Each flower consists of five pointed petals and a small "crown" rising from the center which holds the stamens.

The aestivation found in calotropis is valvate i.e. sepals or petals in a whorl just touch one another at the margin, without overlapping.

The pollen are in a structure named pollinia which is attached to a glandular, adhesive disc at the stigmatic angle (translator mechanism).

Flower-buds ovoid, angled, Calyx lobes 5, divided to the base, white, ovate; corolla broadly rotate, valvate, lobes 5, deltoid ovate, reflexed, coronate-appendages broad, obtusely 2-auricled below the rounded apex which is lower than the staminal-column.

Stamens 5, anthers short with membranous appendages, inflexed over the depressed apex of the pentagonal stigma.

[5] They were favored by the Hawaiian Queen Liliuokalani, who considered them a symbol of royalty and wore them strung into leis.

Calotropis yields a durable fiber (commercially known as bowstring of India) useful for ropes, carpets, fishing nets, and sewing thread.

[10] Extracts of plant parts such as root, stem, and leaf affect germination and seedling vigor of many agricultural crops.

The milky juice of Calotropis procera was used against arthritis, cancer, and as an antidote for snake bite.

The milky latex sap of Calotropis gigantea is a known cause of toxic keratoconjunctivitis and reversible vision loss.

Crown flower keratitis is a rare condition and is usually the result of accidental ocular exposure to the sap.

Damage (poisoning) of the cornea endothelium results in corneal stromal edema and decreased visual acuity.

When taken orally, the juice produces an acrid, bitter taste and burning pain in throat and stomach, salivation, stomatitis, vomiting, diarrhea, dilated pupils, tetanic convulsions, collapse and death.

[25] In the Paushya chapter of the Adi Parva portion of the Indian epic Mahabharata, a disciple of the rishi Ayoda-Daumya named Upamanya goes blind by eating the leaves of the plant which in Sanskrit is called arka.

However, in India, among the general public, it is the belief that akada (arka) is a poisonous plant and can make people intoxicated.

Lord Shiva is offered akada along with dhatura (botanically: Datura metel) (extremely toxic) flowers on auspicious days.