was first collected on the south-east coast of Tasmania in 1792-93 by
Jacques-Julien Houton de Labillardiere
(1755-1834) and described by him in 1799. He was a distinguished French botanist who accompanied Bruny D'Entrecasteaux on the expedition in La Recherche and L'Esperance in 1791-94 in search of their missing compatriot, La Perouse. The two ships of the expedition led by La Perouse landed at Botany Bay on 26 January 1788. They departed six weeks later and forty years elapsed before their fate was established by the discovery of wreckage at Santa Cruz, north of the New Hebrides. Labillardiere was a keen collector of plants and animals and also recorded detailed accounts of the appearance and customs of the Australian Aboriginals he observed. His plant specimens are now housed in the Museum of Florence.
now includes several subspecies of which
is the Tasmanian emblem. The generic name
is derived from the Greek 'eu', meaning 'well', and 'kalypto', meaning 'to cover, as with a lid', referring to the operculum, a cap-like structure which protects the stamens in the bud and is shed when the flower opens. The operculum is a distinguishing feature of all species of
. The specific name
, from the Latin meaning 'ball-like' or 'spherical', refers to the shape of the fruit. The genus
numbers about 800 species which are widely distributed in Australia, with a few species occurring in some of the islands to the north. It belongs to the family Myrtaceae, which is widespread in Australia and tropical regions of the Americas.
Tasmanian Blue Gum is a tall, straight tree growing to 70 metres in height and 2 metres in trunk diameter under favourable conditions. The rough, deeply furrowed, grey bark is persistent at the base of the trunk but above this level it is shed in strips leaving the branches and the greater length of the trunk smooth-barked. The broad juvenile leaves, borne in opposite pairs on square stems, are about 6 to 15 cm long and covered with a blue-grey, waxy bloom. This is the origin of the common name 'blue gum'. The mature leaves are narrow, sickle-shaped and dark shining green. They are arranged alternately on rounded stems and range from 15 to 35 cm in length. The buds are top-shaped, ribbed and warty and have a flattened operculum bearing a central knob. The cream flowers are borne singly in the leaf axils and produce copious nectar which tends to yield a strongly flavoured honey. The woody fruits range from 1.5 to 2.5 cm in diameter. Numerous small seeds are shed through valves which open on the top of the fruit.
occurs in tall open forest in south-eastern Tasmania and to a lesser extent along the eastern coast of the State. It also occurs on King and Flinders Islands in Bass Strait. Outside Tasmania it is confined to Wilson's Promontory and the Cape Otway district in southern Victoria. The climate throughout its range is cool to mild, with wet winters and reliable summer rainfall. Within parts of its range, light frosts and snowfalls occur.
Tasmanian Blue Gum is protected in conservation areas such as Maria Island National Park, Freycinet National Park, Tasman Arch Nature Reserve and St Mary's Pass Nature Reserve. Outside State reserves it occurs in reserves managed by the Department of Lands and the Forestry Commission. Both authorities have regulations prohibiting the taking of native flora from Crown Land and State forests respectively without prior permission of the managing authority.
Being a very tall evergreen tree Tasmanian Blue Gum is unsuitable for cultivation in the average home garden but it can be recommended as a handsome subject for parks and large gardens in regions which do not experience severe frosts. It is easily propagated from seeds. In subtropical horticulture it has enjoyed popularity as a bedding plant, with freshly raised seedlings being planted each year. Its horticultural value lies in the unusual effect achieved by the colour and form of the juvenile foliage. It is grown successfully in large gardens in Cornwall, where the cool to mild, damp climate is favourable.
The flowers are usually inaccessible and so they are seldom available for indoor decoration. The large blue-grey juvenile leaves are ideal as backing material in floral arrangements in which an unusual colour effect and bold form are desired. Either fresh or dried foliage may be used. Both emit the distinctive eucalyptus fragrance so evocative of the Australian bush.
Tasmanian Blue Gum yields pale, hard and durable timber which is used in Australia for poles, piles and sleepers. The species has been widely planted in New Zealand, South Africa, South America, California, India and Mediterranean countries, in farm windbreak, forestry and ornamental plantations. Among the qualities admired overseas are its rapidity of growth, straightness of trunk, strength of wood and adaptability to a range of sites. Originally overseas plantations supplied antiseptic oil, fuel, telegraph poles, mine props and construction timber. In addition they now provide pulpwood for paper and rayon manufacture. It has also contributed to the drainage of swamps in malarial localities in central Africa, Italy and Turkey. Before the role of the malarial mosquito in spreading the disease was understood, there was a superstitious belief that the leaves of the Blue Gum released a magical essence which purified the air of fever germs. In reality the benefit is derived from the loss of suitable breeding sites for mosquitoes, brought about by the capacity of the trees to evaporate water from the swampy ground.
Tasmanian Blue Gum is so abundant in coastal areas of California that many people assume it is a native species. In recent years concern has been expressed that it appears to be becoming naturalised. Studies show that there is a tendency for it to spread from plantations by seed dispersal along drainage lines but it is doubtful that it will ever become troublesome.
It was featured on a 15 cent stamp [
] issued on 10 July 1968 as part of a set of six stamps depicting State floral emblems. The stamp was designed by Dorothy Thornhill.
Although Tasmanian Blue Gum is the official floral emblem it seems to be seldom used for either official or popular purposes. This neglect may be due in part to the fact that, while it is a handsome tree of considerable economic importance, it is not as familiar to many Tasmanians as other indigenous species.
The armorial bearings of Tasmania include hops and apples, crops of considerable value to the State. The soubriquet, Apple Isle, is frequently used in tourist promotion and the apple is featured on a wide range of souvenirs.
A handsome ornamental shade, most widely planted of the subtropical/eucalypts. Grown for firewood in India (C.S.I.R., 1948 1976). This is one of the best eucalypts for pulp production. The timber is used for carpentry, construction, fences, piles, platforms, plywood, poles, sheds, and stations, tool handles, veneer, etc. Essential oil, widely used in cough drops, is antiseptic, rubefacient, and stimulant (Morton, 1981). A type of kino extracted from the tree in Argentina. Eucalyptus hybrid 'Mysore' is a promising source of pinenes, which are used in synthetic camphor, pine oil, terpineol, and in dry cleaning fluids, solvents, and cheap deodorants (Verma et al., 1978). The leaves have proven antibiotic acitivty. Their decoction is used for repelling insects and vermin (Morton, 1981). Africans use finely powdered bark as an insect dust. Mexicans chew the leaves to strengthen the gums. Said to be a good honey plant, Portuguese bee farmers like to raise their bees near this eucalyptus.
Reported to be anodyne, antiperiodic, antiphlogistic, antiseptic, astringent, deodorant, diaphoretic, expectorant, febrifuge, hemostat, inhalant, insect repellant, rubefacient, sedative yet stimulant, suppurative, and vermifuge, the bluegum eucalyptus is a folk remedy for abscess, arthritis, asthma, boils, bronchitis, burns, cancer, catarrh, cold, cough, croup, cystitia, diabetes, diptheria, dysentery, dyspepsia, fever, flu, grippe, inflammation, laryngitis, leprosy, malaria, miasma, phthisis, rhinitis, sores, sorethroat, spasms, tuberculosis, tumors, vaginitis, wounds, and worms (Watt and Breyer-Brandwijk, 1962; Duke and Wain, 1981; List and Horhammer, 19691979; Morton, 1981). Venezuelans take leaf decoction for cheat airments or colds, inhaling the vapors or drinking the decoction. Guatemalans use the leafy shoots for coughs and grippe, Jamaicans put the leaves in the bed, the bath, or the teapot for colds and fever. Cubans use the essential oil for bronchitis, bladder and liver infections, lung ailments, malaria, and stomach trouble. Mexicans chew the fresh leaves to strengthen the gums. Mexicans also use the leaf decoction as a vaginal douche. They argue that daily drinking of the leaf infusion can reverse diabetes in 8 days. Leaves are placed in the bath for rheumatism (Morton, 1981). Homeopaths use the plant for bronchitis, colds, flu, laryngitis, and rheumatism. In Asia, the leaf oil, clearly poisonous in large quantities, is regarded as anesthetic, antibiotic, antiperiodic, expectorant, febrifuge, and vermifuge, and it is used for asthma, bronchitis, influenza, and tuberculosis (Perry, 1980). In Australila, the leaves of the bluegum are still widely used as a household remedy in the treatment of many diseases and minor complaints. In Britain and Europe the essential oil, which is powerfully antiseptic, was given for fevers and febrile conditions, for pulmonary tuberculosis, and was applied or inhaled for relieving asthma, bronchitis, sorethroat, croup, whooping-cough, scarlet fever, and even diptheria and typhoid. The dried leaves were also smoked like cigarettes for asthma while the oil in the form of an aperitif was taken as a digestive (Brooker et al., 1981). Europeans in Africa and Africans themselves may wear the leaf in the hat or place it around the residence as a flu preventative. It is also regarded as a malaria preventitive. African herbalists believe the root is purgative.
Leaves contain 7080% eucalyptol (cineol). Also includes terpineol, sesquiterpene alcohols, aliphatic aldehydes, isoamyl alcohol, ethanol, and terpenes (Morton, 1981). Tannin is not so copious in the leaves as of many other
species. The kino, containing 28.7% kino-tannin and 47.9% catechin contains the very antibiotic citriodorol (Watt and Bryer-Brandwijk, 1962). Verma et al. (1978) found 20.2%
-pinene, and only 16.8% cineole in the cv 'Mysore'. Fresh leaves contain caffeic and gallic acids, dry leaves, ferulic and gentisic (Boukef et al., 1976), and quercetol, quercitrine, rutin, and a mixture of quercetol hyperoside and glaucoside. N-titriacontan-16, 18-dione was identified as the compound responsible for antioxidant activity in the leaf wax (Osawa and Namik, 1981).
In large doses, oil of eucalyptus, like so many essential oils has caused fatalities from intestinal irritation (Morton,1981). Death is reported from ingestion of 424 ml of essential oils, but recoveries are also reported for the same amount. Symptoms include gastroenteric burning and irritation, nausea, vomiting, diarrhea, oxygen deficiency, ,weakness, dizziness, stupor, difficult respiration, delirium, paralysis, convulsions, and death, usually due to respiratory failure (Duke, 1984b). Reported to cause contact dermatitis (Brooker et al, 1981). Sensitive persons may develop urticaria from handling the foliage and other parts of the plant (Watt and Bryer- Brandwijk, 1962).
Evergreen tree 4070 m tall with straight massive trunk 0.62 m in diameter with narrow, irregular crown of large branches and drooping aromatic, camphoraceous foliage. Root system deep and spreading. Bark smoothish, mottled gray, brown, and greenish or bluish, peeling in long strips, at base becoming gray, rough and shaggy, thick, and finely furrowed; inner bark light yellow within thin green layer. Leaves alternate, drooping on flattened yellowish petioles 1.54 cm long, narrowly lanceolate, 1030 cm long, 2.55 cm wide, mostly curved, acuminate at tip, acute at base, entire, glabrous, thick, leathery, with fine straight veins and vein inside marlin, shiny dark green on both surfaces. Flowers 1 (rarely 23), at leaf base, more than 5 cm across, the very numerous, white stamens ca 12 mm long. Buds top-shaped, 1215 mm long, 1225 mm wide. Stamens many, threadlike, white, anthers oblong opening in broad slits with round gland. Pistil with inferior 35-celled ovary and long stout style. Capsules single at leaf base, broadly top-shaped or rounded, 11.5 cm long, 22.5 cm wide, 4-angled, warty. Seeds many, irregularly elliptical, 23 mm long, dull black (Little, 1983).
The most extensively planted eucalypt species in the world...a total of 800,000 ha in dozens of countries...About half the world's plantation area is in Portugal and Spain (Little, 1983). Also cultivated in California, Arizona, and Hawaii.
Ranging from Cool Temperate Moist to Wet through Subtropical Dry to Moist Forest Life Zones, bluegum eucalyptus is reported to tolerate annual precipitation of 8 to 16 dm and annual temperature of ca 16 to 20°C. Major successes have been in mild temperate climates and in cool highlands. Elsewhere it fails (NAS, 1980a).
Propagated by seed and basket transplants ca 6 mos old. No seed treatment is required. Fresh seeds germinate well but deteriorate rapidly. The tree is readily established, easily reproducing from self-sown seed. In California, seed collections from a single tree exhibit wide variation (280%) in germinative capacity after a 30-day germination period (Ag. Handbook 450). Seedlings like the adults are susceptible to drought, fire, and frost. Grasses need to be weeded, as the tree does not compete well with grasses (NAS, 1980a). Tree grows rapidly and coppices readily (reaching a meter or more in a few months).
Annual wood production of 1030 m
has been reported from sites in Italy, Peru, Portugal, and Spain (NAS, 1980a). Verma et al (1978) estimated essential oil yields between ca 40 and 45 kg/ha from 68 MT green leaves. Completely dry leaves contain 1.27% oil in the cv 'Mysore'. The Wealth of India suggests 30 MT biomass/ha/yr in the Nilgiris (C.S.I.R., 19481976).
About 30 MT/ha biomass are reported. Verma et al. (1978) calculated little more than 7 MT leaves per hectare, green, or 68 MT for the cv 'Mysore', 34 MT dry leaves. In his compilation, Cannell (1982) cites data on trees 9.5 years old, spaced at 2,196 trees/ha. The stem wood on a DM basis weighed 1958 MT/ha, the stem bark 511, the branches 2.65.5, the foliage 4.06.7, for a total standing aerial biomass of 35110 MT/ha. The CAI (current annual increment) of stem wood was 2.97.7 m
/ha/yr, stem bark 0.71.5, branches 0.50.7, foliage 2.6ca 6 for a total aerial CAI of 6.715.6 MT/ha/yr, the low figures representing unfertilized trees, the high reflecting ca 200 kg/ha N and 90 kg/ha P. These data were taken at Victoria, Australia (38°20'S, 146°20'E, elev. 150 m). The wood burns freely, leaving little ash, and carbonizes easily, making good charcoal. With calorific value of 4,800 kcal/kg, the heavy wood (sp. grav. 0.81.0) is widely used for fuelwood and charcoal (NAS, 1980). Even the dead leaves and fallen bark are highly flammable. The charcoal is used for producer gas plants (C.S.I.R., 19481976). Cromer and Williams (Austr. J. Bot. 30:265. 1982) report that it took 9.5 years to accumulate 30 MT/ha biomass unfertilized, but only 4 years in heavily fertilized plots.
This plant can be weedy or invasive according to the authoritative sources noted below.This plant may be known by one or more common names in different places, and some are listed above. Click on an acronym to view each weed list, or click here for a composite list of
Weeds of the U.S.
Using these photos:
A variety of organizations and individuals have contributed photographs to CalPhotos. Please follow the usage guidelines provided with each image. Use and copyright information, as well as other details about the photo such as the date and the location, are available by clicking on the
link under the thumbnail. See also:
Using the Photos in CalPhotos