Eucalyptus globulus

taxobox
name = Tasmanian Blue Gum

---

image_caption = "E. globulus" in Hawaii.
regnum = Plantae
unranked_divisio = Angiosperms
unranked_classis = Eudicots
unranked_ordo = Rosids
ordo = Myrtales
familia = Myrtaceae
genus = "Eucalyptus"
species = "E. globulus"
binomial = "Eucalyptus globulus"
binomial_authority = Labill.
range_
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. [ [http://www.gianttrees.com.au Giant Trees Consultative Committee ] ] There are historical claims of even taller trees, the tallest being 101 m (330 ft) [Lewin, D. W. 1906: The Eucalypti Hardwood Timbers of Tasmania. [http://www.archive.org/details/eucalyptihardwoo00lewiuoft] ] . 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.

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. [cite book |url=http://www.affashop.gov.au/PdfFiles/plantations_100dpi.pdf |title=Australia's Plantations 2006 |publisher=Bureau of Rural Sciences |accessdate=2007-01-24] 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. [Index of Species Information, Eucalyptus globulus [http://www.na.fs.fed.us/spfo/pubs/silvics_manual/volume_2/eucalyptus/globulus.htm] ]

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. [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.] [ Eucalyptus Oil, FAO Corporate Document Repository [http://www.fao.org/docrep/v5350e/v5350e07.htm] ] The oil has therapeutic, perfumery, flavoring, antimicrobial and biopesticide properties. [ Eucalyptus globulus Monograph, Australian Naturopathic Network [http://www.ann.com.au/herbs/Monographs/eucalypt.htm] ] [ Herbal Monograph: Eucalyptus globulus, Himlaya Healthcare [http://www.himalayahealthcare.com/herbfinder/h_eucalyptus.htm] ] [Eucalyptus globulus, Association of Societies for Growing Australian Plants (ASGAP) [http://asgap.org.au/e-glo.html] ] [ 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. [http://pubs.acs.org/cgi-bin/abstract.cgi/jafcau/2004/52/i09/abs/jf0354803.html] ] 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. [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.] In 1870, Cloez, identified and ascribed the name "eucalyptol" - now more often called cineole - to the dominant portion of "E. globulus" oil. [ Boland, D.J., Brophy, J.J., and A.P.N. House, "Eucalyptus Leaf Oils", 1991, p6 ISBN 0-909605-69-6]

Herb Tea

Blue gum leaves are used as a therapeutic herbal tea. [ Eucalyptus Globulus Labill Leaf Pieces Tea [http://www.21food.com/showroom/24442/product/Eucalyptus-Globulus-Labill-Leaf-Pieces-Tea.html] ]

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 [California Invasive Plant Council (Cal-IPC) Invasive Plant Inventory 2006 http://www.cal-ipc.org/ip/inventory/pdf/Inventory2006.pdf] .

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 EurabbieThe broader "E. globulus" concept is supported by Royal Botanic Gardens, Melbourne [cite web | url = http://www.rbg.vic.gov.au/dbpages/viclist/cd/ | title = A Census of the Vascular Plants of Victoria | publisher = Royal Botanic Gardens, Melbourne] and the Tasmanian Herbarium [cite web | url = http://www.tmag.tas.gov.au/Herbarium/Herbarium2.htm | title = The Tasmanian Herbarium] , but not by Royal Botanic Gardens, Sydney [cite web | url = http://plantnet.rbgsyd.nsw.gov.au/floraonline.htm | title = Flora of New South Wales | publisher = Royal Botanic Gardens, Sydney] where the four taxa are considered distinct species.

References

External links

* [http://www.fs.fed.us/database/feis/plants/tree/eucglo/botanical_and_ecological_characteristics.html Botanical characteristics of "Eucalyptus globulus"]
* [http://www.anbg.gov.au/emblems/tas.emblem.html Australian National Botanic Gardens]
* [http://git-forestry-blog.blogspot.com/2007/12/citizen-labillardieres-heritage.html Chronology of the discovery of "Eucalyptus globulus"] Iglesias Trabado, Gustavo (2007). In: [http://git-forestry-blog.blogspot.com/ EUCALYPTOLOGICS]