Anyone who has eaten lotus root knows that when you cut it open, you can see many small holes inside, just like a small arm. However, in the eyes of most people, this is just its unique "appearance". But if you think about it more carefully, why don't most plants have these peculiar small holes in their stems, and what special biological significance do these small holes have for the growth of lotus root? These questions may not be easy for everyone to answer.
The reason why lotus root has this feature is mainly related to its living environment. Those who are familiar with lotus know that it is not only a beautiful flower plant, but also a special economic plant in the water towns of southern China. Lotus grows in freshwater lakes or ponds, with its leaves protruding above the water surface, but its stems are hidden in the mud under the water. Since plants need air for growth, and the mud under the water is precisely the place where air is most lacking. To adapt to this special growth environment, the underground stems of lotus - lotus root - have specialized channels running through the beginning and end of each section, which botanists call air holes. Their main function is to transport the air obtained from the leaves to various parts of the stem.
Coincidentally, mangroves living in coastal swamps also face the problem of lack of air, but their adaptation methods are different from those of lotus root. To support their own bodies, most of the roots of mangroves are buried in the mud. However, to obtain the oxygen necessary for survival, mangroves will expose some of their roots to the air to breathe oxygen directly, so these roots are called respiratory roots.