A cactus is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1,750 known species of the order Caryophyllales. The word cactus derives, through Latin, from the Ancient Greek word κάκτος (káktos), 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. They are native to the Americas, ranging from Patagonia in the south to parts of western Canada in the north, with the exception of Rhipsalis baccifera, which is also found in Africa and Sri Lanka. Cacti are adapted to live in very dry environments, including the Atacama Desert, one of the driest places on Earth. Because of this, cacti show many adaptations to conserve water. For example, 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 true leaves, cacti's enlarged stems carry out photosynthesis.
Acanthocereus is a genus of cacti. Its species take the form of shrubs with arching or climbing stems up to several meters in height. The generic name is derived from the Greek word άκανθα (acantha), meaning spine, and the Latin word cereus, meaning candle. The genus is native to the mostly tropical Americas from Texas and the southern tip of Florida to the northern part of South America, including islands of the Caribbean.
Cleistocactus is a genus of flowering plants in the cactus family Cactaceae, native to mountainous areas - to 3,000 m (9,843 ft) - of South America. The name comes from the Greek kleistos meaning closed because the flowers hardly open.
Bergerocactus emoryi is a species of cactus, known commonly as the golden-spined cereus, golden snake cactus, velvet cactus or golden club cactus. It is a relatively small cactus, but it can form dense thickets or colonies, with the dense yellow spines giving off a velvety appearance when backlit by the sun. From April to May, yellow, green-tinged flowers emerge, which transform into reddish, globular fruit. This species is native to the California Floristic Province, and is found in northwestern Baja California and a small part of California, in San Diego County and on the southern Channel Islands. Where the Mediterranean climate of the California Floristic Province collides with the subtropical Sonoran Desert near El Rosario, hybrids with two other species of cacti are found. It is the sole member of the monotypic genus Bergerocactus, named after German botanist Alwin Berger.
Jasminocereus is a genus of cacti with only one species, Jasminocereus thouarsii, endemic to the Galápagos Islands, territorially a part of Ecuador. In English it is often called the candelabra cactus. At maturity it has a branched, treelike habit, and may be up to 7 m (23 ft) tall. The stems are made up of individual sections with constrictions between them. Its creamy white to greenish flowers open at night and are followed by greenish to reddish fruits.
The lava cactus is a species of cactus, Brachycereus nesioticus, the sole species of the genus Brachycereus. The plant is a colonizer of lava fields – hence its common name – where it forms spiny clumps up to 60 cm (24 in) tall. Its solitary white or yellowish white flowers open in the daytime. It is endemic to the Galápagos Islands.
Discocactus is a genus of tropical cacti. Discocactus plants are endemic to southern Brazil, eastern Bolivia, and northern Paraguay. These species are in the risk of extinction in the wild.
Oroya is a genus of cacti, originating from Peru. The genus Oroya is widespread in the Peruvian Andes.
Reicheocactus, is a monotypic genus of cactus in the family Cactaceae, native to north western Argentina. It has only one known species; Reicheocactus famatimensis(Speg.) Schlumpb.
Samaipaticereus is a genus of cactus containing the sole species Samaipaticereus corroanus. It is known only from East Andean Bolivia and Peru.
Echinopsis lageniformis, synonyms including Echinopsis scopulicola and Trichocereus bridgesii, is a cactus native to Bolivia. It is known as the Bolivian torch cactus. Among the indigenous populations of Bolivia, it is sometimes called achuma or wachuma, although these names are also applied to related species such as Trichocereus macrogonus which are also used for their psychedelic effects.
Cleistocactus winteri is a succulent of the family Cactaceae. Its common name is the golden rat tail. Cleistocactus winteri subsp. colademono, as its synonym Cleistocactus colademononis, has gained the Royal Horticultural Society's Award of Garden Merit.
Lobivia mamillosa is a species of cactus from Bolivia.
Soehrensia candicans is a species of cactus from northern and western Argentina. It has large fragrant white flowers that open at night.
Denmoza is a monotypic genus of cacti. Its only species, Denmoza rhodacantha, is native to northwest Argentina.
Acanthocalycium spiniflorum is a species of flowering plant in the cactus family Cactaceae from Argentina.
Lobivia ancistrophora is a species of cactus. It has a globular shape, few spines, with large, white flowers attached to long, green tubes. It occurs in Bolivia, at altitudes of 600–1800 metres. Under its synonym Echinopsis ancistrophora it has gained the Royal Horticultural Society's Award of Garden Merit.
Acanthocalycium klinglerianum is a species of cactus endemic to Bolivia.
Pachycereus weberi is a columnar cactus plant native to Mexico.
Acanthocalycium leucanthum is a species of flowering plant in the cactus family Cactaceae from Argentina.
