Vellai erukku (Calotropis procera)

Aak, arka in Sanskrit, is the apple of Sodom or small crown flower, a grey-green milkweed shrub of dry, sandy country. Its leaves and flowers are offered to Shiva and Hanuman, and its pale, purple-tipped flowers are smaller than those of the giant milkweed, Calotropis gigantea. All parts are full of a white latex that is caustic to the eyes and poisonous to eat. Its balloon-like fruits release silky floss.

Botanical name: Calotropis procera (Aiton) W.T.Aiton
Family: Apocynaceae
Tamil: Vellai erukku
Hindi: Aak
Sanskrit: Arka
Parts used: Latex in lists, Leaves in lists
Habit: Dry-country milkweed with caustic latex and balloon-like fruit
Last updated: 2026-10-27

How to recognise Vellai erukku

It is a shrub or small tree, usually two to four metres, with corky bark and abundant milky latex.

The leaves are thick, waxy, grey-green and broadly oval, clasping the stem.

The flowers are pale lilac to white with purple tips, with petals held upright, and a central crown.

The fruit is a large, inflated, balloon-like pod that splits to release seeds with silky floss.

Giant milkweed has larger, spreading purple or white flowers.

Traditional use of Vellai erukku

Ritual

Aak leaves and flowers are offered to Shiva and woven into garlands for Hanuman.

Hindu ritual practice

Household

The floss is used for stuffing, and the stem bark yields a strong fibre for rope.

Indian village practice

Ayurveda

Arka is used in Ayurveda mostly externally, as warmed leaves on painful joints.

Ayurvedic practice

Modern notes on Vellai erukku

The latex contains cardenolides and protein-digesting enzymes that make it caustic.

Latex splashes are a common cause of eye injuries in rural India.

Caterpillars of the plain tiger butterfly feed on it and store its toxins.

Vellai erukku safety

Never put latex near the eyes or take any part by mouth. If latex enters the eye, rinse with running water for fifteen minutes and see a doctor.

Ecology and sourcing

It grows across dry Africa, Arabia and South Asia on sandy, disturbed ground.

Carpenter bees pollinate its flowers.

It spreads quickly on overgrazed land because animals avoid it.

Related plants

Also in Apocynaceae

Questions about Vellai erukku

Is aak poisonous?

Yes. Its latex is toxic and caustic.

How is Vellai erukku different from giant milkweed?

Its flowers are smaller, with upright petals.

Why is Vellai erukku offered to Shiva?

It is a traditional temple offering.

Which butterfly uses Vellai erukku?

The plain tiger.

What should I do if latex hits my eye?

Rinse well and see a doctor.

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.