Calotropis gigantea

Calotropis gigantea (crown flower) is a species of Calotropis native to Cambodia, Indonesia, Malaysia, the Philippines, Thailand, Sri Lanka, India, China, Pakistan, Nepal, Booc Booc in Somalia and tropical Africa. 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 '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 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. It is the host plant for Hawaii's non-migratory monarch 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 in a structure named pollinia which is attached to a glandular, adhesive disc at the stigmatic angle (translator mechanism). These sticky discs get attached to the legs of visiting bees that pull out pollinia when a bee moves away. When such a bee visits another flower, this flower might be pollinated by the pollinium. The flowers are long lasting, and in Thailand they are used in floral arrangements. The extract of flowers and leaves has shown hypoglycemic effect in preclinical studies. They were favored by the Hawaiian Queen Liliuokalani, who considered them a symbol of royalty and wore them strung into leis. 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. According to Shivpuran (Hindu religion) the madar flower/crown flower is very much liked by Lord Shiva; therefore the crown flower and its garland are offered to Lord Shiva for peace, prosperity and stability in society. The Crown flower is also one of the major parts of the nine astrological trees (Navagrah tree). 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 as stuffing. Crown flower cotton can also be used to make a pillow. A fermented mixture of Calotropis and salt is used to remove the hair from goat skins for production of nari leather and from sheep skins to make leather which is much used for inexpensive book binding. Fungicidal which is far effective than oinmentand insecticidal properties of Calotropis have been reported. 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, আকন (akon) in Assamese, আকন্দ (aakonda) in Bengali, erukku (എരുക്ക്) in Malayalam, yakka (ಯಕ್ಕ) in Kannada, jilledu (జిల్లేడు) in Telugu, ark (अर्क) in Sanskrit, and Ak (اَک) in Urdu. Allelopathic effects of Calotropis on different agricultural crops have been well studied. Extracts of plant parts such as root, stem, and leaf affect germination and seedling vigor of many agricultural crops. However, extracts of Calotropis failed to produce any detrimental effects on weeds such as Chenopodium album, Melilotus alba, Melilotus indica, Sphaeranthus indicus, and Phalaris minor.