Cactus adapted to survive in a desert

Cactus are a unique type of plant that can only be found in highly hot conditions such as deserts. Indeed, no other plants are capable of withstanding the severe heat and lack of water found in these conditions. A cactus is a member of the plant family Cactaceae, which includes approximately 127 genera and approximately 1750 recognised species of the order Caryophyllales. Cacti are a type of succulent. It is believed that the word cactus stems from the Ancient Greek word o, which was initially applied by Theophrastus to a prickly plant whose identity is still unknown. Cacti can be found in a variety of forms and sizes, depending on the species. Despite the fact that some species of cacti thrive in extremely humid situations, the vast majority of cacti are found in regions that experience at least some drought. Many live in extremely arid conditions, with some even being found in the Atacama Desert, which is considered to be one of the driest places on the planet by some.

The following are a few examples of these adaptations in brief:-

Spines

If you were to examine closely at a cactus, you would see that it does not have any structures that resemble leaves. It is instead converted into spines, which arise from little bumps on the plant known as areolas, which originate from the plant’s leaves. 

Photosynthesis is therefore not carried out by the leaves, but is instead carried out by the stems of the plants. Furthermore, because cacti are typically located in desert environments, it is simple for the stem to gain access to sunshine.

Furthermore, the spines help to avoid excessive evaporation, which is important in a desert where water is scarce. Additionally, the spines trap air, which inhibits airflow and prevents evaporation from transpiring through the plant. Another significant purpose of the spines is to collect dew from the early morning fog, which is a very important function. 

The dew that has been accumulated has liquefied and is dripping to the ground below. The plant then takes up the water and uses it for its own purposes. Cactus flesh is extremely succulent, and herbivores in the desert may be enticed to feast on it because of its high nutritional value. These animals are discouraged from doing so by the spines.

Roots that are too shallow

You might think that cacti develop deep roots in order to collect water. This, however, is a fallacious assumption. Although the desert is a dry environment, it does receive some rainfall from time to time. These plants have short roots that typically cover a broad area in order to collect rainwater from the ground, which they use to water their flowers. Furthermore, during the rainy season, cactus roots have sudden growth surges, with some reaching as much as two feet in a matter of hours. Following the rains, these temporary roots wither and die off.

Stomata in the deepest layer

Instead of being present on the surface, cacti contain stomata that are deep into the tissue. Furthermore, the stomata open at night, a photosynthetic adaptation known as Crassulacean acid metabolism, which allows the plant to capture more sunlight (CAM). This, combined with the deep-layer stomata, results in a large reduction of water loss, which is critical in arid environments.

Stem that is both thick and expandable

Because cactus stems are thicker than those of other plants, it is able to retain water in its stems – specifically in collapsible water-storage cells – allowing it to survive in dry conditions To contain more water, the stems can be extended greatly.

Skin that is waxy

A waxy coating covers the bulk of the plant’s surface (except for the stomata).This assists the plant in preventing excessive evaporation while also retaining moisture.

Growing Season Is Limited

Water is required for constant growth, which is difficult to do in dry conditions such as deserts where water is scarce. Thus, cactus have a relatively limited growing season when compared to other plant species. In reality, the plants develop for one season before ceasing growth and resuming growth the following season. Furthermore, cacti develop at a slower rate than other plants, but they live for a longer period of time.

Conclusion:

From the following article we can conclude that Cactus spines are made up of specialised structures known as areolas, which are a type of severely reduced branch in their own right. Cacti are distinguished by the presence of areoles. Areoles, in addition to producing spines, also produce flowers, which are often tubular and multi petalled. In part, this is due to the fact that many cacti have short growing seasons and extended dormant periods, and they are therefore able to respond fast to any rainfall, aided by a large but relatively shallow root system that swiftly absorbs any water that reaches the ground surface.