Night-blooming cereus is the common name referring to a large number of flowering ceroid cacti that bloom at night. The flowers are short lived, and some of these species, such as Selenicereus grandiflorus, bloom only once a year, for a single night. Other names for one or more cacti with this habit are princess of the night, Honolulu queen (for Hylocereus undatus), Christ in the manger, dama de noche and queen of the night. It is often confused with the genus Epiphyllum.
Selenicereus grandiflorus Hylocereus undatus