Schlumbergera is a small genus of cacti with six species found in the coastal mountains of south-eastern Brazil.Plants grow on trees or rocks in habitats which are generally shady with high humidity and can be quite different in appearance from their desert-dwelling cousins. Most species of Schlumbergera have stems which resemble leaf-like pads joined one to the other and flowers which appear from areoles at the joints and tips of the stems.
This genus contains the popular house plants known by a variety of names including Christmas Cactus, Thanksgiving Cactus, Crab Cactus and Holiday Cactus, which are Schlumbergera cultivars, and flower in white, pink, yellow, orange, red or purple. Schlumbergera species grow in habitats which are generally relatively cool, shaded and of high humidity. The flowers of Schlumbergera have adaptations for pollination by hummingbirds: tubular flowers with abundant nectar, and colours towards the red end of the spectrum. Most species require cross-pollination to set seed.