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Eucalyptus globulus Labill.

Myrtaceae
Eucalypt, Tasmanian bluegum

Source: James A. Duke. 1983. Handbook of Energy Crops. unpublished.

  1. Uses
  2. Folk Medicine
  3. Chemistry
  4. Toxicity
  5. Description
  6. Germplasm
  7. Distribution
  8. Ecology
  9. Cultivation
  10. Harvesting
  11. Yields and Economics
  12. Energy
  13. Biotic Factors
  14. References

Uses

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.

Folk Medicine

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, 1969–1979; 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.

Chemistry

Leaves contain 70–80% 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 Eucalyptus 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% a-pinene, 25.2% b-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).

Toxicity

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 4–24 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).

Description

Evergreen tree 40–70 m tall with straight massive trunk 0.6–2 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 1.5–4 cm long, narrowly lanceolate, 10–30 cm long, 2.5–5 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 2–3), at leaf base, more than 5 cm across, the very numerous, white stamens ca 12 mm long. Buds top-shaped, 12–15 mm long, 12–25 mm wide. Stamens many, threadlike, white, anthers oblong opening in broad slits with round gland. Pistil with inferior 3–5-celled ovary and long stout style. Capsules single at leaf base, broadly top-shaped or rounded, 1–1.5 cm long, 2–2.5 cm wide, 4-angled, warty. Seeds many, irregularly elliptical, 2–3 mm long, dull black (Little, 1983).

Germplasm

Reported from the Australian Center of Diversity, bluegum, or cvs thereof is reported to tolerate narrower extremes of temperature and soil than many of the more tropical species. (2n = 20, 22, 28)

Distribution

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.

Ecology

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).

Cultivation

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 (2–80%) 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).

Harvesting

Usually grown on rotations of 5–15 years. In India's Nilgiris, bluegum plantations are worked for fuel purposes on a 15-year coppice (C.S.I.R., 1948–1976).

Yields and Economics

Annual wood production of 10–30 m3 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 6–8 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., 1948–1976).

Energy

About 30 MT/ha biomass are reported. Verma et al. (1978) calculated little more than 7 MT leaves per hectare, green, or 6–8 MT for the cv 'Mysore', 3–4 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 19–58 MT/ha, the stem bark 5–11, the branches 2.6–5.5, the foliage 4.0–6.7, for a total standing aerial biomass of 35–110 MT/ha. The CAI (current annual increment) of stem wood was 2.9–7.7 m3/ha/yr, stem bark 0.7–1.5, branches 0.5–0.7, foliage 2.6–ca 6 for a total aerial CAI of 6.7–15.6 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. 0.8–1.0) 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., 1948–1976). 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.

Biotic Factors

Listed as affecting Eucalyptus globulus are the following: Actinopelte dryina, Armillaria mellea, Cercospora epicoccoides, C. eucalypti, Corticium salmonicolor, Cryptosporium eucalypti, Cytospora australiae, C. eucalyptina, Diaporthe medusaea, Didymosphaeria circinnans, Diplodia australiae, Fomes applanatus, F. scruposus, Fusarium oxysporum var. aurantiacum, Ganoderma lucidum, Harknessia uromycoides, Hendersonia eucalypticola, Laetiporus sulphureus, Macrophoma molleriana, Macrophomina phaseoli, Monochaetia desmazierii, Mycosphaerella molleriana, Pestalotia truncata, Pestalotiopsis funerea, Pezizella carneo-rosea, Pezizella oenotherae, Phellinus gilvus, Phyllostica extensa, Physalospora latitans, P. rhodina, P. suberumpens, Polyporus gilvus, P. hirsutus, P. schweinitzii, P. sulphureus, P. versicolor, Poria cocos, P. versipora, Sclerotinia fuckeliana, Septonema multiplex, Septosporium scyphophorum, Stereum hirsutum, and Valsa eucalypti (Ag. Handbook 165; Browne, 1968). Also listed in Browne (1968) are the following: Angiospermae: Dendrophthoe, neelgherensis, and Viscum album. Coleoptera: Gonipterus scutellatus, Paropsis obsoleta, Phoracantha semipunctata, and Triphocaris mastersi. Hemiptera: Ctenarytaina eucalypti and Eriococcus coriaceus. Hymenoptera: Rhinopeltella eucalypti. Lepidoptera: Metanastria hyrtaca, Mnesampela privata, and Spilonota macropetana. Foliage unpalatable to livestock. The oil rich wood is resistant to termites (NAS, 1980a).

References

Complete list of references for Duke, Handbook of Energy Crops
Last update Tuesday, January 6, 1998 by aw