Plants are one of the main forms of life, including familiar organisms such as trees, shrubs, vines, grasses, ferns, green algae, lichens and so on. Plants can be divided into seed plants, algae, bryophytes, ferns, etc. it is estimated that there are about 450000 species. Most of the energy of green plants is obtained from sunlight through photosynthesis. Temperature, humidity, light and fresh water are the basic needs of plant survival. Angiosperms have six major organs: root, stem, leaf, flower, fruit and seed. Green plants have the ability of photosynthesis - with the help of light energy and chlorophyll, under the catalysis of enzymes, they use water, inorganic salts and carbon dioxide to carry out photosynthesis, release oxygen and produce organic substances such as glucose for plant use.