Backhousia citriodora
Lemon myrtle
Generally recognised as safeOther names: Lemon myrtle, Lemon-scented ironwood
Lemon myrtle—subtropical east; lemon aroma in food.
Evergreen shrub with elliptic aromatic leaves and white flowers.
- Family
- Myrtaceae
- Plant type
- Shrub / tree
What the safety levels mean (expand legend)
- Generally recognised as safe. Often a common herb with reasonable harvest and use; still read the specific warnings on the card.
- Information. Primarily informational — details in the text and warnings below matter most.
- Caution. Needs extra care (dose, duration, sensitive groups, interactions).
- Risky. Significant risks — verify sources, contraindications and professional guidance.
- Not for home experimentation. Not suitable to experiment with at home without knowledge and certainty.
- High risk for internal use. Particular risk with internal use (e.g. alkaloids); avoid prolonged or irresponsible dosing.
- Not specified. Level not filled in yet — rely on individual warnings and links below.
Photograph on Wikimedia Commons (CC BY-SA 3.0).
Plant habit
Quick overview
A practical summary; details are in the sections below.
- Safety grade
- Generally recognised as safe details
- Scientific sources on the card
- Yes — sources are listed with claims Science section
- When and what to harvest
- Leaf — January–December
- Processing methods
Herbal infusion (tea), Culinary use
All methods and recipes on the card- Topics and symptoms
Common cold — overall comfort, Digestion
Topics section, Symptoms overview
Identification and mix-ups
Leaf strongly lemon when crushed.
Possible mix-ups and risks
Similar myrtles by scent and site.
Similar herbs
- Lemongrass
Two unrelated plants with the same scent: both smell of citral, lemon myrtle carrying even more in its oil. Myrtle is a tough leathery tree leaf, lemongrass a grass stalk.
Topics and symptoms
More topics are in the symptoms and topics overview.
- Common cold — overall comfortAromatherapy· Traditional / cultural framing
- DigestionCulinary· Traditional / cultural framing
Geographic occurrence
Australia
Common (expected wild occurrence in the region)
Harvest
- LeafJanuary–December
celoročně
Region: AustraliaNotes: Leaves are harvested all year, mechanically from hedgerows on Queensland plantations; they dry in the shade at low temperature to preserve citral, which makes up to 90 % of the oil.
Storage
- Drying(Leaf)
Dried whole leaves keep 12–18 months in a closed container; ground leaf loses aroma within six months.
- Light:
- Out of light.
- Moisture:
- Protect from moisture.
Processing methods on this herb card
Infusion or brief extraction in hot water; usually without long boiling.
Full method description (from the catalogue)
In the narrow sense, "tea" often means an infusion: you pour water just off the boil over the dried plant matter and let it steep for a few minutes. Temperature, steep time, and the herb-to-water ratio change both flavour and what dissolves into the liquid.
Compared with a decoction, heat exposure is shorter and gentler; tender leaves and flowers are often better as an infusion than with prolonged simmering. For each herb, always follow the plant card for suitable plant part, preparation, and safety notes — general rules never replace species-level judgement.
Traditional context for this method: yes·Scientific context for this method: no
Cooking, baking, seasoning as food — general category without therapeutic claims.
Full method description (from the catalogue)
Culinary use covers herbs as ingredients in dishes, drinks, or spice mixes. This overview does not evaluate medicinal effects — only reminds you about species intent, allergies, and heat treatment where needed (e.g. some fruits or plant parts).
Combining with alcohol, sugar, or long cooking changes outcomes; verify culinary sources.
Traditional context for this method: yes·Scientific context for this method: no
Traditional / spiritual use
Kept separate from science — entries are cultural or symbolic, not medical advice.
Queen of the lemon herbs from Queensland's rainforests
General
Traditional useFolk useHerbal loreAboriginal people of subtropical Queensland, the Bundjalung and Gubbi Gubbi among them, used lemon myrtle leaves to flavour food, scent water and, crushed, on the skin; since the 1990s it has been the most successful herb of the Australian bushfood movement and is grown in hedgerows for its food-grade oil. A record of tradition, not effect.
- Form:
- list v kuchyni a k ovonění, bushfood
- Claim strength:
- Tradition
- Source note:
- Ethnobotany of subtropical Queensland; Southwell 2021 (history of use and cultivation).
Scientific notes
Each claim lists a study type and a source (URL or DOI) where available. Dose notes from the literature are informational only.
How to read evidence strength and study type labels
Labels summarise how the catalogue entry is tagged — they are not a medical verdict on efficacy. For every row, read the summary, limitations and source link.
Evidence strength
- Evidence level not specified
- The author did not grade the record; judge from the summary, limitations and source link.
- Narrative / orientational literature
- Descriptive or expert literature without controlled group comparison — context rather than proof of effect.
- Weak evidence
- Study or conclusion with major methodological limits; treat only as a pointer for further reading.
- Preliminary findings
- First or smaller studies — interesting direction, not the final word on efficacy or safety.
- Moderate strength of evidence
- Moderate strength by study design; sample and context limits still apply.
- Stronger evidence
- Stronger design or consistency of results within the study's stated limits.
- Review article
- A review summarises multiple sources; quality depends on review method and field.
Study type
- Narrative / expert text
- Expert text or overview without a classical study design.
- In vitro study
- Cell culture or test-tube experiment — does not show an effect in the body.
- Animal study
- Animal model — transfer to humans is not automatic.
- Observational study
- Observing groups without random treatment assignment; confounding is possible.
- Clinical trial
- Human clinical trial; sample size and control group matter.
- Randomised controlled trial
- Randomised controlled trials are among the stronger designs when well conducted.
- Review study
- A review aggregates multiple papers — quality depends on selection rules.
- Systematic review
- Systematic review with explicit search and selection methodology.
- Meta-analysis
- Statistical pooling of studies; outcome depends on input data and heterogeneity.
- Regulatory assessment / monograph (EMA, WHO…)
- Regulatory body summary for a herbal product — different context from a single RCT; often about products, not home tea.
- Expert monograph (herbal preparations)
- Structured literature summary for a plant or drug — quality depends on author and edition year.
The review reports that lemon myrtle oil contains 90 % or more citral, the highest of any known plant, and describes laboratory antimicrobial activity, use in foods and cosmetics, and safety limits for citral on skin.
Narrative / orientational literatureReview studyYear: 2021Limitations: A chemical and technological review; it gives no clinical data on health effects in humans.
Southwell I — Foods
Backhousia citriodora F. Muell. (Lemon Myrtle), an Unrivalled Source of Citral
Images
The main photo is in the card header. More images will appear here when available.
Safety
What the warning types mean
The type on each warning helps group themes — it does not replace the separate severity badge.
- Internal use
- Risks from swallowing, extracts, duration of use or concentration for internal use.
- Interactions / medicines
- Possible effect on medicines or concurrent treatment — check sources and a professional.
- Raw plant parts
- Raw, unripe or poorly prepared plant parts can be dangerous.
- Toxins and regulation
- Toxic constituents or regulated compounds (e.g. in distillates).
- Contact with the plant
- Skin or mucosa irritation from contact with fresh plant or sap.
- Allergy
- Allergic reactions, often linked to family sensitisation.
- Harvesting and contamination
- Contamination, species mix-ups or harvesting from unsuitable places.
- An oil of 90 % citral irritates skinLow severityContact with the plant
Lemon myrtle oil is almost pure citral, which undiluted irritates and sensitises skin (Southwell 2021 cites cosmetic limits); on skin only at low dilution, never internally. Leaf tea and cooking are not affected.