Interpretation of tree: sound, wood and sound. The original meaning of planting trees.
Trees, the floorboard of woody plants, are mainly composed of roots, stems, branches, leaves, flowers and fruits. With the development of computer, the tree in data structure is expanded to be composed of sets and relationships defined on sets, and is composed of root nodes and several subtrees.
Trees are perennial plants with wooden trunks and branches. General tree Screaming Trees, the main plant is one, the branches are higher from the ground, which can form a crown. There are many kinds of trees.
As the saying goes, some big shrubs are called trees, such as pomegranate trees (deciduous shrubs or small trees) and tea trees (shrubs or small trees). The National Tree of China: Ginkgo biloba.
In plants, trees and grass are different.
Extended data:
Tree rings are a layer produced by the growth of trees in a year. It appears in cross section like a wheel (or wheels) around the same wheel produced in the past. The scale ring in fish refers to the dividing line between the narrow band formed in autumn and winter and the wide band formed in spring and summer the following year. The secondary xylem produced by vascular cambium of annual rings in a growing period constitutes a growth ring. There is obvious seasonality, and only one growth ring is produced in a year, that is, the age of trees, also known as tree rings.
The role of tree rings: after the tree is sawed down, you can see an interesting phenomenon. On the cross section of the stump, there are circles of concentric circles of different colors and sizes. These concentric rings are called "annual rings". Tree rings are produced by the annual activities of the cambium. The mild climate and abundant rainfall in spring are beneficial to the growth of trees. At this time, the cambium cells divide vigorously, the newborn cells are large and obvious, and the ducts are large and many. Therefore, the wood looks light in color and soft in texture.
After entering summer, with the increase of temperature and the decrease of rainfall; Especially in autumn, the weather turns cool, the rainfall is less, the cambium activity is weakened, the cell shape is small, the cell wall is thick, and there are few ducts, so the wood looks dense and hard, and the color is dark. Cells and vessels in trees change from large to small once a year, and substances change from loose to dense, thus forming annual rings with different colors and textures.