Schlumbergera is a genus of cacti. The genus includes six species, originally found in south-eastern Brazil. These cacti, along with a number of cultivars are common houseplants. They are also known as Christmas Cactus or Thanksgiving Cactus. This name refers to the time of the year when the cacti flourish, in Europe. In the wild, the cacti grow on trees as epiphytes or rocks, and can form shrubss up to 1.2 metres (3.9 ft) high. The cacti do not have leaves, the green stem segments do photosynthesis. Charles Lemaire first described them in 1858. It is named after Frédéric Schlumberger a cactus collector and plant breeder.