Which flower is known as the 'Kadupul flower' and blooms only at night?

The flower known as the Kadupul flower that blooms at night is Epiphyllum oxypetalum. This cactus is also called the queen of the night, princess of the night, or Dutchman’s pipe cactus.

Epiphyllum oxypetalum is native to parts of Mexico and Central America. Unlike many familiar desert cacti, it usually grows as an epiphyte, using trees or other supports without taking nutrients from them. Its flattened stems produce large, white, strongly fragrant flowers that open after sunset.

The blooms are nocturnal and typically wilt before dawn, which gives the plant its dramatic reputation. Their timing and fragrance are associated with pollination by night-active animals, although the plant’s exact pollinators can vary by region. The flowers can reach roughly 20 centimeters in length and width.

The name night-blooming cereus is often applied loosely to this plant, but that can cause confusion. Epiphyllum oxypetalum is not closely related to the terrestrial Cereus species commonly called night-blooming cereuses. Kadupul is therefore a common name, while Epiphyllum oxypetalum is the canonical scientific answer.