The genus includes more than 20 species. Theirare probably the finest and the largest of all Cactaceae. They are nocturnal, or mostly so, strongly perfumed, and open towards sunset but wither off at sunrise. They are popularly named “Queen of the Night”. Those who have seen these flowers in the fading light are struck by their unearthly radiance.
Selenicereus grandiflorus. West Indies. Often described as a marvel of the vegetable kingdom. The flowers have inspired both painters and poets of many countries. It is a climbing species with fairly thin snake-like branches, green to greyish-green in colour, with 8 ribs. The spines are short, yellow or brownish with white hairs. Cuttings are easily propagated and grow quickly when rooted. The plants require frequentthroughout the summer. They should be grown in a consisting of 1 part -mould, 1 part loam, and 1 part sand, to which has been added a small quantity of old mortar rubble.
Selenicereus Macdonaldiae. Uruguay and Argentina. A species frequently seen in cultivation, quick growing and much branched. Theare dark shiny green, sometimes shaded dark purple, with 5 to 7 ribs. There are few spines. The flowers, which appear in June and July, are large and white, but have no fragrance.
Selenicereus pteranthus. Mexico. A magnificent species. The stiff stems have 4 to 5 angles, and are a dull glaucous green, flushed with purple. The areoles have short, white wool and very short, thick and stiff spines. Flowers creamy-white with long narrow sepals, purplish-yellow on the outside, expanding horizontally. A free-flowering species.