The cactus family is known for its prickly spines, which are actually altered leaves. The kind of leaves that a maple or oak tree has are not present on cacti. But in the distant past, they might have had leaves that were at least somewhat more similar. Due to the fact that they aid the plants in surviving in hot, dry situations, those leaves eventually changed into the prickly spines we see on cactuses today.
“They could serve as a defensive strategy to prevent herbivores, or animals that consume plants, from consuming the cactus. But spines also produce shade! “Kimberlie McCue says.
“When you are covered with spines, those spines are throwing shadows on the cactus’ body as the sun moves across the sky. They are tiny umbrellas for shade.”
All cacti are native to arid regions, and some can even survive in dry climates. How do they acquire water to exist, then? Kimberlie informs us that these plants can be found close to the water.
“There will be fog coming off the ocean in the morning. Water condenses on those spines, forming tiny droplets, which then flow down the spine, to the plant’s body, to the soil, and to the roots.”
As they hold the soil in place and offer shelter to birds and other creatures, cactuses are also crucial components of their desert ecosystems. In exchange, such animals and birds assist in pollinating the cactus flowers. Cacti are a significant local source of food for people.
Cactuses are unfortunately threatened by people who illegally steal natural plants from their surroundings. According to Kimberlie McCue, being cautious when purchasing cactus plants is one method to ensure that cacti remain healthy and numerous. Before you buy, find out where the cactus came from and confirm that the vendor is being a responsible steward of these plants.
Why do cacti lack leaves in favor of spikes?
Cacti have numerous adaptations that enable them to survive in arid climates; these adaptations enable the plant to efficiently gather water, store it for a long time, and conserve it (minimizing water loss from evaporation).
Cacti have thick, succulent stems with rigid walls that store water when it rains. The stems are fleshy, green, and photosynthetic. Either the stem’s inside is spongey or hollow (depending on the cactus). The water inside the cactus is prevented from evaporating by a thick, waxy layer.
Long, fibrous roots are common in cactus, and these roots take moisture from the earth. Some cacti, such as ball cacti, have smaller, more compact roots that can capture dew that falls from the cactus.
Most cacti feature scales or spines in place of leaves (which are modified leaves). These scales and spines do not evaporate their water (unlike regular leaves, which lose a lot of water). Predators (animals that would like to consume the cactus to gain food and/or water) are kept at bay by the spines. On a cactus, areoles are a circular collection of spines. An areole is where flowers bud, and it is also where new stems branch.
How do the thorns on a cactus help it survive?
Being a desert plant, your goal is to prevent water reduction. As strange as it may appear, cactus spines really work to prevent water loss in cacti.
Cactus spines primarily stop cacti from losing water by decreasing air flow around the plant. Air flow is broken up by spines, which can aid in lowering evaporation. A buffer zone with air that is a little bit more humid can also be produced by the trapped air surrounding the cactus.
This is significant because plants lose a lot of water as it evaporates off their leaves.
How do thorns develop on cacti?
Cactus plants have modified leaves that behave as spines. These begin as live spine primordia, mature, and eventually die back to create hard spines. Additionally, cacti have tubercules, which areoles that rest on bases. On lengthy, nipple-shaped tubercles that areoles occasionally have, spines can sprout.
Why are cacti so uncomfortable?
Anyone who has come into contact with a jumping cholla cactus can attest to the fact that it is both excruciatingly painful and challenging to resolve because the cactus’ spines are notoriously difficult to remove.
Cactus spines have a variety of purposes, including defense and the storage of essential water in arid regions, although some are considerably more difficult to remove than others. Researchers have now determined the cause.
Microstructure Matters
The function of the spines, particularly their capacity to pierce animal skin, was tested by Stephanie Crofts and Philip Anderson of the University of Illinois on six different cactus species. Their findings, which were reported in the Proceedings of the Royal Society B, demonstrate that the microstructural characteristics that enhance a spine’s capacity to pierce flesh also raise the barrier to removal.
With their shingled, overlapping barbs, cholla and other barbed cactus spines in particular resemble porcupine quills. Compared to non-barbed spines, these barbs more easily pierce and entangle flesh.
According to Anderson in a news statement, “The barbs grab on your muscle fibers, making it tough to remove them.
The two also experimented with golden barrel, brittle prickly pear, and a few other common cactus species in addition to jumping cholla. They pierced skinless chicken breasts, hog shoulders with the skin still on, and a succession of rubbers with various densities to determine the structure of each plant after studying the spines under a scanning electron microscope to learn more about it. According to their experiments, barbed spines function as razor-sharp blades that may readily pierce skin.
According to Anderson, the cholla spine needs to be able to penetrate the target with just a mild brush in order to puncture the target efficiently. ” It must also be quite challenging to remove at the same time.
An up-close look at a Cholla spine reveals its overlapping barbs, which make removing these spines more challenging and unpleasant. (Credit: Wikipedia/Nebarnix)
Stuck On You
Barbed spines, like cholla, emerged out of the chicken breasts with a tissue-coated exterior. The researchers believe that some of the barbs were left behind in the flesh because they did not emerge clean from the pork samples.
The plains prickly pear’s spines checked out took the most effort to remove from chicken breasts. On the other hand, cholla spines proved to be the most difficult to extract from pig tissue; tests revealed that one cholla spine was capable of hooking into flesh with sufficient force to lift half a pound of pork by the skin.
That’s both quite frightening and clever. Cholla spines also have a reproductive function. Chollas have spines that hook onto a person or animal’s muscle fibers so strongly that it frequently tears off a piece of the cactus, which is then moved to a new area and can start growing as a new plant.
Why are there thorns on plants?
The majority of plants that have spines utilize them to defend themselves against predators, despite evidence to the contrary showing that in several plant groups, such as the cacti, the development of spines was primarily motivated by the need to prevent water loss from leaves.
Why do plants in the desert have thorns?
The thorny plants, like cactus, are attractive to look at but difficult to manage because most people are reluctant to admit they would enjoy having one because of the potential for intense discomfort. Cactus, agave, and mesquite are examples of desert plants that must endure in areas with little water. To live, these desert plants must contend with a variety of strange situations.
Other plants lose moisture through the pores on their leaves and stems, which they have. Therefore, in order to lock in the meager amounts of moisture they have, these desert plants must avoid those pores. As a result, these leaves lack pores and develop hard, dry spines or thorns. By not releasing any moisture at all, these thorns save water. The lower, greener portion of a leaf has the least amount of activity, assisting the plant’s survival. To protect themselves from being nibbled on, the spikes also cover the pores.
- They are short because of a slower development mechanism.
- Desert plants must make efficient use of their limited water supply.
- Even still, they develop much more slowly than typical plants do.
As a result, these clever prickly bushes develop slowly while protecting themselves and preserving resources.
Why do cactus needles fall out?
The majority of cacti contain spines, and having them can help you determine how healthy your plants are. Your cactus won’t appear as attractive if it is losing its spikes or leaves, and depending on the cause, it could even pass away. You may learn the causes of your cactus losing its spines (thorns) or leaves in this post, how to halt it, and how to encourage your cactus to produce new spines.
Pests (particularly mealybug), a lack of nutrients, or fertilization are a few of the main causes of a cactus losing its spines or leaves. Less frequent causes include burns, excessive watering, and inadequate sunlight.
A cactus’ method of defense?
The protection of cacti from predators is one of the spines’ primary roles. Most animals will avoid them because of their sharp spines, but not all. The sharp spines don’t deter javelina (wild pigs), pack rats, desert tortoises, or bighorn sheep since they eat cacti.
Unexpectedly, the cactus itself receives shade from the spines of the plant. It can be difficult to believe at first that the small cactus spines provide any actual shelter from the scorching desert sun. But it is simpler to think that the spines help to protect the surface of cacti when you realize that each spine offers a modest bit of shade and then multiply that by 1,000 or more per cactus. Additionally, the spines lessen water evaporation.
The spines of some Cholla species actually have a second function; they aid in reproduction. Chollas have small barbs at the terminals of their spines that are extremely responsive to adjacent movement. As a result, the cholla’s segments “leap out” and attach themselves to anyone passing by (animal or human). Although they don’t truly “jump,” it sure feels like they do. The dislodged cholla segment will eventually take root in the soil and develop into a new Cholla when it falls to the ground from whatever was dragging it along.
What is a cactus used for?
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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How come cacti are green?
The cactus’ stems are what are green on the plant. The cactus’s stems perform photosynthesis because they are green. In order to keep animals from eating the cactus, they also develop prickly needles.