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About Cacti

What is a Cactus?


Evolution and Phylogeny


Illustrative Genera

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Economics of Cacti

As Food for Humans
As Food for Livestock
Production of Cochineal Dye
As Hallucinogens

(Adapted from Nobel, 1985)


Interest in cacti is as diverse as the growth forms of the plants themselves. Throughout the world cacti are extensively used in horticulture. Where cacti can be grown out-of-doors, they are planted in gardens as ornamentals and are often used as hedges - the spiny cacti make effective boundary markers.

In temperate regions, the cultivation of cacti is a growing hobby and to date perhaps no other plant family has as many representations in homes worldwide as does the Cactaceae. About 300 species of cacti are available as ornamentals. The ubiquitous attraction to cacti can be largely attributed to their unique patterns and shapes, the often bright showy flowers, and to their slow growing nature which results in infrequent need for repotting, and for watering.

Of special interest are the Jungle-, the Orchid-, the Christmas-, and the Thanksgiving cacti. These are very popular because of their special attractions at certain seasons or for their especially beautiful, very large blooms. Hundreds of thousands of "Ch ristmas" (actually S. truncatahybrids) cacti are sold each holiday season. The true Christmas Cactus (Schlumbergera x buckleyi), a hybrid clone dating to 1840, is still passed on within families as heir-looms, and very large, very old specim ens are common. The Orchid cacti, a few species (and hundreds of hybrid) Epiphyllums, are large plants which produce very large, splendid blooms as their popular name correctly implies. Easter and Mistletoe cacti are also "Jungle cacti"; interesting but n ot so widespread.

with cacti
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As Food for Humans

Cacti in general and the fruits in particular are considered staple foods for some poorer residents of Latin America, including Mexico, and in many South European and Mediterranian countries. For as much as two months of the year, they can be the main article of edible food. The fruits are appetizing and are often eaten raw. Cactus fruit is high in vitamin C, low in fat, and high in sugars, where about 1/3 of the sugar content is fructose. A "Cactus Cookbook" is available.

Throughout Latin America, local cottage industries have developed to sell fruits collected wild from more than 40 species of cacti in 15 genera. In Mexico and the United States, the cacti most commonly used for food are the prickly pear species of Opuntia, some columnar species of Cereus and the barrel cacti, Ferocactus and Echinocactus.

The fruits or tunas of prickly pears are commonly sold in the markets of Mexico and in parts of the United States along the US-Mexico border as well as in South European and in Mediterranian countries. The hybridization of prickly pear is common and new strains or cultivars arise frequently, producing tunas in many sizes, colors and flavors. Now very often available in grocery stores througout Canada, these "Tunas" have been popular and sometimes important in most Mediterranean and other countries where Opuntias have been natural ized and are cultivated on farms and plantations.

The glochids of prickly pears, minute, barbed spines, must be brushed off first before eating, either by rolling the fruits on the ground or in a bag woven from Agave fibre, swatting the fruits with large leaves and branches, wiping the fruit with a moist towel or commercially by using mechanical brushes.

Opuntia fruits

The tunas are eaten as fresh fruit, dried fruit or used for prepared foods where special varieties can be made into pickles, jams, candy, stews to make the popular taffy miel de tunaand fermented drinks such as Colonche wine and brandy. In extreme cases, seeds of some genera, e.g., Myrtillocactus, have been used as a food source, even when collected as a second harvest from human feces. The recovered, washed seeds are first roasted then eaten, or dried in the sun and ground into a flour-like meal to be used for cooking.

The fruits from the columnar cacti and barrel, "candy" cacti are also collected for human consumption although they are less well known than the fruits of the prickly pear cacti. These fruits are mainly eaten raw but can also be prepared to make the equivalents of the prickly pear miel de tuna, Colonche and wine.

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As Food for Livestock and Other Native Animals

Cactus plants provide water and some nutritional value and are an important source of food for livestock and native animals. Various species of cacti can be used as fodder. Fodder refers to the coarse plant material that is cut up and fed to the livestock. The large barrel cacti of the genus Ferocactuscan be used as fodder by simply cutting open the stem and exposing the pulp. The stems of most columnar cacti are generally chopped up to reveal the pulp.

Harvesting naturally occurring cacti can be ecologically damaging, especially when such cacti tend to propagate infrequently and are very slow growing. However, the most commonly harvested cacti used for fodder are the cultivated platyopuntias. Ranchers in the United States have long known how to make use of some species of prickly pear as fodder. However more recently many ranchers have planted platyopuntias on a limited basis, mainly as a water source for their cattle during periods of drought.

Opuntiascan also be the principal diet of the white-tailed deer. Quail, wild turkey, various rodents. Some turtles and tortoises also depend on the cacti as a food source. For desert animals such as pack rats, gophers and rabbits, the barrel cacti can be a principal source of water.

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For the Production of the Cochineal Dye

In pre-Columbian times, the culture of the cactus-eating cochineal insect was of great value to the Aztecs who used it for the manufacture of the royal red robes of Aztec emperors. Only the cochineal insect contained the vivid red dye needed to create this color, and emperors demanded that all subjects pay all tax in insects --specifically in funds of the cochineal insect.

In the sixteenth century the Spanish conquerors, impressed by the colorful Aztec robes, shipped the platyopuntias, to the Mediterranean and then to the Canary Islands for raising the cochineal insect. The Spanish traders who introduced the dye to Europe kept the secret source of the dye closely guarded, which, at one point, raised the monetary worth of the dye to more than its weight in gold. However, with the advent of twentieth-century synthetic clothing the cheap synthetic aniline dyes developed from coal tar revolutionized the dyeing industry, causing the use of cochineal to decline.

Today the dye mainly provides the carmine stain used in preparing microscope slides and is still very expensive. The carminic acid from the cochineal insect is also used as a pH indicator, and as a natural coloring in foods, soft drinks and cosmetics.

Cochineal insects feed on various species of platyopuntias. To produce the dye, cacti and the cochineal insect are cultivated and cultured on specialized plantations. Unlike the male, which develop into winged adults, the female insect furnishes the dye and is black-purple, larger than the male, and stationary. The females remain in a prolonged larval stage and draw nutrients from the cladodes of certain prickly pears via their tubular mouthparts for up to 3 years.

Today, to avoid the problems associated with rainfall and high winds the insect is incubated on detached cladodes that are subsequently maintained in sheds. The insects are removed by jets of air or are harvested by hand before extracting the dye. Once harvested the insects are often dried in the sun and then ground to produce the commonly marketed purplish powder. The insects can also be boiled in hot water to dissolve the wax coat before they are dried or boiled in water to extract the dye to be marketed in a liquid form.

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As Hallucinogens

Long before the discovery of the Americas, the Aztecs and other Indian races used the peyote plant (Lophophora williamsii) in religious rituals primarily because of its hallucinogenic properties.

The peyote is essentially a spineless plant about 8 cm in diameter that grows in Northern Mexico and Southern Texas. Only the top of its hemispherical stem is above the ground. It is cut into sections to make "buttons" which when ingested can lead to a state of mental elation. The hallucinogen is the alkaloid mescaline, a substance that produces effects similar to those produced by LSD. It leads to mild excitement of the sympathetic nervous system, resulting in dilation of the pupils, and an increase of systolic blood pressure and brain waves that can exhibit an 'arousal' pattern. Noticeable side effects can include intense nausea and hallucinogenic visions followed by a prolonged period of insomnia.

During the 19th century the Mescalero Apache and Tonkawa Indians introduced peyote ceremonies into the United States from Mexico. Peyotism subsequently radiated rapidly throughout the plains states. By the 20th century, peyotism had been introduced to most Indian tribes of the United States and Southern Canada. Today it involves about a quarter of a million believers, making peyotism the most widespread religious belief among Indians.

The widespread use of peyote in the United States stimulated both white religious leaders and the U.S. Bureau of Indian Affairs to try to discourage its use. A regulation prohibiting its ceremonial use has not yet been passed by the Federal Government, however all dealings in and consumption of mescaline, with exception to the legalized 'Native American Church' in USA and in Canada, are subject to severe penalties. In many states of the U.S. it is even illegal to cultivate Lophophora in cactus collections.

Other cacti besides Lophophora contain hallucinogens as well. For example the stems of Opuntia cylindrica can contain 0.9% mescaline by dry weight and the fruits of Opuntia leptocaulus can also be slightly hallucinogenic. Alkaloids similar to those in Peyote can also be found in some stems of saguaro. The San Pedro cactus Trichocereus pachanoi, in Ecuador and Peru is commonly used for medicinal and hallucinogenic purposes and can be purchased in the local street markets.


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Medicinal Uses

Various cactus extracts have a wide range of medical applications. Of particular importance today are the juices, extracted from crushed young stems of Opuntia, that are used as anti-diabetic agents in many parts of the world. Opuntiastems are ingested, broiled, blended or as juice and have been used in Australia, South America and many Latin American countries as a diuretic. Many platyopuntias contain mucilage, a complex polysaccharide composed of many uncommon sugars that acts as a laxative. Burns and skin sores are commonly treated with the cut stems of many species of cacti and stomach ulcers and kidney disease are often treated with various stem extracts. Many species of columnar cacti also contain steroids that can act as hormones for humans and other animals.

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