Adathodai is Justicia adhatoda, the Malabar nut shrub whose leaves have been a South Asian cough herb for a very long time. Older packets say Adhatoda vasica. Kew and most modern lists treat Justicia adhatoda as the name to file.
- Botanical name
- Justicia adhatoda L.
- Family
- Acanthaceae
- Tamil
- Adathodai
- Hindi
- Adusa
- Sanskrit
- Vāsaka
- Parts used
- Leaves, Sometimes flowers and root
- Habit
- Evergreen shrub of South Asia
- Last updated
- 2026-10-30
How to recognise Adathodai
Linnaeus published Justicia adhatoda. The family is Acanthaceae, with nilavembu as a distant cousin. It is a shrub, not an annual: opposite leaves, large and lance-shaped, and white two-lipped flowers with darker streaks in dense spikes.
The older combination Adhatoda vasica still appears on Ayurvedic lists and on village signs. If you are writing a label today, use Justicia adhatoda and mention the synonym so older readers are not lost.
Tamil adathodai, Hindi adusa and Sanskrit vāsaka or vāsā are the usual names. The English “Malabar nut” is a colonial trade name, not a kitchen nut.
A crushed leaf has a strong, slightly fishy green smell that people in Tamil Nadu recognise from childhood decoctions. Smell is a clue, not a certificate.
It is planted on fences and waste ground across much of India. A shrub you can walk up to is easier to identify than a brown leaf powder.
The capsule splits to fling small seeds, so a neglected hedge becomes a thicket. That habit is why the plant is common near villages and why a leaf from the fence is more trustworthy than an export powder.
Nurses and grandmothers in Tamil Nadu often keep one bush “for cough.” Familiarity is not a monograph. Write the Latin name on a drying sheet if the leaf will leave the yard.
Traditional use of Adathodai
Siddha and Ayurveda
Leaf decoctions appear in both systems for cough and breath categories. Those are historical uses. They are not a modern licence to treat asthma or tuberculosis.
Siddha and Ayurvedic headings for vasaka / adathodai
Tamil household
Adathodai leaves are boiled in ordinary houses when a cough has gone on. Household use is the most common exposure and still needs a careful reader, not a slogan.
Tamil household practice
Modern notes on Adathodai
Quinazoline alkaloids (vasicine and related compounds) are the chemistry textbooks mention. Chemistry is not a clinical trial, and a boiled leaf is not an isolated alkaloid.
Because the synonym Adhatoda vasica is still everywhere, a literature search must use both names or it will lie by omission.
Leaf collected after the white spikes have gone over is not the same object as a spring flush. A good label gives the harvest month beside the accepted name.
Adathodai safety
Leaf decoctions can be harsh. Concentrated extracts and isolated alkaloids are not kitchen objects.
Pregnant people should not take vasaka preparations; traditional texts and later reviewers have treated the plant as something to avoid in pregnancy.
Do not give strong leaf preparations to infants.
Ecology and sourcing
The shrub is common and planted. Wild-harvest pressure is usually not the story; honest drying of leaf is.
A later lot, if any, should carry the accepted name and the harvest month. Leaves collected after flowering are not the same as a spring flush.
The shrub coppices. Cutting a few branches does not kill a hedge the way digging a wetland rhizome does. Honest drying and a name are the scarce things, not the plant.
Related plants
Also in Acanthaceae
Questions about Adathodai
Is Adhatoda vasica a different plant?
No. Adhatoda vasica is the older name still printed on many packets. The accepted name used here is Justicia adhatoda L.
What is the Tamil name of Justicia adhatoda?
Adathodai.
Sources
- Justicia adhatoda L. — Plants of the World Online, Kew (search) (accessed 2026)
- Wikidata item Q61022811 (Justicia adhatoda)
Educational page about a plant. It is not medical advice, not a diagnosis, and not an offer to sell. Traditional use is historical. If you need care, ask a licensed clinician. Questions: hello@meevamed.com.