Selenicereus atropilosus Mexico. Flowers 12 cm long, receptacle with black hairs. The species is close to some species in the genus Weberocereus
Selenicereus chrysocardium Mexico. Stems deeply lobed, ca. 28 cm wide. Flowers 32-38 cm long, 23-30 cm wide, base of receptacle very spiny. The species is close to the genus Epiphyllum.
Jamaica, Cuba; Guatemala, Honduras, Nicaragua. Stems many-ribbed. Flowers 18 cm long, receptacle densely woolly. Three subspecies are recognized:
ssp. donkelaarii - Mexico. Stems 1 cm thick, low-ribbed, spines short, appressed to stem. Flowers 18 cm long.
The following species are very closely related to each other and possibly better treated as synonymous taxa or subspecies.
Cuba, Haiti, Dominican Republic, Mexico. Flowers 24-39 cm long. Close to S. pteranthus.
Cuba. Spines less and 1 mm long. Flowers 25 cm long. A shortspined S. grandiflorus.
Mexico. Stems thick, usually with 5-6 ribs, spines to 1,5 cm long. Flowers 22-25 cm long. A long spined S. pteranthus or few ribbed S. grandiflorus.
Colombia? Only known in cultivation and possibly a hybrid with S. macdonaldiae and some other "species".
Honduras? Stem ribs tubercled. Flowers 30-34 cm long.
Cuba, Haiti, Dominican Republic. Stems 4-5-ribbed, flowers 20-30 cm long.
Selenicereus hamatus Mexico. Stems 3-4-ribbed, with knobby projections, nearly spineless. Flowers 20-25 cm long, receptacle with black hairs.
Selenicereus inermis Venezuela, Colombia. Stems 2-5-ribbed, almost spineless. Flower 15 cm long, spiny, hairless. The following species are probably best treated as synonymous or subspecies of S. inermis:
Mexico. Stems 4-5-ribbed. Flowers 18 cm. wide, 18-19 cm long, inner and outer inner tepals flushed ruby-red near base.
Costa Rica. Stem with 6-12 low ribs. Flower 15-16 cm long, spiny, hairless.
Selenicereus murrillii Mexico. Stems only 8 mm thick, nearly spineless. Flowers 15 cm long, spiny, hairless. Closely related to S. spinulous and S. inermis (sensu lat.).
Two forms are recognized.
f. macdonaldiae - Honduras? Stem ribs tubercled. Flowers 30-34 cm long.
f. pteranthus - Mexico. Stems thick, 4-5-ribbed, spines very short. Flowers 25-30 cm long.
Selenicereus spinulosus Texas, Mexico. Stems short-spined. Flowers 8?-14 cm long, receptacle spiny, hairless.
Selenicereus vagans Mexico. Flower 15 cm long, receptacle spiny, hairless.
'Selenicereus validus Michoacan, huge nocturnal flowers with bright red fruits. (Mesa Gardens 1244.5936)