Selenicereus grandiflorus
Selenicereus grandiflorus is a cactus species originating from the Antilles, Mexico and Central America. The species is commonly referred to as Nightblooming Cereus, Queen of the Night (though these two terms are also used for other species), Large-flowered Cactus, Sweet-Scented Cactus or Vanilla Cactus. The true species is extremely rare in cultivation. Most of the plants under this name belong to other species or hybrids.

# Common names
- Dutch: Koningin van de Nacht
- English: Queen of the Night, Night-blooming Cereus, Large-flowering Cactus, Sweet-scented Cactus, Vanilla Cactus, Large Blooming Cereus, Large flowered torch thistle
- French: reine de la nuit, princesse de la nuit, cierge a grande fleurs, vierge a grandes fleurs, Cierge rampant a grandes fleurs, Fleur d'amour
- German: Konigin der Nacht, Schlangencereus, Schlangenkaktus
- Italian: cacto grandifloro, regina della notte
- Portoguese: flor-de-baile, cardeiro trepador
- Spanish: Reina de las Flores, Reina Gigante, Cardon, Gigante, Organillo, Reina de la noche.
- Swedish: nattens drottning
- Danish: Nattens Dronning
- Romana: Antilele Olandeze

# Etymology
Grandiflorus (Lat.) = large flowered. When Carl von Linne descripted this cacti in 1753 it was the largest flowered species of cacti known. Paradoxally, are moderate in size compared with several other Selenicereus species.

# History
The first species to be brought into cultivation. Linne (Linnaeus) descripted it in 1753, but it was known long before. Records from Hortus Kewensis gives that the species was grown at Royal Gardens at Hampton Court before 1700. There has been doubt about which plant was available to Linne when he drew up his description, but this is solved and both the plates on this side show the authentic species.

# Origin and habitat
Greater Antilles (Cuba, Cayman Islands, Jamaica & Haiti), Mexico, Guatemala, Belize, Honduras and Nicaragua. Climbing on trees and on rocks. -700m alt. Very variable, especially in Jamaica, stems with slightly wavy to strongly knobby margins occurs in the same plant. Much confused in cultivation. Many species of Selenicereus should be reduced to synonyms of subspecies of this species, differing merely in degree rather than in kind.

# Cultivation
An easily cultivated, fast growing epiphyte or lithophytic plant. Needs a compost containing plenty of humus and sufficient moisture in summer. Should not be kept under 5oC (41oF) in winter. Perform best if grown in full sun. Extra light in the early spring will stimulate budding. Flowers in late spring or early summer.

# Description
Stems scandent, clambering or sprawling, branching, sometimes forming tangles, producing aerial roots, stiff, to 10m long or more, (10)15-25(-30)mm thick; ribs (4-)7-8(-10), low, less so on older branches, separated by broad, rounded intervals, slightly wavy to strongly knobby; areoles small, wool white or greyish white, internodes (6-)12-20mm; spines 5-18, to 4,5-12mm, basally ca 0,25mm in , acicular, elliptic or circular in cross section, bulbous basally, spreading, yellowish brown to brownish or yellow, grey in age, eventually deciduous]]; hairs from lower part of areole  numerous white or brownish, mature vegetative areoles usually lacking hairs, juveline plants have spines shorter and fewer; epidermis glaucous green or bluish green, often  purplish, smooth. Flowers 17-22,5cm long, fragrant reminding or vanilla and orange-flower; pericarpel 25mm long, with bracteoles 5mm, strap-shaped and yellowish, covered with nearly white or tawny hairs and sharp bristles; receptacle 7,5-8,7cm, bracteoles 5-14mm, strap-shaped to linear, yellowish with long, nearly white or tawny, wavy hairs and sharp bristles in their axils, ca 25mm long; outer tepals 7,5-10cm long, averaging 4,5mm wide, linear-attenuate, light brown, salmon to pink buff, yellowish adaxially; inner tepals 7,5-10cm long, 9- 12(-15)mm, shorter than outer tepals, wide, lanceolate, gradually narrowed into a pointed or acute apex, white; stamens 38-50mm long, delinate, white, anthers 1,5mm long, yellowish; style 15-20cm long, often longer than inner tepals, 1,5mm greatest , stigma lobes 7-12, ca 7,5mm long, slender. Fruit ovoid, 5-9cm long, 4,5-7cm thick, whitish, partly pink, pink, yellow or orange, covered with clusters of spines and hairs which soon drop off, juicy, the imbilicus small and inconspicuous.
Four subspecies are recognized:
- ssp. donkelaarii (Salm-Dyck) Ralf Bauer
ssp. grandiflorus
ssp. hondurensis (K.Schum. ex Weing.) Ralf Bauer
ssp. lautneri Ralf Bauer
- ssp. donkelaarii (Salm-Dyck) Ralf Bauer
- ssp. grandiflorus
- ssp. hondurensis (K.Schum. ex Weing.) Ralf Bauer
- ssp. lautneri Ralf Bauer

# Hybrids
Selenicereus callianthus (Gaillard) Lindinger (1942) Beitrage zur Kenntnis dikotyler Pflanzen. BBC LXI:385
Cereus grandiflorus callianthus (Gaillard) Rumpler in Forster (1885) Handb. Cact. ed. 2. 750
Cereus callianthus Gaillard (1864) Revue horticole 357
This is a hybrid between this species and Selenicereus pteranthus. Many plants under the name Selenicereus grandiflorus belong to this cross. It is very similar to Selenicereus pteranthus, but stems more slender and spines, longer and yellowish.

# Medical use
The plant is used in homeopathy, a remedy for this species is sometimes recommended for urinary tract infections and heart conditions such as the crushing pain of angina. Although it exhibits proven effects on the heart, its value as a remedy has not been officially recognized. In folk medicine, Selenicereus grandiflorus has also been used to treat the spitting up of bloody sputum, heavy or painful menstrual periods, and hemorrhages. The juice of the plant has been used for bladder infections, shortness of breath, and water retention. Applied externally, it has been used for rheumatism. And in homeopathic medicine, it's recommended for spasmodic pain and hemorrhage. It is also assumed to be an aphrodisiac.