The WALA Plant Library
Night-Blooming Cereus, Queen of the Night

Synonyms for Night-Blooming Cereus, Queen of the Night: Large-flowered cactus, sweet-scented cactus, vanilla cactus
Scientific Name: Selenicereus grandiflorus L.
Family: Cactaceae (cactus family)

Description:

Lovers of the opera will inevitably be reminded of Mozart’s Magic Flute when they hear the name queen of the night. However, the queen of the night referred to here is not a vengeful queen who can reach the highest notes but a cactus, night-blooming cereus, that scales rock faces and walls with the aid of aerial roots and clinging spines, sometimes also using other plants for support. If the aerial roots come in contact with soil they become real roots and enable the cactus to form new, independent plants. The spines, which grow along the edges of the thin, four- to eight-edged, snaking branches, are actually nothing more than modified leaves. With this trick the cacti reduce their surface and thus reduce the amount of water evaporating from the leaves, where water loss is greatest.
But the leaves are not the only parts greatly reduced in cacti. The side shoots, too, are no longer recognisable as such but are transformed into small, felt-like cushions that sit directly on the surface of the branches. From these cushions, called areoles, grow not only the spines but also large flowers with a diameter of 15 to 27 centimetres, which contrast strongly with the otherwise rather scrawny appearance of the queen of the night. On the outside the flowers are brownish-yellow, but towards the centre the colour changes from pale yellow to white. These flowers are true queens of the night. They not only look look very impressive, with their crown of thorn-shaped petals that surrounds them like a radiating halo, but they also make their entrance in the night, or more precisely for one single night, when the flower opens completely and exhales an enchanting vanilla fragrance. Drawn by the perfume, nocturnal bats visit the flower to drink the nectar, incidentally ensuring pollination at the same time. The pollinated flowers develop tomato-sized, red to yellowish coloured fruits which are edible to humans and also much enjoyed by the bats.