A cactus is a member of the plant family Cactaceae[a], which has about 127 genera and about 1750 recognized species. Cactaceae belongs to the order Caryophyllales. [4] The Latin word “cactus” is derived from the Ancient Greek word “kktos,” which Theophrastus first used to refer to a spiky plant whose identify is currently unknown. [5] There are many different sizes and shapes of cacti. Most cactus reside in settings that experience at least some drought, despite the fact that some species can tolerate fairly humid situations. Many of them can even be found in the Atacama Desert, one of the driest places on Earth, where they exist in extremely dry circumstances. Cacti have developed a variety of adaptations to conserve water as a result. As an illustration, nearly all cacti are succulents, which means that their swollen, fleshy sections are designed to store water. Unlike many other succulents, most cacti only have a stem where this crucial process occurs. The majority of cacti species no longer have actual leaves; instead, they only have spines, which are heavily modified leaves. Spines help limit water loss by slowing air movement around the cactus and offering some shade, in addition to protecting it from herbivores. Photosynthesis is performed by cacti’s expanded stems in the lack of real leaves. Except for Rhipsalis baccifera, which also grows in Africa and Sri Lanka, all of the Americas, from Patagonia in the south to sections of western Canada in the north, are home to cacti.
Areoles, a type of greatly shortened branch, are specialized structures that create cactus spines. Cacti can be identified by their areoles. Areoles also produce multipetalled, tubular blooms in addition to spines. Because many cacti have extended dormant periods and short growing seasons, they may respond fast to any rainfall. This is made possible by their large but shallow root systems, which swiftly absorb any water that reaches the ground surface. Because cactus stems are frequently ribbed or fluted, they can easily stretch and contract to quickly absorb water after rain and then hold onto it during protracted droughts. The majority of cacti use a unique process called “crassulacean acid metabolism” (CAM) as part of photosynthesis, similar to other succulent plants. Unlike photosynthesis, which occurs during the day, transpiration—during which carbon dioxide enters the plant and water escapes—occurs at night. The plant converts the carbon dioxide it absorbs into malic acid and stores it there until daybreak, when it is solely used for photosynthesis. The cooler, more humid nighttime hours are when transpiration occurs, which greatly reduces water loss.
The globe-shaped stems of many smaller cacti combine the maximum volume of water storage with the smallest surface area of transpiration loss. The largest[b] free-standing cactus is Pachycereus pringlei, which reaches a maximum height of 19.2 m (63 ft)[7], while Blossfeldia liliputiana has the lowest diameter at maturity, measuring just around 1 cm (0.4 in). [8] During a downpour, a mature saguaro (Carnegiea gigantea) is believed to be capable of soaking up 200 US gallons (760 l; 170 imp gal) of water. [9] Only a few species look significantly like the rest of the family. Plants belonging to the genera Leuenbergeria, Rhodocactus, and Pereskia resemble nearby trees and bushes, at least on the surface. They have enduring leaves and, as they age, stems covered with bark. Despite their appearance, they are recognized as cacti by their areoles and have numerous water-saving adaptations. Leuenbergeria is thought to be very closely related to the original species from which all cacti descended. Other cacti develop as forest climbers and epiphytes in tropical areas (plants that grow on trees). Their stems often have fewer or even no spines and are flattened, almost leaf-like in appearance, like the well-known Christmas or Thanksgiving cactus (in the genus Schlumbergera).
Many types of cacti are produced as beautiful plants, while others are raised for fodder or forage, and yet others are utilized as food (particularly their fruit). An bug that lives on some cactus produces cochineal.
Many succulent plants, both in the Old and New Worlds, have spiky stems, including some members of the Euphorbiaceae (euphorbias), which is why they are frequently mistakenly called “cactus.”
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What makes the cactus significant?
Any member of the flowering plant family Cactaceae that is native to North and South America and is characterized by reduced-sized or ephemeral leaves, enlarged plant stems, and spines that develop from areoles—a structure specific to cacti—is referred to as a cactus (plural cacti, cactuses, or cactus). With 2,000 to 3,000 species, cacti are distinctive and odd plants. Most have numerous unique adaptations to survive and grow in hot, dry circumstances because they reside in desert or semi-arid habitats.
Many desert species depend on cacti as a source of food and water, and they play a significant part in the ecology of the desert. Since the beginning of time, some cactus species have been used by humans for food and medicine among other things. They are also widely used as indoor and outdoor plants. Some species have become endangered due to human activity, while others have caused issues when they were introduced to regions where they are not native.
What makes it a cactus, and why?
(Above) The cardoon’s spiny heads, which may have originally been called “cactus,” and (Below) A melocactus, probably the first genus seen by Europeans.
Since the first cacti were found for scientific study, naming and classifying them has been a challenging and contentious process. Carl Linnaeus is credited with causing the problems. He divided the cacti he was familiar with into the genera Cactus and Pereskia in 1737. However, he consigned them all to the genus Cactus when he published Species Plantarum in 1753, which served as the foundation for contemporary botanical classification. The term “cactus” is derived from the Ancient Greek “kaktos,” which Theophrastus used to refer to a spiky plant that may have been the cardoon (Cynara cardunculus). [27]
After being separated into multiple genera by later botanists like Philip Miller in 1754, Antoine Laurent de Jussieu in 1789 included these genera in his newly discovered family Cactaceae. By the early 20th century, botanists had come to the conclusion that Linnaeus’s word Cactus should not be used as a genus name since it had grown so unclear as to its meaning (was it the genus or the family?). The Mammillaria genus was designated as the type genus of the family Cactaceae by the Vienna Botanical Congress in 1905, which rejected the name Cactus. On the other hand, it preserved the name Cactaceae, which resulted in the peculiar circumstance that the family Cactaceae no longer included the genus after which it was named. [28]
The challenges persisted, in part because “type specimens” are necessary for assigning scientific names to plants. In the end, botanists should be able to compare a plant to the type specimen to which this name is inextricably linked to determine whether it is an example of, say, Mammillaria mammillaris. Compression and drying are typically used to make type specimens, which are then kept in herbaria as indisputable records. Cacti, on the other hand, are particularly challenging to preserve in this manner because they have developed the ability to withstand drying and their bodies do not easily compress. [29] Another issue is that, rather than being named by botanists, many cacti were given names by horticulturists and growers. As a result, the rules of the International Code of Nomenclature for Algae, Fungi, and Plants, which controls the names of cacti and other plants, were frequently disregarded. David Hunt claims that Curt Backeberg in particular is credited with having named or renamed 1,200 species without ever having one of his names associated with a specimen. As a result, Backeberg “created a trail of nomenclatural disorder that will undoubtedly vex cactus taxonomists for years,” says Hunt. [30]
From where is the cactus?
Cactus, often known as cacti or cactuses, belongs to the order Caryophyllales and is a family of flowering plants with about 2,000 species and 139 genera. From British Columbia and Alberta southward, cacti are native to most of North and South America; the southernmost portion of their distribution reaches deep into Chile and Argentina. The highest number and variety of species are found in Mexico. The only cactus that might be native to the Old World are Rhipsalis species, which are found in Sri Lanka, Madagascar, and East Africa. Few cactus species exist in tropical or subtropical climes, although the majority do and are well adapted to dry conditions. List of Cactaceae plants is also available.
What is a Class 4 cactus?
Desert plants include cactuses and other cacti. They thrive in arid environments where other plants struggle to survive. They survive because of their capacity to hold water. Sharp spines or needles on cacti serve as additional protection. These make animals less likely to eat them.
How do cacti develop?
Rain forests and even Canada’s far north are home to cacti. However, their most amazing characteristic is their capacity to flourish in the desert, where rain occurs sporadically and erratically.
By working evenings, finding alternate ways to get energy, and maintaining a bag of sour tricks.
The cactus have developed a wide range of adaptations to live in the desert, according to Erika Edwards, a plant evolutionary researcher.
The saguaro, or Carnegiea gigantea, is one of the most recognizable cacti. However, they only flourish in the Sonoran Desert, where they can be seen growing tall in a small area of southern Arizona, northern Mexico, and southeastern California.
According to research by Edwards and Michael Donoghue of Yale University, leafy shrubs and trees of the Pereskia genus originally exhibited some of these water-saving characteristics over 20 million years ago.
The journal American Naturalist reported the findings in its June issue.
Stomata are tiny skin pores that open and close on all plants to capture carbon dioxide. Plants convert the carbon dioxide they have gathered into nourishment in the form of carbohydrates during photosynthesis. Water escapes from the pores every time they open, making the process challenging in the desert.
It’s hazardous business to open the pores and lose water if you’re attempting to conserve water, Edwards told LiveScience.
Cacti and other nocturnal plants, including agaves and aloes, open their pores at night while most plants open their stomata during the day.
Cacti are able to hold onto water because of the cooler temperatures, lack of sunlight, and quieter breezes.
In order to thrive in their harsh environments, cacti have also evolved succulent tissue, waxy skin, prickly spines, and a unique root system.
- The stem serves as a reservoir, and depending on how much water it contains, the plant will grow and shrink.
- The waxy layer of the skin keeps moisture in.
- The sharp spines defend against animals asking for a free sip out of thirst.
Some cacti have spines that also catch raindrops and deliver the valuable liquid to the plant’s roots.
You might imagine that cactus would develop extensive root systems to look for a steady source of groundwater. Instead, they frequently form large, shallow root systems that reach several feet away from the plant, sit just below the Earth’s surface, and are ready to collect as much water as possible.
When it rains, cacti shoot out new roots. To conserve the plant’s water supply during dry times, roots will shrink and split off.
According to Edwards, “the cactus becomes more hydrated than the soil it is growing in.” It must cut its connection to the soil since it faces the risk of losing water to the soil.
Even lacking the morphological peculiarities of the typical leafless cacti, leafy cacti like the Pereskia and other plants have evolved comparable water-saving features and reside in the desert.
It’s solid proof that the tactic is effective, according to Edwards. “The plants thrive very well in these conditions.”
What three purposes do cacti serve?
NARI recently gave 200 kg of fresh cladodes—the flattened organ that grows from a plant’s stem—to farmers in the Andhra Pradesh district of Medak. Numerous other institutions in India have also conducted studies on this plant.
It would be fantastic if farmers began experimenting with it as Nandini Nimbkar continues to raise awareness about this great crop.
What represents cacti?
Native American cultures view the cactus as a symbol of warmth, safety, and maternal love. Cacti have come to represent unconditional, maternal love because of their ability to withstand adverse environments.
A cactus helps the environment in what ways?
In hot regions, cacti frequently serve as “nurse plants,” providing shade and occasionally nutrients that aid in the establishment of seedlings of other species that might not be able to do so in hot or poor soil.
Is a cactus a tree or a plant?
The cactus species are part of a family that includes over 127 plant genera and over 1700 different species of cacti. The moon cactus is an example of a species of these cacti that can also sprout flowers or that already have blooms on their tops.
Cacti aren’t actually trees, even though they have stems that resemble trees. It is obvious that cactus plants are different from trees since their stems are flexible rather than woody. A cactus cannot be regarded as a tree because the smaller cacti are also rather little and lack even a fraction of a tree’s height. Succulent plants include cacti. There are several succulents, including cacti. The simple method to tell if something is a cactus is to look at its spines. Although cacti can produce flowers, this does not qualify them as blooming plants. There are more than a thousand different species of cactus, and each one is unique from the others. However, a plant can only be called a cactus plant if it possesses a precise set of characteristics. A succulent’s skin surface is different if it contains a stem, which can store water, making it impossible for these plants to lose water. The plant’s spines are another factor in the argument over whether it is a cactus. Although certain cacti are also referred to as flowering plants, their physical characteristics differ from those of other cacti.
What is the cactus’ past?
The majority of plants from the New World are cacti. This indicates that only North America, South America, and the West Indies are home to them. Rhipsalis baccifera, a species with a pantropical distribution that can be found in tropical America as well as Old World tropical Africa, Madagascar, and Sri Lanka, is the sole exception. This plant is believed to have only recently colonized the Old World (within the last few thousand years). Its seeds were likely transported there by migratory birds. After being introduced by humans to comparable habitats in other regions of the world, many additional cacti have naturalized there.
It is thought that cacti have just been around for the past 30–40 million years. The Americas were once connected to the other continents, but continental drift caused them to separate. The New World’s distinctive species must have evolved after the continents split apart. Only in the last 50 million years have the continents moved significantly apart. The fact that the continents had already separated when cactus developed may help to explain why they are so uncommon in Africa. Many succulent plants, both in the Old and New Worlds, resemble cacti greatly and are frequently referred to as “cactus” in everyday speech. However, none of these are closely linked to the Cactaceae and this is because of parallel evolution.
In order to create a cochineal dye industry and serve as a natural agricultural fence, prickly pears (genus Opuntia) were brought to Australia in the 19th century. However, they soon spread like wildfire and became a major weed. For local herbivores, this invasive species is toxic, and it has rendered 40,000 km2 of arable ground unusable.