Calotropis procera is a species of flowering plant in the family Apocynaceae that is native to Northern and Tropical Africa, Western Asia, South Asia and Indochina. It typically reaches a height between 6 feet (1.8 m) to 8 feet (2.4 m), and rarely to as high as 15 feet (4.6 m), and grows in sunny to partly-shaded habitats such as disturbed and overgrazed lands, rangeland, roadsides, river flats and coastal dunes. Its green fruits contain a toxic milky sap that is extremely bitter and turns into a latex-like substance, which is resistant to soap.

Calotropis gigantea, the crown flower, is a species of Calotropis native to Cambodia, Vietnam, Bangladesh, Indonesia, Malaysia, Thailand, Sri Lanka, India, China, Pakistan, and Nepal.