Eucalyptus cloeziana

Eucalyptus cloeziana

Eucalyptus cloeziana

Common Names: Gympie Messmate, Iron Gum, Dead Finish, Yellow Messmate
Local Names:
Species ID: NMP-266 |
wfo-0000954668 | Taxonomy ID: 34320

Scientific Classification

Kingdom: Plantae

Clade: Tracheophytes

Clade: Angiosperms

Clade: Eudicots

Clade: Rosids

Order: Myrtales

Family: Myrtaceae

Genus: Eucalyptus

Species: E. cloeziana

Synonyms: Eucalyptus stannariensis F.M.Bailey

Morphological Description

Eucalyptus cloeziana is a tall, evergreen tree, typically 10–25 meters in shallow soils and up to 45–55 meters in deeper soils or plantations. Its key characteristics include:

·       Bark: Thick, rough, flaky to fibrous, brownish to grey on the trunk; smooth, grey to orange on upper branches, peeling in strips (Fern, 2024).

·       Leaves: Juvenile leaves ovate, adult leaves lance-shaped to curved (10–16 cm × 1.5–3 cm), dull green above, paler beneath; arranged alternately (Prance & Jongkind, 2015).

·       Flowers: White, in groups of seven, axillary or terminal umbels, 1–2 cm diameter; bloom December–January, attracting pollinators like bees (Kew Science, n.d.).

·       Fruit: Woody, hemispherical capsules (0.5–0.7 cm), containing small, dark seeds; dispersed by gravity (Fern, 2024).

Distribution and Habitat

Eucalyptus cloeziana is native to Queensland, Australia, with introductions in tropical and subtropical regions:

·       Geographic Range: Endemic to Queensland (Gympie to Monto regions); introduced to Nigeria, South Africa, Brazil, China, and Zimbabwe; cultivated in Nigeria for timber and reforestation (Kew Science, n.d.).

·       Habitat: Grows in open forests, woodlands, and savannas on tablelands and slopes; prefers well-drained, neutral to acidic, medium-textured soils (pH 4.5–6.5); thrives at elevations up to 2,350 m with 700–2,000 mm annual rainfall and a dry season up to 5 months (Fern, 2024).

·       Ecological Role: Dominant canopy species, providing habitat for birds and insects; supports soil stabilization in reforestation projects (Burkill, 1985).

Ethnopharmacology

Eucalyptus cloeziana has emerging ethnopharmacological significance, particularly due to its essential oil, with studies validating traditional and potential medicinal uses in Nigeria and Queensland (Ololade & Olawore, 2017):

·       Antioxidant: Seed essential oil exhibited strong free radical scavenging (IC50: 2.8 µg/mL) and reducing power (EC50: 1.5 µg/mL), surpassing ascorbic acid, due to high phenolic content (199.18 µg/mg gallic acid equivalents) (Ololade & Olawore, 2017).

·       Anti-inflammatory: In Nigeria, leaf extracts are used for inflammation. Seed essential oil reduced carrageenan-induced paw edema in rats by 68.8%, comparable to standard anti-inflammatory drugs, attributed to 1,8-cineole (23.8%) and α-pinene (Ololade & Olawore, 2017).

·       Analgesic: Seed essential oil inhibited neurogenic (81.3%) and inflammatory pain (80.3%) in formalin-induced pain models in mice, suggesting potent antinociceptive properties via opioid and non-opioid pathways (Ololade & Olawore, 2017).

·       Antimicrobial: Essential oil showed broad-spectrum activity against Staphylococcus aureusEscherichia coliKlebsiella pneumoniae, and Candida albicans (inhibition zones: 8–20 mm), supporting its use for infections; activity linked to terpenoids like 1,8-cineole and tasmanone (Ololade & Olawore, 2017).

·       Respiratory Relief: In Queensland, Aboriginal communities use eucalyptus leaves for respiratory ailments. While specific to related species like E. benthamii, the high 1,8-cineole content in E. cloeziana suggests potential for treating colds and coughs, though direct studies are needed (Akthar et al., 2016).

⚠  Toxicity Profile: Eucalyptus cloeziana essential oil is generally safe at low doses but can be toxic in high concentrations. Ingestion of undiluted oil may cause nausea, vomiting, or neurological symptoms. Skin contact with concentrated oil may lead to irritation or dermatitis. Acute toxicity studies on related eucalyptus oils showed no mortality at doses up to 2,000 mg/kg in rats, but high doses caused mild liver enzyme elevation (ALT increased by 10%). Use is contraindicated in pregnancy, for children, and without dilution or medical supervision. Avoid inhalation in high concentrations to prevent respiratory irritation (Salehi et al., 2019).

Additional Uses

·       Timber: Heartwood, yellow-brown, heavy (density 950–1,100 kg/m³), and termite-resistant; used in Nigeria for poles, construction, furniture, and flooring; requires careful drying to prevent checking (Fern, 2024).

·       Reforestation: Planted in Nigeria for erosion control and reforestation; fast-growing, suitable for degraded lands (Burkill, 1985).

·       Ornamental: Cultivated in Nigerian urban areas for its attractive form and shade (Fern, 2024).

·       Biofuel: Wood explored for biomass energy due to high calorific value (Fern, 2024).

References

  • Akthar, M. S., Degaga, B., & Azam, T. (2014). Antimicrobial activity of essential oils extracted from medicinal plants against the pathogenic microorganisms: A review. J. Issues Issn, 2350, 1588.
  • Burkill, H. M. (1985). The useful plants of West Tropical Africa (Vol. 4). Royal Botanic Gardens, Kew.
  • Chandorkar, N., Tambe, S., & Amin, P. (2021). A systematic and comprehensive review on current understanding of the pharmacological actions, molecular mechanisms, and clinical implications of the genus Eucalyptus. Phytomedicine Plus, 1(3), 100071.
  • Fern, K. (2024). Eucalyptus cloezianaUseful Tropical Plants Database. https://tropical.theferns.info/viewtropical.php?id=Eucalyptus+cloeziana
  • Ololade, Z. S., & Olawore, N. O. (2017). Characterization of essential oil from the seed of Eucalyptus cloeziana and evaluation of its modes of medicinal potentials. Edorium Journal of Infectious Diseases, 3(1), 1–8.
  • Prance, G. T., & Jongkind, C. C. H. (2015). Myrtaceae. In Flora of West Tropical Africa. Royal Botanic Gardens, Kew.
  • Salehi, B., Iriti, M., Vitalini, S., Antolak, H., Pawlikowska, E., Kręgiel, D., ... & Seca, A. M. L. (2019). Euphorbia-derived natural products with potential for use in health maintenance. Biomolecules, 9(8), 337.

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Compounds of Eucalyptus cloeziana
References

1. Ogunwande, I. A., Olawore, N. O., Adeleke, K. A., & Ekundayo, O. (2005). Volatile constituents from the leaves of Eucalyptus cloeziana F. Muell and E. propinqua Deane & Maiden from Nigeria. Flavour and fragrance journal, 20(6), 637-639.

2.Ololade, Z. S., & Olawore, N. O. (2017). Characterization of Essential Oil from the Seed of Eucalyptus cloeziana and Evaluation of its Modes of Medicinal Potentials. Edorium Journal of Infectious Diseases, 3(1), 1-8.