Looking at the world around us, look at the beautiful white poplars of the sky, the beautiful weeping willow, and the grass that face the breeze frequently. feel. The reason why the big tree is upright is that the grass is not facing the wind because they all have a strong backbone -stems.
The stems of the plants mostly grow on the ground, carrying lush branches, leaves, flowers, and fruits, but also to resist the invasion of wind and rain. Therefore, the stems of the plant have strong support and anti -royal ability. Therefore, most of the stems are cylindrical. However, the stems of some plants are triangular, such as grasses; square columns, such as broad beans and mint; flat column shapes, such as crickets and cactus, so the stems of the plants are actually changing.
When spring is coming, everything recovers, when willow returns to green, you may wish to intercept a tone of the poplar or willow tree with appropriate thickness, which will easily peel off the bark. You will find the peeling off. The inside of the bark is a thin and white thing, which is called the tree of the trees. The remaining part of the bark is tightly white called wood, and most of the stems are occupied. At this time, you can touch the inside of the skin or the outside of the wooden part with your fingers. You will find that your fingers have a smooth and moist feeling. The formation of the formation layer is the decision of the thickness of the stem, because the cells of this layer have a particularly strong split ability, and a small part of the cells that split outward forming a new cashmere part are mainly to form a new wooden part of the cells inward. The cellular cells are added to the original skinny part, and the newly formed wooden cells are added outside the original wooden part. From the horizontal section of the stems, the formation layer seems to be a large leather ring. The area of \u200b\u200bthe wooden part is continuously increased, and the leather ring is continuously expanded, so that the diameter of the trees is thickened. So the thickness of the stem is determined by the magical formation layer. So what are the reasons for the stems of herbal plants?
It turned out that the stems of the herbal plants did not form a circle of wounding stems like trees. The formation layer of the stems was bouquet and scattered in the stems like a star. If you have seen the horizontal cutting surface of the corn's stems, you will see a small yellow dot scattered in the stems, that is to form the part of the layer, and the thickening ability of such stems is very limited. In addition, the life cycle of herbal plants is very short. Most of them end their life within a growing season. When its stems are too late, their lives are over, so their stems are very thin. (Source: Plant Encyclopedia)