The Christmas cacti are common flowering pot plants grown primarily for autumn and winter sales. There has been much confusion over the naming of these plants. The true Christmas cactus, Schlumbergera x buckleyi is a hybrid between S. truncata (the Thanksgiving cactus) and S. russelliana. Previously it was called S. bridgesii. The true Christmas cactus characteristically has scalloped-edged stem-segments(phylloclades), while those of the Thanksgiving cactus are toothed. The latter has been previously known as Epiphyllum truncatum and Zygocactus truncatus. Much hybridisation has taken place with these plants and many cultivars are derived from crosses between Christmas and Thanksgiving cacti. Collectively they are commonly known as Christmas cacti, holiday cacti, schlumbergeras, and zygocactus and their cultural requirements are similar.