Eucalyptus radiata A.Cunn. ex DC.

Last updated: 20 Apr 2016

Scientific Name

Eucalyptus radiata A.Cunn. ex DC.

Synonyms

Eucalyptus amygdalina var. radiata (A. Cunn. ex DC.) Benth., Eucalyptus australiana R.T.Baker & H.G.Sm., Eucalyptus australiana var. latifolia R.T.Baker & H.G.Sm., Eucalyptus phellandra R.T.Baker & G.G.Sm., Eucalyptus radiata var. australiana (R.T.Baker & H.G.Sm.) Blakely, Eucalyptus radiata subsp. radiata, Eucalyptus radiata var. subexserta Blakely. [1]

Vernacular Name

English Common peppermint, narrow-leaf peppermint, Robertson’s peppermint, narrow-leaf peppermint gum [2]

Geographical Distributions

Eucalyptus radiata can be found in New South Wales, Australia. This plant is largely restricted to the mid to upper sections of the Forth River catchment. It occurs on basalt, granite, quartzite, sediments and metamorphic substrates and inhabits forest types from dry to wet sclerophyll. [3]

Botanical Description

E. radiata is a member of Myrtaceae family. It is a medium-sized tree growing up to 35 m. [2]

The bark is grey-brown and relatively fibrous. The stems of seedling and juvenile plants are sometimes covered with raised reddish oil glands that are rough to the touch. [3]

The young leaves are soft and flexible, green, stalkless, and arranged in opposite pairs along the stem. They have pointed tips and are broad rather than narrow linear in shape. The mature leaves are lance-shaped, shortly stalked, flexible, olive green and alternately arranged along the stem. When dried, the venation of both young and mature leaves often becomes reddish. [3]

The fruit is a small bud, which is shortly stalked and club-like in shape with a slightly pointed tip. There are between 8-16 buds in clusters on each flowering part. [3]

Cultivation

No documentation.

Chemical Constituent

E. radiata leaves extract has been reported to contain oxides (e.g. 1.8 cineol, caryophyllene oxide); monoterpenes (e.g. α-pinene, ß-pinene, l-limonene, myrcene, ρ-cymene); alcohols (e.g. α-terpinol, geraniol, borneol, linalool); aldehydes (e.g. myrtenal, citronellal, geranial, neral). [4]

Plant Part Used

Leaves [5]

Traditional Use

E. radiata has been traditionally used as antibacterial, anticatarrhal, anti-infectious, anti-inflammatory, antiviral, and expectorant. [4]

Preclinical Data

Pharmacology

Antibacterial activity

E. radiata oil extract that contain 1,8-cineole and α-terpineol has been demonstrated a potent antibacterial activity against a few bacterial strains. [6][7][8]

Repellent activity

Acetone extract of E. radiata leaves has been reported to exhibit repellent activity against mosquito (Aedes albopictus). Results obtained show that among Eucalyptus oil used, E. radiata possessed the most potent activity compare to others. [9]

In other experiment, the extract of E. radiata oil also has been showed to exhibit fumigant activity against Japanese termite (Reticulitermes speratus Kolbe). [10]

Toxicity

No documentation.

Clinical Data

No documentation.

Line drawing

No documentation.

References

  1. The Plant List. Ver1.1. Eucalyptus radiata A. Cunn. ex DC. [homepage on the Internet] c2013 [updated 2012 Mar 23; cited 2016 Apr 20]. Available from: http://www.theplantlist.org/tpl1.1/record/kew-73756.
  2. U.S National Plant Germplasm System. Eucalyptus radiata. No date [cited 2016 Apr 27]. Available from: https://npgsweb.ars-grin.gov/gringlobal/taxonomydetail.aspx?id=16007.
  3. Treated Flora of Tasmania. Eucalyptus radiata. Department of Primary Industries Parks, Water and Environment. No date [cited 2016 Apr 27]. Available from: http://dpipwe.tas.gov.au/Documents/Eucalyptus-radiata-subsp-radiata-notesheet.pdf.
  4. Higley C, Higley A. Reference guide for essential oils. USA: Abundant Health, 2006; p. 69-70.
  5. Lis-Balchin M. Aromatherapy science: A guide for healthcare professionals. London: Pharmaceutical Press, 2006; p. 185.
  6. Inouye S, Takizawa T, Yamaguchi H. Antibacterail activity of essential oils and their major constituents against respiratory tract pathogens by gaseous contact. J Antimicrob Chemother. 2001;47(5):565-573.
  7. Takarada K, Kimizuka R, Takahashi N, Honma K, Okuda K, Kato T. A comparison of the antibacterial efficacies of essential oils against oral pathogens. Oral Microbiol Immunol. 2004;19(1):61-64.
  8. Watson RR, Preedy V.  Botanical medicine in clinical practice. UK: CABI, 2009; p. 166.
  9. Cutler HG, Cutler SJ. Biologically active natural products. Great Britain: Taylor and Francis, 1999; p. 138.
  10. Park IK, Shin SC. Fumigant activity of plant essential oils and components from garlic (Allium sativum) and clove bud (Eugenia caryophyllata) oils against the Japenese termite (Reticulitermes speratus Kolbe). J Agric Food Chem. 2005;53(11):4388-4392.