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 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. Although some species live in quite humid environments, 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.
Nopal is a common name in Spanish for Opuntia cacti, as well as for its pads.
Night-blooming cereus is the common name referring to a large number of flowering ceroid cacti that bloom at night. The flowers are short lived, and some of these species, such as Selenicereus grandiflorus, bloom only once a year, for a single night. Other names for one or more cacti with this habit are princess of the night, Honolulu queen, Christ in the manger, dama de noche and queen of the night.
Opuntia ficus-indica, the Indian fig opuntia, fig opuntia, or prickly pear, is a species of cactus that has long been a domesticated crop plant grown in agricultural economies throughout arid and semiarid parts of the world. O. ficus-indica is the most widespread and most commercially important cactus. It is grown primarily as a fruit crop, and also for the vegetable nopales and other uses. Cacti are good crops for dry areas because they convert water into biomass efficiently. O. ficus-indica, as the most widespread of the long-domesticated cactuses, is as economically important as maize and blue agave in Mexico. Because Opuntia species hybridize easily, the wild origin of O. ficus-indica is likely to have been in Mexico because its close genetic relatives are found in central Mexico.
The term ceroid cactus is used to describe any of the species of cacti with very elongated bodies, including columnar growth cacti and epiphytic cacti. The name is from the Latin cēreus, wax taper, referring to the stiff, upright form of the columnar species. Some species of ceroid cacti were known as torch cactus or torch-thistle, supposedly due to their use as torches by Native Americans in the past.
The Cactoideae are the largest subfamily of the cactus family, Cactaceae. Around 80% of cactus species belong to this subfamily. As of August 2018, the internal classification of the family Cactaceae remained uncertain and subject to change. A classification incorporating many of the insights from the molecular studies was produced by Nyffeler and Eggli in 2010. Various revisions have been published since, e.g. to the tribe Hylocereeae and the tribe Echinocereeae. Classifications remained uncertain as of March 2019.
The strawberry hedgehog cactus or Engelmann's hedgehog cactus is commonly found in desert areas of the southwestern United States and the adjacent areas of Mexico, including the states of California, Nevada, Utah, Arizona, Baja California and Sonora.
Opuntia engelmannii is a prickly pear common across the south-central and Southwestern United States and northern Mexico. It goes by a variety of common names, including desert prickly pear, discus prickly pear, Engelmann's prickly pear in the US, and nopal, abrojo, joconostle, and vela de coyote in Mexico.
Opuntia stricta is a large-sized species of cactus that is endemic to the subtropical and tropical coastal areas of the Americas, especially around the Caribbean. Common names include erect prickly pear and nopal estricto (Spanish). The first description as Cactus strictus was published in 1803 by Adrian Hardy Haworth. In 1812 he introduced the species in the genus Opuntia.
Opuntia phaeacantha is a species of prickly pear cactus known by the common names tulip prickly pear, Mojave prickly pear, and desert prickly pear found across the southwestern United States, lower Great Plains, and northern Mexico. The plant forms dense but localized thickets. Several varieties of this particular species occur, and it also hybridizes easily with other prickly pears, making identification sometimes tricky.
A pitaya or pitahaya is the fruit of several different cactus species indigenous to the Americas. Pitaya usually refers to fruit of the genus Stenocereus, while pitahaya or dragon fruit refers to fruit of the genus Selenicereus, both in the family Cactaceae. Dragon fruit is cultivated in Mexico, Southeast Asia, East Asia, India, the United States, the Caribbean, Australia, Mesoamerica and throughout tropical and subtropical regions of the world.
Opuntia humifusa, commonly known as the devil's-tongue, Eastern prickly pear or Indian fig, is a cactus of the genus Opuntia present in parts of eastern North America.
Opuntia, commonly called prickly pear or pear cactus, is a genus of flowering plants 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.
Opuntia littoralis is a species of prickly pear cactus known by the common name coastal pricklypear. It is sometimes called the sprawling prickly pear due to its short stems and habit of growing close to the ground. "Littoral" means "pertaining to the seashore".
Prickly pears include a number of plant species that were introduced and have become invasive in Australia.
Stenocereus griseus, also known as the Mexican organ pipe, dagger cactus, pitaya, and pitayo de mayo, is a species of cactus.
Opuntia aciculata, also called Chenille pricklypear, old man's whiskers, and cowboy's red whiskers, is a perennial dicot and an attractive ornamental cactus native to Texas. It belongs to the genus Opuntia. It is also widespread in Nuevo Leon, Tamaulipas.
Opuntia macrocentra, the long-spined purplish prickly pear or purple pricklypear, is a cactus found in the lower Southwestern United States and Northwestern Mexico. A member of the prickly pear genus, this species of Opuntia is most notable as one of a few cacti that produce a purple pigmentation in the stem. Other common names for this plant include black-spined pricklypear, long-spine prickly pear, purple pricklypear, and redeye prickly pear.
Flora of the Sonoran Desert includes six subdivisions based on vegetation types. Two are north of the boundary between the United States and Mexico, and four are south of the boundary. The flora of the Colorado Desert are influenced by the environment of the very dry and hot lower areas of the Colorado River valley, which may be barren, treeless, and generally have no large cacti. Flora of the Arizona Upland are comparatively lush, with trees and large columnar cacti that can withstand winter frosts. South of the border subdivisions are characterized by plants that cannot withstand frost.
Opuntia rufida is a species of prickly pear cactus native to southwestern Texas and northern Mexico, where it grows on rocky slopes. The species makes up for its total lack of spines with a profusion of red-brown glochids. The common name blind prickly pear or cow blinder comes from the fact that the glochids may be carried away by the wind and blind animals.
