Schlumbergera aka Madame Butterfly Variegated Christmas Cactus

Schlumbergera is a small genus of leafless cacti, with six to nine species native to the coastal mountains of southeastern Brazil. These plants can be found growing on trees or rocks in shady, humid habitats, and are quite different in appearance from their desert-dwelling cousins. The stems of most Schlumbergera species resemble leaf-like pads joined together, with flowers that appear from areoles at the joints and tips of the stems. However, two species have cylindrical stems more similar to other cacti. These cacti are commonly known as Christmas cactus, Thanksgiving cactus, crab cactus, and holiday cactus in the Northern Hemisphere, while in Brazil, they are referred to as Flor de Maio (May flower) due to their flowering period in the Southern Hemisphere. Most of the popular houseplants are cultivars of Schlumbergera, rather than species, with flowers in various colors such as white, pink, yellow, orange, red, or purple. The Easter cactus or Whitsun cactus, which has flowers in red, orange, pink, and white, is placed in the genus Rhipsalidopsis but is also called a holiday cactus. The species of Schlumbergera grow either epiphytically on trees or epilithically on rocks and can form sizeable shrubs with woody bases. They are composed of segments, which take one of two forms. In most species, the segments are strongly flattened (cladodes), being made up of a central core with two (or more rarely three) "wings". In two species, the stems are less flattened, more cylinder-shaped, and the areoles are arranged in a more or less spiral pattern all over the segments. The flowers either hang downwards and are almost regular (radially symmetrical or actinomorphic) or, as in most species, are held more or less horizontally with the higher side of the flower different from the lower side (radially asymmetrical or zygomorphic). The cultivars of the Christmas cactus fall into two main groups: the Truncata Group and the Buckleyi Group. The Truncata Group contains all cultivars with features mainly derived from the species S. truncata, while the Buckleyi Group contains all cultivars with at least some features showing inheritance from S. russelliana. The Truncata Group generally flowers earlier and may be distinguished as Thanksgiving cactus, crab cactus, or claw cactus, while the Buckleyi Group generally flowers later and is more likely to be called Christmas cactus. Each flower of Schlumbergera has 20-30 tepals, with the outer tepals being short and unconnected, and the inner tepals becoming progressively more fused together at the base to form a floral tube. The flowers produce nectar in a chamber at the base of the floral tube. In most species, the many stamens are arranged in two series, with the inner stamens being fused at the base to form a short tubular structure and the outer stamens arising from along the floral tube. The style is usually dark red and has a stigma with 6-8 lobes, roughly the same length as the stamens. If the flower is fertilized, a fleshy fruit forms, either smooth or with ribs, with brown or black seeds about 1 mm in diameter.