Rhipsalis quellebambensis

Rhipsalis quellebambensis is a member of the family Cactaceae and was first discovered by J. Mill Stearn in 1771. It is commonly called the mistletoe cactus and is often considered to be a synonym of "Rhipsalis baccifera".
Epiphytic nature.
This species is an epiphyte and is found high in the canopy in areas with full sun in Central America’s rain forest. "Rhipsalis quellebambensis" favors deciduous trees over evergreen trees because of the better nutrient content of the soil produced at the nodes of branches on the trees. Deciduous trees though absorb less water in their bark as compared to evergreen trees which creates more water stress on the plant. "R. quellebambensis" has 36 other species in its genus and 1800 family members that can be found on almost every continent in environments that range from hot deserts, cold deserts, dry deciduous forests, and tropical rain forests. In the Americas, the family Cactaceae ranges from Alberta, Canada to the Andes in South America. Members of the genus "Rhipsalis" are more restricted and found only in the tropical regions of Central and South America. The closest relatives of "R. quellebambensis" are found in Brazil, East Africa, and the island of Madagascar. Only 10% of the related Cactaceae species are epiphytes, making "R. quellebambensis" an unusual member of the family. In tropical rain forest though, epiphytes dominate the amount of Cactaceae species in a given area because it is the driest environment in the rain forest and where they have a competitive advantage.
Family characteristics.
The appearance of "Rhipsalis quellebambensis" is consistent with that of a cactus in many ways. Like most members of the family Cactaceae, the leaves and shoots are succulent and able to store water and sugars. The stems are highly segmented, terete, and can grow up to 2 meters in length. Anywhere that a node comes into contact with any kind of substrate, bark or soil, roots emerge from that node. The internodes in "R. quellebambensis" are larger than that in most desert Cactaceae members. The stem segments are flattened and are the site of photosynthesis within the plant. "R. quellebambensis" stems branch by forking at a node into two or more shoots. "R. quellebambensis" produces many light pink to white flowers that stay open for a long time at the end of each shoot, but only opens a small number of new flowers each night that contain a nectar reward for pollinators. "Rhipsalis quellebambensis" can be pollinated by hummingbirds that can also give the plants mites that damage the plant. This results in only a few flowers having nectar and ready for pollination each night. If pollinated, a fleshy red fruit then develops that houses multiple small black seeds. In order for the seeds to germinate though, the fruit must become overly ripe and can not be ingested by an animal. In captivity, the most common form of propagation is through stem cuttings. R. quellebambensis is also a CAM plant. This method of photosynthesis allows this species to cope with the dry environment it endures in the canopy by making it more water efficient. Studies have shown that water loss for "R. quellebambensis" is dramatically less than water loss by C3 plants such as ferns. "R. quellebambensis" can also store significant amounts of water during wet times in its bulb and stem and save it for later use. This allows the species to survive in full sun areas that are more productive where other species of epiphytes would dry out.
Distinguishing characteristics.
Unlike in most members of the family Cactaceae, "R. quellebambensis" stems grow out of a fleshy bulb. The bulb is a drought adaptation that functions to store water and carbohydrates for the plant. "R. quellebambensis" is also able to grow on very little soil. Most Cactaceae require soil as a rooting medium to provide structural support and to provide essential nutrients to the plant. The soil demands for "R. quellebambensis" are less in that the plant only requires soil for nutrients. "Rhipsalis quellebambensis" also flowers for a very long period of time when compared to other Cactaceae. The reason for this is that "Rhipsalis quellebambensis" lives in moist areas where it is able to bloom for a long period of time because it has more access to water. Even though water supplies are sporadic, the plant is able to store water long enough to allow for prolonged flowering. Water loss is kept to a minimum however because only a few flowers at a time produce nectar while others serve to attract pollinators.
Uses.
This plant does not have any significant industrial, medicinal or recreational human use but is grown by some as an ornamental in greenhouses and in people’s homes. When cultivated, this plant needs constant attention and care. Because it is an epiphyte and prone to drought because of its exposed roots, "R. quellebambensis" needs regular watering to avoid desiccation. It also needs access to full sun and be kept in a relatively warm and moist environment. "R. quellebambensis" must be either suspended in some sort of pot or grown on a tree. The plant requires regular inputs of nutrients into the soil medium for growth. This can be in the natural form of leaves and other plant debris or through the application of a fertilizer.