A cactus is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word "cactus" derives, through Latin, from the Ancient Greek κάκτος, kaktos, a name originally used by Theophrastus for a spiny plant whose identity is now not certain. Cacti occur in a wide range of shapes and sizes. Most cacti live in habitats subject to at least some drought. Many live in extremely dry environments, even being found in the Atacama Desert, one of the driest places on earth. Cacti show many adaptations to conserve water. Almost all cacti are succulents, meaning they have thickened, fleshy parts adapted to store water. Unlike many other succulents, the stem is the only part of most cacti where this vital process takes place. Most species of cacti have lost true leaves, retaining only spines, which are highly modified leaves. As well as defending against herbivores, spines help prevent water loss by reducing air flow close to the cactus and providing some shade. In the absence of leaves, enlarged stems carry out photosynthesis. Cacti are native to the Americas, ranging from Patagonia in the south to parts of western Canada in the north—except for Rhipsalis baccifera, which also grows in Africa and Sri Lanka.
Schlumbergera truncata, the false Christmas cactus, is a species of plant in the family Cactaceae. It is endemic to a small area of the coastal mountains of south-eastern Brazil where its natural habitats are subtropical or tropical moist forests. It is the parent or one of the parents of the houseplants called Christmas cactus or Thanksgiving cactus, among other names.
Schlumbergera is a small genus of cacti with six to nine species found in the coastal mountains of south-eastern Brazil. These plants grow on trees or rocks in habitats that 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. Two species have cylindrical stems more similar to other cacti. Recent phylogenetic studies using DNA have led to three species of the related genus Hatiora being transferred into Schlumbergera, though this change is not universally accepted.
Epiphyllum is a genus of epiphytic plants in the cactus family (Cactaceae), native to Central America. Common names for these species include climbing cacti, orchid cacti and leaf cacti, though the latter also refers to the genus Pereskia.
Hatiora is a small genus of epiphytic cacti which belongs to the tribe Rhipsalideae within the subfamily Cactoideae of the Cactaceae. Recent taxonomic studies have led to the three species formerly placed in subgenus Rhipsalidopsis being removed from the genus, including the well known and widely cultivated ornamental plants known as Easter cactus or Whitsun cactus.
Disocactus crenatus, the crenate orchid cactus, is a species of cactus and one of the most important parents in creating the epiphyllum hybrids commonly cultivated throughout the world. It is cultivated for its large white flowers.
Epiphyllum oxypetalum is a species of cactus and one of the most cultivated species in its genus. E. oxypetalum rarely blooms and only at night, and its flowers wilt before dawn. Though it is sometimes referred to as a night-blooming cereus, it is not closely related to any of the species in the tribe Cereeae, such as Selenicereus, that are more commonly known as nightblooming cereus. All Cereus species bloom at night and are terrestrial plants; Epiphyllum species are usually epiphytic.
Aporocactus flagelliformis, the rattail cactus, is a species of flowering plant in the cactus family Cactaceae, and is the most cultivated species in the genus Aporocactus. Due to its ease of cultivation and attractive floral displays, it is often grown as an ornamental potted plant.
Disocactus phyllanthoides, the nopalxochitl or German empress, is a species of flowering plant in the cactus family Cactaceae. It is commonly grown as an ornamental houseplant. It is one of the three major species involved in creating the widely grown epiphyllum hybrids or "epis". The others are Disocactus speciosus and Epiphyllum crenatum.
Disocactus anguliger, commonly known as the fishbone cactus or zig zag cactus, is a cactus species native to Mexico. The species is commonly grown as an ornamental for its fragrant flowers in the fall.
Epiphyllum laui is a cactus species native to Mexico and grown as an ornamental.
Selenicereus megalanthus, synonym Hylocereus megalanthus, is a cactus species in the genus Selenicereus that is native to northern South America, where it is known, along with its fruit, by the name of pitahaya. The species is grown commercially for its yellow fruit, but is also an impressive ornamental climbing vine with perhaps the largest flowers of all cacti.
Schlumbergera kautskyi is a species of plant in the family Cactaceae. It is endemic to a small area of the coastal mountains of south-eastern Brazil where its natural habitat is rocky areas. It is threatened by habitat loss. It is in the same genus as the popular houseplant known as Christmas cactus or Thanksgiving cactus.
Schlumbergera microsphaerica is a species of plant in the family Cactaceae. It is endemic to a limited area of the coastal mountains of south-eastern Brazil where its natural habitat is rocky areas above 2,600 m (8,500 ft). It is threatened by habitat loss. It is in the same genus as the popular house plant known as Christmas cactus or Thanksgiving cactus.
Schlumbergera opuntioides is a species of plant in the family Cactaceae. It is endemic to the coastal mountains of south-eastern Brazil where its natural habitats are humid forests and rocky areas. It is threatened by habitat loss. It is in the same genus as the popular house plant known as Christmas Cactus or Thanksgiving Cactus.
Selenicereus grandiflorus is a cactus species originating from the Antilles, Mexico and Central America. The species is commonly referred to as queen of the night, night-blooming cereus, large-flowered cactus, sweet-scented cactus or vanilla cactus. The true species is extremely rare in cultivation. Most of the plants under this name belong to other species or hybrids. It is often confused with the genus Epiphyllum.
Schlumbergera orssichiana is a species of plant in the family Cactaceae. It is endemic to a small area of the coastal mountains of south-eastern Brazil where its natural habitat is moist forest. It grows on trees as an epiphyte. It is in the same genus as the popular houseplant known as Christmas cactus or Thanksgiving cactus.
The Rhipsalideae are a small tribe of cacti, comprising four genera. They grow on trees (epiphytes) or on rocks (lithophytes), where they either hang down or form creeping or upright shrubs. Their flowers open in the day and remain open at night; they may be either radially symmetrical (regular) or bilaterally symmetrical (zygomorphic). The fruits are berry-like, fleshy with smallish seeds.
Schlumbergera gaertneri, formerly Hatiora gaertneri, is a species of epiphytic cactus which belongs to the tribe Rhipsalideae within the subfamily Cactoideae of the Cactaceae. Together with the hybrid with S. rosea, Schlumbergera × graeseri, it is known as Easter cactus or Whitsun cactus and is a widely cultivated ornamental plant. It has received the Royal Horticultural Society's Award of Garden Merit.
Schlumbergera lutea, synonym Hatiora epiphylloides, is a species of flowering plant in the family Cactaceae, subfamily Cactoideae, native to southeast Brazil. It is a shrubby epiphyte, with flattened stems and bright yellow flowers.
