. Archives of Dermatology and Syphilology 37(4): 583-589 [doi] [url]
  • Greenberg, L.A. and Lester, D. (1954) Handbook of Cosmetic Materials. New York, Interscience.
  • Hanslian L, Kadlec K (1966b) Dřevo z hlediska hygienického (VIII). Biologicky účinné a málo účinné dřeviny. [Wood from a health perspective (VII). Trees with some or little biological activity]. Dřevo 21: 229-232
  • Hill KD (1999) A taxonomic revision of the White Mahoganies, Eucalyptus series Acmenoideae (Myrtaceae). Telopea 8(2): 219-247 [url]
  • Hjorth N (1961) Eczematous Allergy to Balsams, Allied Perfumes and Favouring Agents. With special reference to balsam of Peru. Copenhagen: Munksgaard [WorldCat] [url]
  • Hjorth N, Weismann K (1972) Occupational dermatitis in chefs and sandwich makers. Contact Dermatitis Newsletter (11): 301, 300 [url]
  • Holst, R., Kirby, J. and Magnusson, B. (1976) Sensitisation to tropical woods giving erythema multiforme-like eruptions. Contact Dermatitis 2: 295.
  • Irvine FR (1961) Woody Plants of Ghana. With special reference to their uses. London: Oxford University Press [doi] [WorldCat] [url] [url-2]
  • Koch, G., Magnusson, B. and Nyguist, G. (1971) Contact allergy to medicaments and materials used in dentistry. II. Sensitivity to eugenol and colophony. Odontol. Rev. 22: 275.
  • Loewenfeld, W. (1932) Ekzematose Uberempfindlichkeit gegen Eukalyptusol. Derm. Wschr. 95: 1281.
  • Lowry, J.B. (1973) A new constituent of biogenetic, pharmacological and historical interest from Melaleuca caieputi oil. Nature 241: 61.
  • Mabberley DJ (1987) The Plant-Book. A portable dictionary of the higher plants. Cambridge: Cambridge University Press
  • MacPherson, J. (1923) Dermatitis from eucalyptus trees. Med. J. Austr. 2: 265.
  • MacPherson, J. (1925) The toxicology of eucalyptus oil. Med. J. Australia 2: 108.
  • Maiden JH (1909b) On some plants which cause inflammation or irritation of the skin. Part II. Agricultural Gazette of New South Wales 20(12): 1073-1082 [url] [url-2]
  • Maiden JH (1916) On some plants which cause irritation of the skin. Agricultural Gazette of New South Wales 27(1): 39
  • Maiden, J.H. (1919) Notes on Acacia, no. IV. J. Proc. Roy. Soc. New South Wales 53: 219-200 (whole paper 171-238 + plates).
  • Maiden JH (1921a) Plants which produce inflammation or irritation of the skin. Agricultural Gazette of New South Wales 32(3): 206 [url] [url-2]
  • Mair, K. (1968) Director, Royal Botanic Gardens, Sydney, Australia. Personal communication to J.C. Mitchell from records of the Herbarium.
  • Meneghini, C.L., Rantuccio, F. and Lomuto, M. (1971) Additives, vehicles and active drugs of topical medicaments as causes of delayed-type allergic dermatitis. Dermatologica 143: 137.
  • Morton JF (1962a) Ornamental plants with toxic and/or irritant properties. II. Proceedings of the Florida State Horticultural Society 75: 484-491 [url] [url-2]
  • Morton, J.F. (1971) Plants Poisonous to People in Florida and other warm areas. Miami, Florida. Hurricane House Publishers, Inc.
  • Nasution, D., Klokke, A.H. and Nater, J.P. (1973) A survey of occupational dermatoses in Indonesia. Berufsdermatosen 21: 215.
  • Opdyke DLJ (1975) Fragrance raw materials monographs. Eugenol. Food and Cosmetics Toxicology 13(5): 545-547 [doi] [url] [pmid]
  • Schmid, R. (1972) A resolution of the Eugenia - Syzygium controversy. Amer. J. Bot. 59: 423.
  • Sézary, A. and Horowitz, A. (1935) Intolérance cutanée (eczéma artificiel) au goménol. Bull. Soc. Franc. Derm. Syph. 42: 425.
  • Silvers, S.H. (1939) Stomatitis and dermatitis venenata with purpura resulting from Oil of Cloves and Oil of Cassia. Dental Items Interest 61: 649.
  • Simons RDGP (1953) Jungle-dermatitis (dermatoses caused by tropical plants and woods). In: Simons RDGP (Ed.) Handbook of Tropical Dermatology and Medical Mycology. Vol. 2. pp. 1444-1452. Amsterdam: Elsevier Publishing Co.
  • Sternberg, L. (1937) Contact dermatitis. J. Allergy 8: 185.
  • Stone, H. (1921) A Textbook of Wood. London, Rider.
  • Stuart M (1979) Reference section. In: Stuart M (Ed.) The Encyclopedia of Herbs and Herbalism, pp. 141-283. London: Orbis Publishing [WorldCat] [url]
  • Walsh, F.B. (1957) Clinical Neuro-Ophthalmology. Baltimore. Williams and Wilkins.
  • Watt JM, Breyer-Brandwijk MG (1962) The Medicinal and Poisonous Plants of Southern and Eastern Africa. Being an account of their medicinal and other uses, chemical composition, pharmacological effects and toxicology in man and animal, 2nd edn. Edinburgh: E & S Livingstone [doi] [WorldCat] [url] [url-2]
  • White JC (1887) Dermatitis Venenata: an account of the action of external irritants upon the skin. Boston: Cupples and Hurd [doi] [WorldCat] [url] [url-2]
  • Willis JC (1973) A Dictionary of the Flowering Plants and Ferns, 8th edn. (Revised by Airy Shaw HK). Cambridge: Cambridge University Press [WorldCat]
  • Woeber K, Krombach M (1969) Zur Frage der Sensibilisierung durch ätherische Öle (Vorläufige Mitteilung). [Sensitization from volatile oils (Preliminary report)]. Berufsdermatosen 17(6): 320-326 [pmid]
  • Woods B, Calnan CD (1976) Toxic woods. British Journal of Dermatology 95(Suppl 13): 1-97 [doi] [url] [url-2] [pmid]
  • Zakon SJ, Goldberg AL, Kahn JB (1947) Lipstick cheilitis. A common dermatosis: report of thirty-two cases. Archives of Dermatology and Syphilology 56(4): 499-505 [doi] [url]

Richard J. Schmidt

[Valid HTML 4.01!]

[2D-QR coded url]