Oosi elumichai (Citrus aurantiifolia)

Oosi elumichai is Citrus aurantiifolia — the small, thin-skinned, seedy lime of a street glass and a pickle. Hindi kagzi nimbu is the same fruit. It is not the grocery lemon (C. limon), not a sweet lime, and not a detox. Tamil elumichai names both sour citrus. English keeps lime and lemon apart, and so does this site.

Botanical name: Citrus aurantiifolia (Christm.) Swingle
Family: Rutaceae
Tamil: Oosi elumichai
Hindi: Kagzi nimbu
Sanskrit: Nimbūka
Parts used: Fruit, Juice, Rind
Habit: Thorny citrus; the article is a small, thin-skinned, very sour green fruit
Last updated: 2026-10-30

How to recognise Oosi elumichai

Swingle published the combination. The family is Rutaceae. It is a small, very thorny tree: winged petioles, gland-dotted leaves, scented flowers, and a round to slightly oval fruit, usually green to yellow-green, with a thin rind, many seeds, and a sharp, floral sour juice.

The thin rind and small size are the kitchen test against a grocery lemon. A thick-skinned oblong yellow fruit is usually C. limon. A sweeter, thicker “mosambi” is a different citrus.

Tamil oosi elumichai, Hindi kagzi nimbu and English key lime are this heading. Persian lime (C. × latifolia) is a larger, usually seedless cousin sold as “lime” in some cities.

Kew treats the key lime as a cultivated hybrid in the Citrus complex, sometimes written Citrus × aurantiifolia.

Persian lime is seedless and a little larger.

C. limon is the lemon page.

Leaves of some Citrus season rice. A leaf is not a fruit, and curry leaf is Murraya.

Flowers are scented. A scentless blossom on a different tree is a reason to look at the fruit.

Traditional use of Oosi elumichai

South Asian food

Juice, pickle and a squeeze on a snack are cuisine.

Tamil, Hindi and wider kitchen practice

Household

A squeeze in water is a household drink. A drink is not a detox product.

Household practice

Modern notes on Oosi elumichai

Citric acid and rind oil are why the fruit tastes as it does. A squeeze and a capsule are not interchangeable.

The practical modern issue is lemon and lime under one Tamil word, and Persian lime sold as key lime.

Oosi elumichai safety

Culinary juice and pickle are the ordinary exposures. The juice is very acidic. Teeth and reflux notice that.

Rind oil can bother skin in the sun in some people. Essential oil is not a fruit.

Ecology and sourcing

It is a grafted or seedling orchard crop.

Related plants

Also in Rutaceae

Questions about Oosi elumichai

Is Oosi elumichai the same as lemon?

No. Lemon is Citrus limon.

What is the Tamil name used here?

Oosi elumichai — knowing that many shops say only elumichai.

Is Persian lime Oosi elumichai plant?

Usually no. Persian lime is a seedless hybrid sold as “lime” in some cities. This heading is the seedy key lime.

Sources

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.