Function of thorn

The cactus thorn, which may seem meaningless to us, is of great significance to the cactus itself. It is the product of a protective mechanism to adapt to the harsh climate

Usually, most of the water absorbed by the plant is consumed by transpiration. According to the research of scientists, for every 100 grams of water absorbed by the plant, 99 grams are lost due to transpiration, and only 1 gram is saved in the plant, and the leaf is the main transpiration part. Most of the water is lost from here. The larger the leaf area, the faster the evaporation will be

Therefore, in order to survive in the cool drought and retain as much water as possible, after a long period of evolution, the leaves of cactus gradually evolved to adapt to the environment, forming the needle thorn we see now. This evolution fundamentally reduced the transpiration surface of the plant, saved a lot of water consumption, and greatly improved the survival ability of cactus in areas with serious water shortage. The dense thorns we see actually belong to the leaves of cactus

Evolution of thorn

At this stage, the spines of many cactus have changed into other forms, and some have changed into white hairs, which are densely covered on the plant surface, which can reflect strong light and reduce the body surface temperature. At the same time, it also greatly reduces the loss of water, and can store a large amount of water in the plant. In addition, the number, shape, arrangement, color and other changes of cactus thorns are diverse, which not only has unique ornamental value, but also becomes an important basis for us to identify cactus species