Tasmanian Blue Gum
E. globulus in Hawaii.
E. globulus in Hawaii.
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Rosids
Order: Myrtales
Family: Myrtaceae
Genus: Eucalyptus
Species: E. globulus
Binomial name
Eucalyptus globulus
Labill.

The Tasmanian Blue Gum, Southern Blue Gum or Blue Gum, is an evergreen tree, one of the most widely cultivated trees native to Australia. They typically grow from 30 to 55 m (98 to 180 ft) tall. The tallest currently known specimen in Tasmania is 90.7 m tall.[1] There are historical claims of even taller trees, the tallest being 101 m (330 ft)[2]. The natural distribution of the species includes Tasmania and southern Victoria. There are also isolated occurrences on King Island and Flinders Island in Bass Strait and on the summit of the You Yangs.

Contents

Habit

The bark shreds often, peeling in large strips. The broad juvenile leaves are borne in opposite pairs on square stems. They are about 6 to 15 cm long and covered with a blue-grey, waxy bloom, which 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 (cap on the flower bud) bearing a central knob. The cream-colored flowers are borne singly in the leaf axils and produce copious nectar that yields a strongly flavored honey. The fruits are woody and range from 1.5 to 2.5 cm in diameter. Numerous small seeds are shed through valves (numbering between 3 and 6 per fruit) which open on the top of the fruit. It produces roots throughout the soil profile, rooting several feet deep in some soils. They do not form taproots.

The Tasmanian Blue Gum was proclaimed as the floral emblem of Tasmania on 27 November 1962. The species name is from the Latin globulus, a little button, referring to the shape of the operculum.

Uses

Timber and Fuelwood

Blue gum is renown as a fast growing timber tree. It comprises 65% of all plantation hardwood in Australia with approximately 4,500 km² planted.[3] The tree is widely cultivated elsewhere in the world. It is primarily planted as a pulpwood, and also as an important fuelwood in many countries. It has poor lumber qualities due to growth stress problems, but can be used in construction, fence posts and poles. [4]

Essential Oil

The leaves are steam distilled to extract eucalyptus oil. E.globulus is the primary source of global eucalyptus oil production, with China being the largest commercial producer.[5][6] The oil has therapeutic, perfumery, flavoring, antimicrobial and biopesticide properties.[7] [8] [9] [10] Oil yield ranges from 1.0-2.4% (fresh weight), with cineole being the major isolate. E.globulus oil has established itself internationally because it is virtually phellandrene free, a necessary characteristic for internal pharmaceutical use. [11]In 1870, Cloez, identified and ascribed the name "eucalyptol" - now more often called cineole - to the dominant portion of E. globulus oil.[12]

Herb Tea

Blue gum leaves are used as a therapeutic herbal tea.[13]

Honey

Blue gum flowers are considered a good source of nectar and pollen for bees.

Environmental Weed

It was introduced to California in the mid 1800s and is prominent in many parks in San Francisco and throughout the state, where it is currently considered to be an invasive species due to its ability to quickly spread and displace native plant communities[14].

Related species

Many botanists treat The Tasmanian Blue Gum as a subspecies of a broader species concept. This broader E. globulus includes the following subspecies:

  • E. globulus subsp. bicostata = E. bicostata - Southern Blue Gum, Eurabbie, Victorian Blue Gum
  • E. globulus subsp. globulus = E. globulus - Tasmanian Blue Gum
  • E. globulus subsp. maidenii= E. maidenii - Maiden's Gum
  • E. globulus subsp. pseudoglobulus = E. pseudoglobulus - Gippsland Blue Gum, Victorian Eurabbie

The broader E. globulus concept is supported by Royal Botanic Gardens, Melbourne [15] and the Tasmanian Herbarium [16], but not by Royal Botanic Gardens, Sydney [17] where the four taxa are considered distinct species.

References

  1. ^ Giant Trees Consultative Committee
  2. ^ Lewin, D. W. 1906: The Eucalypti Hardwood Timbers of Tasmania. [1]
  3. ^ Australia's Plantations 2006. Bureau of Rural Sciences. Retrieved on 2007-01-24. 
  4. ^ Index of Species Information, Eucalyptus globulus [2]
  5. ^ Edited by Boland,D.J., Brophy, J.J., and A.P.N. House, Eucalyptus Leaf Oils - Use, Chemistry, Distillation and Marketing, Inkata Press, 1991, p4.
  6. ^ Eucalyptus Oil, FAO Corporate Document Repository [3]
  7. ^ Eucalyptus globulus Monograph, Australian Naturopathic Network [4]
  8. ^ Herbal Monograph: Eucalyptus globulus, Himlaya Healthcare [5]
  9. ^ Eucalyptus globulus, Association of Societies for Growing Australian Plants (ASGAP)[6]
  10. ^ Young-Cheol Yang, Han-Young Choi, Won-Sil Choi, J. M. Clark, and Young-Joon Ahn, Ovicidal and Adulticidal Activity of Eucalyptus globulus Leaf Oil Terpenoids against Pediculus humanus capitis (Anoplura: Pediculidae), J. Agric. Food Chem., 52 (9), 2507 -2511, 2004.[7]
  11. ^ Edited by Boland,D.J., Brophy, J.J., and A.P.N. House, Eucalyptus Leaf Oils - Use, Chemistry, Distillation and Marketing, Inkata Press, 1991, p3., & pp78-82.
  12. ^ Boland, D.J., Brophy, J.J., and A.P.N. House, Eucalyptus Leaf Oils, 1991, p6 ISBN 0-909605-69-6
  13. ^ Eucalyptus Globulus Labill Leaf Pieces Tea [8]
  14. ^ California Invasive Plant Council (Cal-IPC) Invasive Plant Inventory 2006 http://www.cal-ipc.org/ip/inventory/pdf/Inventory2006.pdf
  15. ^ "A Census of the Vascular Plants of Victoria". Royal Botanic Gardens, Melbourne.
  16. ^ "The Tasmanian Herbarium".
  17. ^ "Flora of New South Wales". Royal Botanic Gardens, Sydney.

External links

Shedding bark

Flower bud

Fruit

3, 4, 5 & 6 valved fruits

Illustration
Wikimedia Commons has media related to:
Wikispecies
Wikispecies has information related to:


v • d • e
Floral emblems of Australia and its states and territories
National: Acacia pycnantha (Golden Wattle)
ACT Wahlenbergia gloriosa (Royal Bluebell) • NSW Telopea speciosissima (New South Wales Waratah) • NT Gossypium sturtianum (Sturt's Desert Rose)
QLD Dendrobium phalaenopsis (Cooktown Orchid) • SA Swainsona formosa (Sturt's Desert Pea) • TAS Eucalyptus globulus (Tasmanian Blue Gum)
VIC Epacris impressa (Common Heath) • WA Anigozanthos manglesii (Red and Green Kangaroo Paw)
Retrieved from "http://en.wikipedia.org/wiki/Eucalyptus_globulus"


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