Rhipsalis is a genus of epiphytic flowering plants in the cactus family, typically known as mistletoe cacti. They are found in parts of Central America, the Caribbean and northern regions of South America. They also inhabit isolated locations in Africa and Asia, and are the only cactus group naturally occurring in the Old World. This is the largest and most widely distributed genus of epiphytic cacti (those which live on other plants without damaging them). The morphology of Rhipsalis is very variable. The plants can grow mostly pendent, few grow more or less upright or sprawling. There are three main stem shapes: terete, angular and flattened. The stems are succulent, but the degree of succulence varies between the species. Some have very thick stems, whereas other have very thin, filiform stems (e.g. Rhipsalis baccifera, Rhipsalis clavata). In the majority of species, spines are missing or occur only in the juvenile stage (this is most prominent in Rhipsalis dissimilis). Rhipsalis pilocarpa has stems and fruits densely covered by bristes, making this species easily distinguishable from all other Rhipsalis. The flowers are borne lateral or apical and are actinomorphic with a varying number of perianth segments, stamens and carpels. They are small, usually about 1 cm in diameter, white or whitish in most species. Yellowish flowers occur in R. dissimilis and R. elliptica and R. hoelleri is the only Rhipsalis species with red flowers. The fruits are always berries, they are whitish or coloured pink, red or yellow. Vivipary has been observed in R. micrantha and R. baccifera.