Prickly pears
Opuntia
Summary 5
Opuntia is a genus in the cactus family, Cactaceae.
Description 6
O. ficus-indica is a large, trunk-forming, segmented cactus that may grow to 5–7 m (16–23 ft) with a crown of over 3 m (10 ft) in diameter and a trunk diameter of 1 m (1 yd). Cladodes (large pads) are green to blue-green, bearing few spines up to 2.5 cm (1 in) or may be spineless. Prickly pears typically grow with flat, rounded cladodes (also called platyclades) containing large, smooth, fixed spines and small, hairlike prickles called glochids that readily adhere to skin or hair, then detach from the plant. The flowers are typically large, axillary, solitary, bisexual, and epiperigynous, with a perianth consisting of distinct, spirally arranged tepals and a hypanthium. The stamens are numerous and in spiral or whorled clusters, and the gynoecium has numerous inferior ovaries per carpel. Placentation is parietal, and the fruit is a berry with arillate seeds. Prickly pear species can vary greatly in habit; most are shrubs, but some, such as Opuntia echios of the Galápagos, are trees.
O. ficus-indica thrives in regions with mild winters having a prolonged dry spell followed by hot summers with occasional rain and relatively low humidity. A mean annual rainfall of 350–500 mm (14–19 1⁄2 in) provides good growth rates. O. ficus-indica proliferates in various soils ranging from subacid to subalkaline, with clay content not exceeding 15–20% and the soil well-drained. The shallow root system enables the plant to grow in shallow, loose soils, such as on mountain slopes. Opuntia spreads into large clonal colonies, which contribute to its being considered a noxious weed in some places.
Animals that eat Opuntia include the prickly pear island snail and Cyclura rock iguanas. The fruit are relished by many arid-land animals, chiefly birds, which thus help distribute the seeds. Opuntiapathogens include the sac fungusColletotrichum coccodes and Sammons' Opuntia virus. The antCrematogaster opuntiae and the spiderTheridion opuntia are named because of their association with prickly pear cactus.
Distribution 6
Like most true cactus species, prickly pears are native only to the Americas. Through human actions, they have since been introduced to many other areas of the world. Prickly pear species are found in abundance in Mexico, especially in the central and western regions, and in the Caribbean islands (West Indies). In the United States, prickly pears are native to many areas of the arid, semiarid, and drought-prone Western and South Central United States, including the lower elevations of the Rocky Mountains and southern Great Plains, where species such as Opuntia phaeacantha and Opuntia polyacantha become dominant, and to the desert Southwest, where several types are endemic. Prickly pear cactus is also native to sandy coastal beach scrub environments of the East Coast from Florida to southern Connecticut, where Opuntia humifusa, Opuntia stricta, and Opuntia pusilla, are found from the East Coast south into the Caribbean and the Bahamas. Additionally, the eastern prickly pear is native to the midwestern "sand prairies" nearby major river systems, such as the Mississippi, Illinois, and Ohio rivers. The plant also occurs naturally in hilly areas of southern Illinois, and sandy or rocky areas of northern Illinois.
Opuntia species are the most cold-tolerant of the lowland cacti, extending into western and southern Canada; one subspecies, O. fragilis var. fragilis, has been found growing along the Beatton River in central British Columbia, southwest of Cecil Lake at 56° 17’ N latitude and 120° 39’ W longitude.
Prickly pears also produce a fruit, commonly eaten in Mexico and in the Mediterranean region, known as tuna; it also is used to make aguas frescas. The fruit can be red, wine-red, green, or yellow-orange. In the Galápagos Islands, six different species are found: O. echios, O. galapageia, O. helleri, O. insularis, O. saxicola, and O. megasperma. These species are divided into 14 different varieties; most of these are confined to one or a few islands, so they have been described as "an excellent example of adaptive radiation". On the whole, islands with tall, trunked varieties have giant tortoises, and islands lacking tortoises have low or prostrate forms of Opuntia. Prickly pears are a prime source of food for the common giant tortoises in the Galápagos Islands, so they are important in the food web.
Charles Darwin was the first to note that these cacti have thigmotacticanthers; when the anthers are touched, they curl over, depositing their pollen. This movement can be seen by gently poking the anthers of an open Opuntiaflower. The same trait has evolved convergently in other species (e.g. Lophophora).
The first introduction of prickly pears into Australia is ascribed to Governor Phillip and the earliest colonists in 1788. Brought from Brazil to Sydney, prickly pear grew in Sydney, New South Wales, where they were rediscovered in a farmer's garden in 1839. They appear to have spread from New South Wales and caused great ecological damage in the eastern states. They are also found in the Mediterranean region of Northern Africa, especially in Algeria, Morocco and Tunisia, where they grow all over the countryside, and in parts of Southern Europe, especially Spain, where they grow in the east, south-east, and south of the country, and also in Malta, where they grow all over the islands. They can be found in enormous numbers in parts of South Africa, where they were introduced from South America.
Prickly pears are considered an invasive species in Australia, Ethiopia, South Africa, and Hawaii, among other locations.
Prickly pears (mostly Opuntia stricta) were originally imported into Europe during the 1500s and Australia in the 18th century for gardens, and were later used as a natural agricultural fencing and in an attempt to establish a cochineal dye industry. In Australia, they quickly became a widespread invasive weed, eventually converting 260,000 km2 (101,000 sq mi) of farming land into an impenetrable green jungle of prickly pear, in places 6 m (20 ft) high. Scores of farmers were driven off their land by what they called the "green hell"; their abandoned homes were crushed under the cactus growth, which advanced at a rate of 400,000 hectares (1,000,000 acres) per year. In 1919, the Australian federal government established the Commonwealth Prickly Pear Board to coordinate efforts with state governments to eradicate the weed. Early attempts at mechanical removal and poisonous chemicals failed, so in a last resort, biological control was attempted. The mothCactoblastis cactorum, from South America, whose larvae eat prickly pear, was introduced in 1925 and rapidly reduced the cactus population. The son of the noted entomologist Frederick Parkhurst Dodd, Alan Dodd, was a leading official in combating the prickly pear menace. A memorial hall in Chinchilla, Queensland, commemorates the moth. The release of cochineal insects that eat the cactus and simultaneously kill the plant has proven an effective measure for combatting the spread.
Natural distribution occurs via consumption and seed dispersal by many animals, including antelopes, nonhuman primates, elephants, birds, and humans. When ingested by elephants, the sharp components of the plant cause harm to the mouth, stomach, and intestines.
Regional food uses 6
The fruit of prickly pears, commonly called cactus fruit, cactus fig, Indian fig, nopales or tuna in Spanish, is edible, although it must be peeled carefully to remove the small spines on the outer skin before consumption. If the outer layer is not properly removed, glochids can be ingested, causing discomfort of the throat, lips, and tongue, as the small spines are easily lodged in the skin. Native Americans like the Tequesta would roll the fruit around in a suitable medium (e.g. grit) to "sand" off the glochids. Alternatively, rotating the fruit in the flame of a campfire or torch has been used to remove the glochids. Today, parthenocarpic (seedless) cultivars are also available.
In Mexico, prickly pears are often used to make appetizers, soups, salads, entrees, vegetable dishes, breads, desserts, beverages, candy, jelly, and drinks. The young stem segments, usually called nopales, are also edible in most species of Opuntia. They are commonly used in Mexican cuisine in dishes such as huevos con nopales (eggs with nopal), or tacos de nopales. Nopales are also an important ingredient in New Mexican cuisine. In 2009 it was introduced as a cheaper alternative to corn for the production of tortillas and other corn products.
Opuntia ficus-indica has been introduced to Europe, and flourishes in areas with a suitable climate, such as the south of France and southern Italy: In Sicily, they are referred to as fichi d'India (Italian literal translation of Indian fig) or ficurinia (Sicilian dialect literal translation of Indian fig). In Sardinia, they are called figumorisca - Moorish figs). They can be found also in the Struma River in Bulgaria, in southern Portugal and Madeira (where they are called tabaibo, figo tuno, or "Indian figs"), in Andalusia, Spain (where they are known as higos chumbos).
In Greece, it grows in such places as the Peloponnese region, Ionian Islands, or Crete, and its figs are known as frangosyka (Frankish, i.e. Western European, figs) or pavlosyka (Paul's figs), depending on the region. In Albania, they are called fiq deti translated as 'sea figs', and are present in the south-west shore. The figs are also grown in Cyprus, where they are known as papoutsósyka or babutsa (shoe figs).
The prickly pear also grows widely on the islands of Malta, where it is enjoyed by the Maltese as a typical summer fruit (known as bajtar tax-xewk, literally 'spiny figs'), as well as being used to make the popular liqueur known as bajtra. The prickly pear is so commonly found in the Maltese islands, it is often used as a dividing wall between many of Malta's characteristic terraced fields in place of the usual rubble walls.
The prickly pear was introduced to Eritrea during the period of Italian colonisation between 1890 and 1940. It is locally known there as beles and is abundant during the late summer and early autumn (late July through September). The beles from the holy monastery of Debre Bizen is said to be particularly sweet and juicy. In Libya, it is a popular summer fruit and called by the locals Hindi, which literally means Indian.
In Morocco, Tunisia, Libya, Saudi Arabia, Jordan, and other parts of the Middle East, prickly pears of the yellow and orange varieties are grown by the side of farms, beside railway tracks and other otherwise noncultivable land. It is sold in summer by street vendors, and is considered a refreshing fruit for that season.
Tungi is the local St. Helenian name for cactus pears. The plants (Indian fig opuntia) were originally brought to the island by the colonial ivory traders from East Africa in the 1850s. Tungi cactus now grows wild in the dry coastal regions of the island. Three principal cultivars of tungi grow on the island: the 'English' with yellow fruit; the 'Madeira' with large red fruit; and the small, firm 'spiny red'.Tungi also gives its name to a local Spirit distilled at The St Helena distillery at Alarm Forest, the most remote distillery in the world, made entirely from the opuntia cactus.
Phytochemicals and folk medicine 6
Opuntia contains a range of phytochemicals in variable quantities, such as polyphenols, dietary minerals and betalains. Identified compounds under basic research include gallic acid, vanillic acid and catechins, as examples. The Sicilian prickly pear contains betalain, betanin, and indicaxanthin, with highest levels in their fruits.
In Mexican folk medicine, its pulp and juice are considered treatments for wounds and inflammation of the digestive and urinary tracts, although there is no high-quality evidence for any clinical benefit of using opuntia for these purposes.
Prior to modern medicine, Native Americans and Mexicans primarily used Opuntia as a coagulant for open wounds, using the pulp of the stem either by splitting the stem or scraping out the pulp.
In one recent study, it was found that Opuntia aided in the prevention or slow down of diabetes, obesity, metabolic syndrome, cardiovascular disease, and some cancers. The results of the group that was taking Opuntia showed a reduction in BMI, body composition, and waist circumference when compared to the placebo group.
Other uses 6
Dactylopius coccus is a scale insect from which cochineal dye is derived. D. coccus itself is native to tropical and subtropical South America and Mexico. This insect, a primarily sessileparasite, lives on cacti from the genus Opuntia, feeding on moisture and nutrients in the cactus sap. The insect produces carminic acid, which deters predation by other insects. The carminic acid can be extracted from the insect's body and eggs to make the red dye.
Cochineal is used primarily as a redfood colouring and for cosmetics. The cochineal dye was used by the Aztec and Maya peoples of Central and North America, and by the Inca in South America. Produced almost exclusively in Oaxaca, Mexico, by indigenous producers, cochineal became Mexico's second-most valued export after silver. The dyestuff was consumed throughout Europe, and was so highly valued, its price was regularly quoted on the London and Amsterdam Commodity Exchanges.
The biggest producers of cochineal are Peru, the Canary Islands, and Chile. Current health concerns over artificial food additives have renewed the popularity of cochineal dyes, and the increased demand is making cultivation for insect farming an attractive opportunity in other regions, such as in Mexico, where cochineal production had declined again owing to the numerous natural enemies of the scale insect.
Apart from cochineal, the red dye betanin can be extracted from some Opuntia plants themselves.
Cactus is used as a fodder crop for animals in arid and dryland regions.
The thick skin of nopal cactus can be harvested as an environmentally-friendly leather replacement.
Bioethanol can be produced from some Opuntia species.
Nopal juice can be used to produce bioplastic.
Sources and Credits
- (c) cammu, some rights reserved (CC BY-NC-ND), http://www.flickr.com/photos/31388721@N00/194107993
- (c) RODOLFO PINEDA PÉREZ, some rights reserved (CC BY-NC), uploaded by RODOLFO PINEDA PÉREZ
- (c) Heriberto Ávila-González, some rights reserved (CC BY-NC), uploaded by Heriberto Ávila-González
- (c) junyor, some rights reserved (CC BY-NC), uploaded by junyor
- Adapted by Desmon M Dunn from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Opuntia
- (c) Wikipedia, some rights reserved (CC BY-SA), https://en.wikipedia.org/wiki/Opuntia
