Calotropis is a genus of plants that produce milky sap hence also commonly called milkweed. It is considered a common weed in some parts of the world. The flowers are fragrant and are often used in making ‘floral tassels’ in some mainland Southeast Asian cultures. Fibers of these plants are called mudar or mader. The plant is known as aak in Ayurveda. The latex is said to have a mercury-like effects on the human body, and is some times referred to as vegetable mercury and is used in place of mercury in aphrodisiacs. It is used variously but sometimes leaves are fried in oil for medicinal purposes.
The calotropis plant is usually found in abandoned farmland. Cattle often stay away from the plant because of its unpleasant taste and due to presence of Cardiac Glucosides in its sap.
Root bark has Digitalis like effect on the heart, but was earlier used as a substitute of ipecacuanha.
It is a poisonous plant; calotropin, a compound in the latex, is more toxic than strychnine. Calotropin is similar in structure to two cardiac glycosides which are responsible for the cytotoxicity of Apocynum cannabinum L. Extracts of flower of Calotropis procera has shown a strong cytotoxic activity in the patients of colorectal cancer. They are harmful to the eyes.
Calotropis gigantea (Crown flower) is a species of Calotropis, native to Indonesia, Malaysia, Philippines, Thailand, Sri Lanka, India and China.
It is a large shrub growing to 4 m tall. It has clusters of waxy flowers that are either white or lavender in colour. Each flower consists of five pointedpetals and a small, elegant “crown” rising from the centre, which holds the stamens. The plant has oval, light green leaves and milky stem.
The flowers last long, and in Thailand they are used in various floral arrangements. They were also supposed to be popular with the HawaiianQueen Liliuokalani, who considered them as symbol of royalty and wore them strung into leis. In India, the plant is common in the compounds oftemples. The fruit is a follicle and when dry, seed dispersal is by wind. This plant plays host to a variety of insects and butterflies.