The scientific name of lotus is lotus, which belongs to the genus Nelumbo of Nymphaeaceae.
Lotus. It is one of the earliest angiosperms. According to the fossils studied by paleobotanists, lotus plants were distributed in many waters in the northern hemisphere10.35 billion years ago. At that time, in the late period of the rapid decline of the giant reptile dinosaur, it grew on the earth much earlier than the appearance of human ancestors (2 million years ago). According to the Paleobotany (1965) written by A.H. Christophevich of the former Soviet Union, lotus fossils were found in Cretaceous strata in the Arctic region of North America and the amur river Valley of Asia (i.e. Heilongjiang), and also in Oligocene and Miocene strata in Europe and East Asia (Sakhalin Island) and Japan. At that time, the temperature on the earth was warmer than it is now. There were about 10~ 12 species of lotus plants distributed in five continents. With the arrival of post-Ice Age, the global temperature dropped, which made many plants extinct, while others were forced to drift away, completely breaking the original geographical distribution. Because of this disaster, two species of lotus survived, and their distribution range narrowed. Chinese lotus (Nelumbo nucifera) is distributed in Asia and northern Oceania, and drifted to Huang Lian in North America. Paleobotanists also pointed out that the lotus fossils excavated in Hokkaido and Kyoto from Pleistocene to Holocene (2 million years ago) are similar to modern China lotus; The lotus leaf fossils excavated in Qaidam Basin, China, 6,543,800 years ago are similar to those of modern China lotus. In 1970s, China Institute of Petroleum Exploration and Development Planning, Ministry of Petrochemical Industry and Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences recorded in the book "Early Tertiary Sporopollen in Coastal Areas of Bohai Sea" that two kinds of lotus pollen fossils were found in Panshan, Liaoning, Beidagang, Tianjin, Kenli, Guangrao, Shandong and Cangzhou, Hebei. Fossils of the genus Nelumbo were also found in the strata of Changchang Basin in Qiongshan, Hainan Island, China, in the Tertiary tropical phytogeographical region. At present, the original wild lotus is still distributed in lakes and swamps in Fuyuan, Hulin, Tongjiang and Shangzhi counties of Heilongjiang Province. The above shows that lotus is an ancient plant before the Ice Age, and it belongs to the representative of relict plant, such as Paeonia suffruticosa, Ginkgo biloba, Liriodendron chinense in China and Sequoia sempervirens. They survived without being swallowed up by the glaciers of the Ice Age.
Mystery of waterproof and self-cleaning of Erlianye
Numerous micron-sized waxy papillary structures are attached to the surface of lotus leaves. When observing these papillae with electron microscope, we can see that there are many nanoparticles with similar structure attached to the surface of each micron-sized papillae, which scientists call the micro-nano dual structure of lotus leaf. It is these tiny double structures that make the contact area between the lotus leaf surface and water droplets or dust very limited, so there is a phenomenon that water droplets roll on the leaf surface and take away dust. And water will not stay on the surface of the lotus leaf.
Scientific explanation of three kinds of fracture relations
When it comes to lotus, it is natural to mention lotus root. Holland belongs to Nymphaeaceae, a perennial herb planted in shallow ponds. Its stem was born in the mud and transformed into rhizome, that is, lotus root, also called lotus root. Lotus root grows horizontally in the mud and absorbs nutrients by fibrous roots on the base stem. Lotus root has been a favorite food since ancient times, because its meat is crisp and tender, slightly sweet, contains a lot of starch and is rich in nutrition.
When we break the lotus root, we can observe countless long white lotus roots connected between the broken lotus roots. Why is there such a phenomenon?
It is necessary to observe the structure of lotus root. Originally, 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 in a certain part, forming various textures, some of which are annular, some are trapezoidal and some are reticulate. However, 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 exists not only in lotus root, but also in lotus stalk and lotus leaf, but it is more slender. If you pick a lotus stalk, try to break it into several pieces and hold it up like a long string of small green lanterns. It is this filament that connects these little green lanterns. This kind of filament looks like one. If you look 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 and lingering lotus root silk has already attracted the attention of the ancients. There is a saying in Meng Jiao's poem Qufu in the Tang Dynasty that "my heart is broken". Later, people used the idiom "broken silk" to describe that although the relationship broke down, love was still connected.