These can be described as forest climbing. They have long snake-like branches studded with beautiful blossoms with red, purplish or greenish sepals, and with white petals. There are about 18 species. They prefer half shade and warmth and in summer-time liberal . The are nocturnal.
Hylocereus undatus. West Indies. Famous for its very large blooms, it is commonly met with in cultivation. Theare deep green, much branched and triangular; the spines very short and thick. Frequently used as grafting stock for Zygocactus, Epi-phyllum, and Rhipsalis. Of easy cultivation in a mixture of 1 part loam, 1 part -mould, and 1 part sand.