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 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.
The Sonoran Desert is a North American desert which covers large parts of the Southwestern United States in Arizona and California and of Northwestern Mexico in Sonora, Baja California, and Baja California Sur. It is the hottest desert in Mexico. It has an area of 260,000 square kilometers (100,000 sq mi). The western portion of the United States–Mexico border passes through the Sonoran Desert.
Barrel cacti are various members of the two genera Echinocactus and Ferocactus, found in the deserts of Southwestern North America. Some of the largest specimens can be found in the Mojave Desert in southern California.
Mammillaria is one of the largest genera in the cactus family (Cactaceae), with currently 200 known species and varieties recognized. Most of the mammillarias are native to Mexico, but some come from the southwest United States, the Caribbean, Colombia, Venezuela, Guatemala and Honduras. The common name "pincushion cactus" refers to this and the closely related genus Escobaria.
Echinopsis peruviana, the Peruvian torch cactus, is a fast-growing columnar cactus native to the western slope of the Andes in Peru, between about 2,000–3,000 m (6,600–9,800 ft) above sea level. It contains the psychoactive alkaloid mescaline as well as other alkaloids, although reported levels vary considerably and do not approach the concentrations found in Echinopsis pachanoi.
Melocactus, also known as the Turk's cap cactus, is a genus of cactus with about 30–40 species. They are native to the Caribbean, western Mexico through Central America to northern South America, with some species along the Andes down to southern Peru, and a concentration of species in northeastern Brazil.
Cylindropuntia is a genus of cacti, containing species commonly known as chollas, native to northern Mexico and the Southwestern United States. They are known for their barbed spines that tenaciously attach to skin, fur, and clothing.
Stenocereus thurberi, the organ pipe cactus or pitahaya, is a species of cactus native to Mexico and the United States. The species is found in rocky desert. Two subspecies are recognized based on their distribution and height. The Organ Pipe Cactus National Monument is named for the species.
Cactoblastis cactorum, the cactus moth, South American cactus moth or nopal moth, is native to Argentina, Paraguay, Uruguay and southern Brazil. It is one of five species in the genus Cactoblastis that inhabit South America, where many parasitoids and pathogens control the expansion of the moths' population. This species has been introduced into many areas outside its natural range, including Australia, the Caribbean, and South Africa. In some locations, it has spread uncontrollably and was consequently classified an invasive species. However, in other places such as Australia, it has gained favor for its role in the biological control of cacti from the genus Opuntia, such as prickly pear.
Ferocactus wislizeni, the fishhook barrel cactus, also called Arizona barrel cactus, candy barrel cactus, and Southwestern barrel cactus, is a species of flowering plant in the cactus family Cactaceae, native to northern Mexico and the southern United States. It is a ball-shaped cactus eventually growing to a cylindrical shape, with spiny ribs and red or yellow flowers in summer.
Echinocereus triglochidiatus is a species of hedgehog cactus known by several common names, including kingcup cactus, claretcup, and Mojave mound cactus. This cactus is native to the southwestern United States and northern Mexico, where it is a resident of varied habitats from low desert to rocky slopes, scrub, and mountain woodland. It is most abundant in shady areas.
Escobaria vivipara is a species of cactus known by several common names, including spinystar, viviparous foxtail cactus, pincushion cactus and ball cactus. It is native to North America, where certain varieties can be found from Mexico to Canada. Most of these varieties are limited to the Mojave and Sonoran Deserts. This is a small cactus growing to a maximum height of about 15 cm (6 in), often remaining smaller and oblong or spherical. It is densely covered in a mat of star-shaped arrays of straight white spines 1 to 2.5 cm long. It flowers in yellow, pink, or purple blooms 2–5 cm across.
Echinopsis pachanoi — known as San Pedro cactus — is a fast-growing columnar cactus native to the Andes Mountains at 2,000–3,000 m (6,600–9,800 ft) in altitude. It is found in Argentina, Bolivia, Chile, Ecuador and Peru, and it is cultivated in other parts of the world. Uses for it include traditional medicine and traditional veterinary medicine, and it is widely grown as an ornamental cactus. It has been used for healing and religious divination in the Andes Mountains region for over 3,000 years. It is sometimes confused with its close relative Echinopsis peruviana.
Opuntia humifusa, commonly known as the devil's-tongue, eastern prickly pear or Indian fig, is a cactus native to parts of eastern North America.
The saguaro is an arborescent (tree-like) cactus species in the monotypic genus Carnegiea, which can grow to be over 40 feet (12 m) tall. It is native to the Sonoran Desert in Arizona, the Mexican State of Sonora, and the Whipple Mountains and Imperial County areas of California. The saguaro blossom is the state wildflower of Arizona. Its scientific name is given in honor of Andrew Carnegie. In 1994, Saguaro National Park, near Tucson, Arizona, was designated to help protect this species and its habitat.
Lophophora williamsii or peyote is a small, spineless cactus with psychoactive alkaloids, particularly mescaline. Peyote is a Spanish word derived from the Nahuatl, or Aztec, peyōtl [ˈpejoːt͡ɬ], meaning "glisten" or "glistening". Other sources translate the Nahuatl word as "Divine Messenger". Peyote is native to Mexico and southwestern Texas. It is found primarily in the Chihuahuan Desert and in the states of Coahuila, Nuevo León, Tamaulipas, and San Luis Potosí among scrub. It flowers from March to May, and sometimes as late as September. The flowers are pink, with thigmotactic anthers.
Acanthocereus tetragonus is a species of cactus that is native to Florida and the Lower Rio Grande Valley of Texas in the United States, Mexico, Central America, Caribbean, and northern South America. Common names include night-blooming cereus, barbed-wire cactus, sword-pear, dildo cactus, triangle cactus, and Órgano-alado de pitaya (Spanish). It was originally described by Carl Linnaeus in 1753 as Cactus tetragonus but was moved to the genus Acanthocereus in 1938 by Pieter Wagenaar Hummelinck.
Opuntia, commonly called prickly pear, is a genus in the cactus family, Cactaceae. Prickly pears are also known as tuna (fruit), sabra, nopal from the Nahuatl word nōpalli for the pads, or nostle, from the Nahuatl word nōchtli for the fruit; or paddle cactus. The genus is named for the Ancient Greek city of Opus, where, according to Theophrastus, an edible plant grew and could be propagated by rooting its leaves. The most common culinary species is the Indian fig opuntia.
Many cacti are known to be psychoactive, containing phenethylamine alkaloids such as mescaline However, the two main ritualistic (folkloric) genera are Echinopsis, of which the most psychoactive species is the San Pedro cactus, and Lophophora, with peyote being the most psychoactive species. Several other species pertaining to other genera are also psychoactive, though not always used with a ritualistic intent.
