As in the closely related genus Selenicereus (to which the familiar queen of the night belongs), the large flowers of the ca. 12 species of Hylocereus are only open for a single night.
The up to 12 cm long tasty fruits of Hylocereus undatus are highly prized in Central America, where they are known as «pitaya». They are sometimes marketed in Europe as «dragon fruit». Hylocereus cacti range from southern Mexico and the Caribbean to northern South America and require tropical temperatures in order to thrive.