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(L.) W.T.Aiton 1811 not (L.) R. Br. 1811
It is a large shrub growing to 4 m (13 ft) tall. It has clusters of waxy flowers that are either white or lavender in colour. Each flower consists of five pointed petals and a small, elegant "crown" rising from the centre, which holds the stamens. The plant has oval, light green leaves and milky stem. The latex of Calotropis gigantea contains cardiac glycosides, fatty acids, and calcium oxalate.
This plant plays host to a variety of insects and butterflies. Calotropis is an example of entomophily pollination (pollination by insects) and pollination is achieved with the help of bees. In Calotropis, gynostegium is present (formed by the fusion of stigma and androecium). The pollen are arranged in a structure named pollinia which are attached to a glandular, adhesive disc at the stigmatic angle (Translator Mechanism). These sticky discs get attached to the legs of visiting bees so that pollinia are pulled out when the bee moves away. When such a bee visits another flower, this flower gets pollinated by the sticky pollinium.
The flowers last long, and in Thailand they are used in various floral arrangements. They were also supposed to be popular with the Hawaiian Queen Liliuokalani, who considered them as symbol of royalty and wore them strung into leis. While in Cambodia, they are used in funerals to decorate the urn or sarcophagus and the interior of the house holding the funeral. The fruit is a follicle and when dry, seed dispersal is by wind. In Indonesia its flowers are called widuri.
In India, the plant is common in the compounds of temples and is known as Madar in Hindi: मदार. Its leaf (Marathi: rui) is one of the five leaves used in the Panch Pallava, a ritual assortment of five different leaves used as a totem by the Maratha culture in India.
It is known as වරා (waraa) in Sinhala.
||This section needs more medical references for verification or relies too heavily on primary sources. (January 2015)|
Calotropis is used as a traditional medicinal plant with unique properties.[full citation needed][full citation needed][full citation needed] Traditionally calotropis is used alone or with other medicinals (Caius 1986) to treat common disease such as fevers, rheumatism, indigestion, cough, cold, eczema, asthma, elephantiasis, nausea, vomiting, diarrhea. [full citation needed] According to Ayurveda, the dried whole plant is a good tonic, expectorant, depurative, and anthelmintic. The dried root bark is a substitute for ipecacuanha.[medical citation needed] The flowers are bitter, digestive, astringent, stomachic, anthelmintic, and tonic.[full citation needed][full citation needed][medical citation needed]
Calotropis yields a durable fiber (commercially known as Bowstring of India) useful for ropes, carpets, fishing nets, and sewing thread. Floss, obtained from seeds, is used for stuffing purposes. Fermented mixture of Calotropis and salt is used to remove the hair from goat skins for production of "nari leather" and of sheep skins to make leather which is much used for inexpensive book-binding (Singh et al. 1996). Fungicidal and insecticidal properties of Calotropis have been reported.Ganapathy and Narayanasamy 1993).
Allelopathic effects of Calotropis on different agricultural crops have been well studied. Extracts of different plant parts such as root, stem, and leaf affect germination and seedling vigor of many agricultural crops.[full citation needed][full citation needed] However, extracts of Calatropis failed to produce any detrimental effects on weeds such as Chenopodium album, Melilotus alba, Melilotus indica, Sphaeranthus indicus, and Phalaris minor.[full citation needed]
Calotropis is recognized as a poisonous plant in India and South Asia. The active principles are uscharin, calotoxin, calactin, and calotropin. The leaves and stem when incised yield thick milky juice. It is used as an arrow poison, cattle poison, rarely for suicide and homicide and mostly an accidental poison.
The milky latex sap of Calotropis gigantea is a known cause of toxic keratoconjunctivitis and reversible vision loss. "Crownflower keratitis" is a rare condition and is usually the result of accidental ocular exposure to the sap. During the process of making a Hawaiian lei flower necklace, touching the sap and then touching the ocular surface may result in Crownflower keratitis. Damage (poisoning) of the cornea endothelium results in corneal stromal edema and decreased visual acuity. Although there is some permanent damage to the corneal endothelium with decreased endothelial cell count and irregular shape, the remaining corneal endothelial cells usually recover with complete resolution of the corneal edema and a return to normal visual acuity. The condition is usually self-limited and resolves faster with topical steroids. The clinical course of this condition suggests that Calotropis is paradoxically relatively nontoxic to corneal epithelium and highly toxic to corneal endothelium. The painless clinical course may be related to anesthetic properties of Calotropis latex and relatively minor epithelial injury.
Signs and symptoms
Applied to the skin, it causes redness and vesication. 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. The fatal period is 6 to 12 hours. Treatment includes stomach wash, demulcents, and symptomatic treatment.[medical citation needed]
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 (extremely toxic) flowers on auspicious days.
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- Oudhia, P. (2002).Allelopathic potential of useful weed Calotropis gigantea R.Br: A review. In: Abstracts. Third World Congress on Allelopathy: Challenges for the New Millennium, National Institute for Agro-Environmental Sciences (NIAES), Tsukuba, Japan, Aug.26-30,2002:179.
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- Hani S. Al-Mezaine, Ali A. Al-Rajhi, Abdullah Al-Assiri, Michael D. Wagoner, Calotropis procera (ushaar) keratitis, American Journal of Ophthalmology, Volume 139, Issue 1, January 2005, Pages 199-202
|Wikimedia Commons has media related to Calotropis gigantea.|
- PIER - Calotropis gigantea
- Flowers of India - Crown flower
- Purdue University: Center for New Crops & Plant Products - Crown flower
- Dressler, S.; Schmidt, M. & Zizka, G. (2014). "Calotropis gigantea". African plants – a Photo Guide. Frankfurt/Main: Forschungsinstitut Senckenberg.