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.
Why are there thorns on cacti?
I had always thought cacti had spines for defense, but it turns out they serve a variety of other purposes and are quite extraordinary adaptations. In a variety of intriguing ways, they aid cacti in surviving the challenges of desert life.
The purpose of cacti’s spines By serving a variety of purposes, spines enable cactus to survive and even thrive in arid settings. They shield the plant from predators, offer shade, aid in temperature control, lessen water loss, and even encourage the plant to spread and procreate.
Continue reading to learn more about how cactus use their spines to help them survive and grow in the harsh environments where they reside.
What caused cacti to develop spikes?
The majority of cactus species lack genuine leaves and branches. They feature tiny bumps called areoles, which are highly modified branches from which spines grow, instead. A cactus’ spines are significantly altered leaves.
However, why would a plant switch from photosynthesizing leaves to spiky protrusions?
Cacti are able to achieve this in part because their stems are capable of photosynthesizing. Like an oak tree, they don’t require leaves. Additionally, they typically grow in places with lots of sunlight!
What do the cacti’s thorns represent?
a species of Opuntia with glochids and spines. The glochids are the tiny prickles at the center of the bunches, whereas the spines are the relatively big, radiating organs.
Glochids, also known as glochidia (plural “glochidium”), are small, usually barbed spines or prickles that are present on the areoles of cacti belonging to the Opuntioideae subfamily. Glochids from cacti quickly separate from the plant and ensnare in the skin, irritating it when they come into touch. Some cactus species have tufts of glochids in the areoles that nearly completely cover the stem surfaces, with each tuft containing hundreds of glochids. These tufts may exist in addition to or in place of the larger, more noticeable cactus spines, which are typically not barbed and are difficult to detach.
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.
Published: January 3, 2013
The way that the seasons affect how we view (and value) plants is one of the fascinating parts of enjoying them. The seasons that plants are most appealing to most ardent gardeners are likely to be spring, summer, or fall, and this is for obvious reasons. However, certain deciduous (often woody) plants have benefits that are most noticeable in the winter after the leaves have fallen. This is when unique plant characteristics that were concealed during the growing season become evident, bringing interest to the landscape.
The whitish-colored bark on the higher branches of the American sycamore is one illustration of the aforementioned. Compared to the summer, it is considerably more noticeable when the leaves have fallen. The same might be said for plants like cranberry-bush viburnum, winterberry holly, and flowering crab apple that produce bright fruit. Thorns, spines, and prickles are distinctive appendages some plants grow that make them more intriguing (if not appealing) throughout the winter, despite being less visually dominating than the preceding examples.
Most people mistakenly believe that any plant with a pointy protrusion is a thorn. This makes sense considering that the majority of people are familiar with roses and the pointed (and occasionally painful) “thorns” they contain. However, roses only have prickles rather than actual thorns. Depending on where in the plant they originate, these pointed projections are classified differently in a botanical sense.
The term “thorn” is only properly used to describe a sharp-pointed structure that is a modified branch. At the leaf axils, thorns frequently emerge from the main stem. Firethorn (Pyracantha), hawthorn, and Japanese blooming quince are thorny landscape plants.
A “spine” is a pointed protrusion that grows from a leaf, stipule, or other leaf component rather than from a branch. The most notorious woody plant with spines, which frequently exist in compound form, is arguably the honey locust. This species’ spines are so dangerous that a botanical version without them is employed for landscaping. Barberry and black locust are two additional common landscaping plants with spines.
In cacti, the plant’s entire leaf gets changed into a spine. This particular adaptation shields the succulent stem of the plant from animals that might exploit it as food or a source of water in addition to decreasing water loss by limiting leaf surface area.
Only the edges of the leaves of other plants have spines. Good examples of the latter include Oregon grape-holly, American holly, and English holly.
A prickle is the third kind of pointy protrusion that can be seen on plants. Prickles are expansions of the cortex and epidermis that grow from stem tissue. A prickle sounds less dangerous than a thorn or a spine, possibly because it almost rhymes with the word “tickle.” Sometimes this is not the case. The rose is unquestionably the most common garden plant with prickles, and most ardent gardeners have experienced more than one painful or unlucky brush with its sharp protrusions. Other examples of prickle-bearing plants include devil’s walking stick (Aralia spinosa) and prickly ash (Zanthoxylum americanum).
The function of thorns, spines, and prickles in nature is to defend plants against potential predators. Any intelligent herbivore won’t likely attempt to nibble at a species like barberry more than once. Sadly, depending on the type, growing plants in the landscape that have thorns, spines, or prickles might be dangerous to some extent.
The majority of plants with thorns, spines, or prickles are safe when utilized as backdrop or border plants or when tree branches are pruned well above head height. They also provide the winter landscape a distinctive character and can act as a solid barrier to increase the security of our house and its belongings. However, they can be a safety issue when positioned in the environment where people frequently walk or drive by, especially to youngsters and pets. By choosing, arranging, and maintaining them with care, you can prevent unpleasant encounters and improve the landscape’s visual appeal.
What function do plant thorns serve?
The main purpose of thorns, spines, and prickles is to mechanically inhibit herbivory. They are therefore categorized as mechanical or physical defenses rather than chemical defenses.
The defense against physical attacks by herbivores and other animals is not the only purpose of spines or glochids. Spines have been demonstrated in some instances to shade or insulate the plants they grow on, shielding them from high temperatures. For instance, the apical meristem of saguaro cacti receives summertime shading from the spines, and wintertime insulation from glochids in Opuntioideae plants.