Bryophytes are a small world because almost all of their members are dwarfs a few centimeters tall; Bryophytes are a large world because their distribution area covers almost every corner of the land; Bryophytes are both a familiar world and a very unfamiliar world, because although we often come into contact with it, we often pay little attention to it. It can be said that almost everyone has seen such small plants, especially in certain humid environments, where you can often see many very short moss. They are crowded together like a green carpet under your feet.
Many people have once asked this question: Compared with common trees, shrubs and even herbs, moss is too short, generally only 1 to 10 centimeters tall. What is the reason why moss plants cannot grow tall? Did the sorcerer cast a spell? If there is a curse, it is the water transport system.
We know that water is the source of life, and plants are of course inseparable from water. Moreover, the nutrients needed by plants need to be dissolved in water before they can be absorbed by plants. Since the root system of a tree can penetrate several meters or even ten meters underground, it can effectively absorb water and nutrients dissolved in water from the soil, and then transport the water and nutrients to leaves or other parts of the plant body through specialized vascular bundles for growth needs. The vascular bundles in their bodies are like highways extending in all directions, which can quickly and effectively transport water and nutrients to various parts of the plant.
Bryophytes cannot form vascular bundles in the body because they cannot synthesize the lignin used to form vascular bundles. Without vascular bundles, there is no system for transporting water over long distances. Therefore, moss can only absorb water and dissolved nutrients from external environments such as air, dew, and rainfall through stems and leaves. It is precisely because of the limitations of water transport that bryophytes can only be mini and small people in the plant kingdom.