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 pollinia.
See also: Beli Bunga, Flowers Auckland, Gift Pakistan