Is it true that spines replace cactus leaves, and why else are they needed?

Over thousands of years of evolution, cacti have become completely unique plants that can survive even in the most extreme climatic conditions.

Their main distinguishing feature, of course, are thorns, the variety of forms and types of which is amazing. The article will explain in detail why the cactus needs needles, and what is the use of them for the life of the plant.

Is it true that needles are leaves?

There are several theories about what the thorns are, including one that says that it is nothing more than leaves modified in the process of adapting to environmental conditions, in which only the middle fibers are preserved. But it’s more correct to consider needles as evolving kidney scales.

Why do they need a plant?

Goals for which a great many thorns are needed, here are some of them:

1. To save moisture.

   In an arid climate, every drop of water is worth its weight in gold. In most plants, the process of moisture evaporation occurs through pores on the surface of the leaves.

   The cactus does not have this problem, which allows it to preserve the precious liquid as much as possible.

2. Overheat Recovery.

   The needles of some cacti have changed in such a way that their dense mass obscures the body of the plant from scorching sunlight, creating a shadow and protecting it from too high a temperature.

3. Moisture absorbing function.

   The desert climate, in which many cacti live, has certain characteristics, including sharp temperature fluctuations during the daily cycle. During the day, the temperature can rise above +50 degrees, and at night it can drop to almost zero, while the condensation of moisture in the air occurs, which settles on the ground in the form of dew.

   The cactus spines have a hollow structure and are able to absorb these tiny drops, providing the plant with the necessary amount of fluid.

4. For guard.

   One of the most obvious functions of needles is the protective, sharp, stinging painfully stinging thorns that make the plant extremely unappetizing for most animals, which otherwise would gladly enjoy juicy pulp.

   Not all cacti have thorns that have sharp needles; there are species covered with thin hairs, white fluffs or even feathers (for example, the Mammillaria cactus).

What do the needles of different plant types look like in the photo?

Cacti of the Mammillaria family are not covered with the usual needles, it is not even immediately believed that this is a cactus. For example, the spines of Mammillaria lasiacantha resemble feathers in structure, in Mammillaria egregia they are more like snowflakes, and Mammillaria bocasana is as if wrapped in a white downy cloud. Nevertheless, these are all different forms of thorns that have adapted to the needs of specific types of plants (how not to prick a cactus and what to do if it happened, read here).

In less arid regions, spines bear primarily a protective function., therefore, grow longer and can be located much less frequently. For example, in Cereus jamacaru and Corryocactus brevistylus, the length of the needles can reach 25 cm.

The more arid climate, the shorter and closer to each other are the spines of a cactus. This is due to the fact that the protective function goes by the wayside, and the protection against overheating and excessive evaporation of the liquid becomes much more important.

Non-spiny flower species

Despite the fact that the majority of cactus is associated exclusively with something prickly, this is far from always the case. There are certain types of cacti that do not have thorns, for example:

• Ariocarpus Fissuratus (stone flower);
• Astrophytum caput-medusae (jellyfish cactus);
• Ophophora williamsii (Peyote cactus).

The adaptive mechanism of cacti, created by nature itself, never ceases to amaze. Thanks to the amazing colors, amazing, sometimes almost alien, shapes and severe character, it is simply impossible not to pay attention to cacti.

Watch the video: How Old is That Barrel Cactus? (May 2024).