Crown flower (Calotropis spp) is a large shrub or small tree from the Apocynaceae family. Calotropis gigantea and C. procera are the two most common species in the genus.
All parts of the plant contain a white milky sap (latex) which is toxic. The components within the sap are cardiac glycosides, calotropin, uscharin, calotoxin, and gigantin. If ingested, it can be fatal to birds. If the sap gets in their eye, it can cause severe corneal damage and possible blindness.