Eucalyptus citriodora
What's the taxonomical classification of Eucalyptus citriodora?
Eucalyptus citriodora belongs to the kingdom Plantae and is classified under the phylum Streptophyta. Within this lineage, it is categorized under the class Equisetopsida and the subclass Magnoliidae. Moving down the taxonomic hierarchy, it is placed in the order Myrtales and belongs to the family Myrtaceae. Finally, the plant is identified by its genus, Eucalyptus, and its specific species name, citriodora.
| Taxonomic Rank | Classification |
|---|---|
| Kingdom | Plantae |
| Phylum | Streptophyta |
| Class | Equisetopsida |
| Subclass | Magnoliidae |
| Order | Myrtales |
| Family | Myrtaceae |
| Genus | Eucalyptus |
| Species | citriodora |
What are the morphological characteristics of this plant?
Eucalyptus citriodora has lanceolate, bright green leaves that measure up to 15 centimeters in length and are characterized by a distinct lemon-scented oil. The foliage is typically arranged oppositely on the branches during its juvenile stage before transitioning to an alternate pattern as the tree matures. Its bark is smooth and light in color, often shedding in thin flakes to reveal a pale surface underneath. The tree produces small, white, clustered flowers that emerge from woody buds. These floral structures eventually give way to hard, cup-shaped fruits known as capsules.
What is the geographical distribution of this plant?
This plant is native to the eastern coastal regions of Australia, specifically spanning from the northern parts of Queensland down through New South Wales. It thrives primarily in subtropical and temperate climates where moisture is relatively consistent. Within these areas, the species is frequently found in well-drained soils along forest margins and creek lines. While its natural range is restricted to these specific Australian states, it has been widely introduced to other parts of the world for its fragrant essential oils. Consequently, cultivated populations can now be found in various Mediterranean-style climates across different continents.
How is this plant cultivated?
This plant, Eucalyptus citriodora, requires well-drained sandy or loamy soils and full sunlight to thrive in subtropical or tropical climates.
It is best propagated through semi-hardwood cuttings rather than seeds to ensure the preservation of its essential oil properties. During the early stages of growth, consistent moisture is necessary, but the mature tree is highly drought-tolerant once established. Farmers typically harvest the leaves periodically to extract citronella oil through steam distillation.
Proper spacing between saplings is essential to prevent overcrowding and to facilitate efficient airflow.
What parts of this plant are used medicinally?
This plant Eucalyptus citriodora provides medicinal benefits through its leaves, bark, and kino. The leaves are most commonly harvested to extract essential oils like citronellal for treating skin conditions and respiratory issues. Bark extracts are sometimes utilized for their potential anti-inflammatory and antimicrobial properties. The kino, which is a resinous substance, is traditionally used to treat wounds and digestive ailments. Each of these components offers unique chemical compounds that contribute to the species' therapeutic value.
According to a study published by "Metabolites", the ethanol extract of Eucalyptus citriodora leaf is used as a remedy for illnesses including diabetes. This extract induced insulin secretion in a concentration-dependent manner with effects similar to 1 uM glucagon-like peptide 1. In vivo evaluations using high-fat-fed rats showed that the extract improved glucose tolerance and plasma insulin while attenuating plasma DPP-IV and inducing active GLP-1 (7-36) levels. The study identified possible phytoconstituent responsibilities including Rhodomyrtosone B, Quercetin-3-O-beta-D-glucopyranoside, rhodomyrtosone E, and quercitroside. These findings suggest that Eucalyptus citriodora could serve as an adjunct nutritional supplement to manage type 2 diabetes.
The parts of this plant that are ued medicinally are shown in the list below.
- leaf
- bark
- kino
What traditional systems uses this plant?
This plant, Eucalyptus citriodora, has been historically utilized across various global cultures for its potent antimicrobial and anti-inflammatory properties. In many traditional herbal practices, the essential oils extracted from its leaves are applied topically to treat skin ailments or inhaled to alleviate respiratory congestion. Within the specific context of Togo traditional medicine, practitioners often incorporate the plant into decoctions to manage fever and digestive issues. This botanical species is also valued in many indigenous systems for its ability to act as a natural insect repellent. These diverse historical applications highlight the long-standing medicinal importance of the plant in both regional and international folk medicine.
The hystorical systems that uses this plant are shown in the list below.
- Togo traditional medicine
What are the pharmacological activities of Eucalyptus citriodora?
This plant has antibacterial, antimicrobial, antifungal, anti-inflammatory, and antioxidant pharmacological activities driven by its rich essential oil content. The presence of compounds like citronellal allows it to effectively inhibit the growth of various pathogenic bacteria and fungi. These antimicrobial properties make it a valuable resource in combating diverse microbial infections. Furthermore, its ability to neutralize free radicals provides significant antioxidant protection for cells. The plant also demonstrates anti-inflammatory effects that help reduce swelling and pain in biological tissues.
According to a study published by "Cellular and molecular biology (Noisy-le-Grand, France)", the essential oil from Eucalyptus citriodora cultivated in northeastern Brazil contains 12 compounds, including citronellal at 65.45%, citronellol at 14.87%, isopulegol at 11.80%, and citronellyl acetate at 2.51%. While the oil did not show significant activity against tested strains with a MIC > 1000 µg mL-1, it demonstrated a capacity to modify the resistance of S. aureus and E. coli strains to various antimicrobial agents. The study found that synergistic effects were obtained through the oil, resulting in reduced MIC values for all tested antibiotics. Consequently, Eucalyptus citriodora shows antimicrobial and β-lactam optimizing potential, offering an alternative for using drugs at concentrations lower than those typically indicated against resistant strains.
The primary pharmacological activities of this plant are shown in the list below.
- antibacterial
- antifungal
- antimicrobial
- antioxidant
- anti-inflammatory
What medicinal compounds this plant contains?
This plant contains the medicinal compounds citronellal, citronellol, citronellyl acetate, eucalyptol, and citronyl acetate. These specific chemical constituents contribute to the potent antimicrobial and insect-repellent properties of the leaves. Citronellal and citronellol are primary components responsible for the characteristic citrus scent and biological activity. The presence of citronellyl acetate and citronyl acetate further enhances the oil's therapeutic complexity. Additionally, eucalyptol provides significant anti-inflammatory benefits when utilized in medicinal applications.
According to a study published by "Planta medica", five Eucalyptus citriodora leaves from the same tree over different months yielded very similar analyses. The volatile constituents extracted from these leaves included 72.9-80.5% citronellal and 3.5-5.4% citronellol. Additionally, the analysis showed 1.0-3.8% citronellyl acetate was present. The plant also contained 9.2-11.8% caryophyllene and 1.4-1.7% bicyclogermacrene.
The primary medicinal compounds of this plant are shown in the list below.
- citronellal
- citronellol
- citronellyl acetate
- eucalyptol
- citronellyl acetate
What health conditions is this plant used for?
This plant is used for treating respiratory ailments such as asthma, managing the coughing reflex, improving airflow in the nasal tract, and combating fungal infections. Its natural essential oils act as expectorants to help clear mucus from the lungs and airways. By reducing inflammation, it can soothe the irritation associated with chronic coughing. The aromatic compounds also help open up nasal passages to make breathing much easier during congestion. Additionally, its antimicrobial properties provide an effective defense against various fungal infections.
According to a study published by "African journal of traditional, complementary, and alternative medicines : AJTCAM", Eucalyptus citriodora Hook. is identified as one of the most important species for curing asthma. This plant is part of a group of 98 plant species belonging to 54 families identified in the survey. The study was conducted from January to June 2015 with 121 traditional healers, including 92 males and 29 females. These healers use such plants to treat clinical manifestations such as wheezing (91.74%), difficulty as speaking or coughing (73.55%), dyspnea (66.94%), dry cough (52.89%), and sweating and increased heart rate (52.07%).
The main health conditions this plant is used for are shown in the list below.
- airflow in the nasal tract
- asthma
- coughing reflex
- respiratory ailments
- fungal infections
What are the herbal preparations of this plant?
This plant is Eucalyptus citriodora, which is utilized to create medicinal preparations including essential oil, ethanol extract, and leaf extracts. The essential oil is primarily obtained through steam distillation and is valued for its high concentration of citronellal. Ethanol extracts are produced by soaking the plant material in alcohol to isolate specific bioactive compounds. Leaf extracts can be prepared through various aqueous or solvent-based methods for topical or internal use. These diverse preparations allow for the targeted application of the plant's therapeutic properties in different medical contexts.
According to a study published by "Foodborne pathogens and disease", Eucalyptus citriodora essential oil obtained by microwave-assisted hydrodistillation contains major components of citronellal at 30.67% and citronellol at 19.14%. This medicinal plant serves as an antiseptic agent with antibacterial efficacy demonstrated by minimum inhibitory concentration values ranging from 5.75-92 µg/mL and minimum bactericidal concentration values ranging from 11.5-184 µg/mL. The oil effectively inhibited biofilm formation and significantly inhibited adhesion on a 304 L stainless-steel surface. Investigations using UV-visible analysis at 260 nm showed significant leakage of cytoplasmic substances including proteins, DNA, and RNA due to devastation of the bacterial cell membrane.
The main herbal preparations of this plant are shown in the list below.
- Essential oil
- Ethanol extract
- Leaf extracts
What side effects this plant can have?
This plant can cause a wide range of adverse health effects including skin irritation, allergic reactions, nausea, vomiting, stomach cramps, dizziness, confusion, and seizures. When applied topically, the essential oils may trigger contact dermatitis or sensitive skin responses. Ingestion of the plant can lead to severe gastrointestinal distress characterized by painful stomach cramps and emesis. Systemic toxicity often impacts the central nervous system, manifesting as lightheadedness or mental disorientation. In extreme cases of poisoning, the chemical compounds can provoke life-threatening neurological events such as seizures.
The main side effects this plant can have are shown in the list below.
- Skin irritation
- Allergic reaction
- Nausea
- Vomiting
- Stomach cramps
- Dizziness
- Confusion
- Seizures
What herbs are paired with Eucalyptus citriodora?
This plant, Eucalyptus citriodora, pairs most effectively with aromatic herbs like rosemary, lemon balm, thyme, and peppermint to enhance its bright, lemony scent profile.
The citrusy high notes of the lemon eucalyptus provide a sharp contrast to the woody and earthy undertones found in rosemary or thyme. Incorporating lemon balm can amplify the plant's natural citronella-like qualities for a more cohesive floral aroma. Using peppermint alongside it creates a refreshing, cooling effect that works well in aromatherapy or garden landscaping.
These combinations balance the intensity of the eucalyptus oils with softer, complementary botanical scents.