Ban Ze/Wen
The lotus root is broken and the thread is connected, which is an idiom that almost everyone knows. This idiom comes from a natural phenomenon, that is, when a fresh lotus root is broken, although the main body has been completely separated, there are still many filaments connected together at the broken point.
If we put the filament under a microscope and observe it, we can discover the mystery. It turns out that every lotus root thread we can see with the naked eye is not cylindrical, but flat. It is composed of 3-8 thinner threads. This thinner wire coils like a spring and is extremely malleable.
So, what is the structural organization of the tough filaments? Botanists tell us that it is a transportation system called a duct, which is specially used to transport water and inorganic salts. The inner walls of the plant's vessels are thickened in some places and take on various shapes, such as a ring-like trapezoid or an A-shape. The duct wall of the lotus root is very special. The thickened part is spiral-shaped. Once the lotus root is broken, the thickened spiral part of the inner wall of the duct will break away and form a spiral filament with a diameter of only a few microns. Under the action of external force, these filaments will turn into elongated "micro springs" that will not be broken within a certain elastic limit, and their ultimate length can reach 10 centimeters.
In fact, not only are there threads in the lotus root, but also other parts of the lotus, such as leaves and petioles, are connected by filaments after they are broken off. However, some filaments are extremely tiny and cannot be compared with lotus root filaments.