It is necessary to observe the structure of lotus root. It turns out that the tissues needed for plants to grow and transport water and nutrients are called ducts and tracheids. These tissues extend in all directions in plants and are as unimpeded as blood vessels in animals in leaves, stems, flowers, fruits and other organs.
The inner wall of the plant vessel will be particularly thickened at a certain position, forming various textures, some are annular, some are trapezoidal and some are reticulate. The thickened part of the lotus root catheter wall is continuous spiral, which is called spiral catheter. When the lotus root breaks, the spiral part of the inner wall of the catheter is separated and becomes a spiral filament with a diameter of only 3 ~ 5 microns. These filaments are much like stretched springs and will not break within the elastic limit. Generally, it can be stretched to about 10 cm.
Lotus root silk not only exists in lotus root, but also exists in lotus stem and lotus leaf, but is thinner. If you pick a lotus stalk, try to break it into several pieces and lift it like a long string of small green lanterns. It is this filament that connects these little green lanterns. This kind of filament looks very similar. If you look at it under a microscope, you will find that it is actually composed of 3 ~ 8 thinner filaments, just like a cotton yarn is composed of countless cotton fibers.
The delicate lingering of lotus root silk has long attracted the attention of the ancients. There is a sentence in Qufu, a poem written by Meng Jiao in the Tang Dynasty: "My heart is in the lotus root, although it is broken, it is still connected". Later, people used the idiom "broken silk" to describe that although the relationship was broken, the relationship was still connected.