My country has rich shrub species resources, with more than 6,000 species.
1. It should be judged by the structure of the tree and the growth characteristics of the branches. However, some seedlings can also be used for multiple purposes, such as osmanthus. The large ones with trunks of more than two to three meters can obviously be called trees, but some small osmanthus can only be used as hedges, such as Buddha's crown beads, which should be considered shrubs.
2. Generally, those below 3 meters can be called shrubs, but there is no obvious boundary in reality.
3. Trees: The tree body is tall (usually 6 meters to tens of meters) with obvious tall trunks. It can also be divided into four levels according to its height: Wei Qiao (more than 31 meters), Da Qiao (21-30 meters), Zhong Qiao (11-20 meters), Xiao Qiao (6-10 meters). Shrubs are short (usually less than 6 meters) and have low trunks.
It can also be seen from here that some trees are not absolute. Like the osmanthus mentioned above, they may be small trees or shrubs.
4. Classification by the shape of plant stems
Trees: Woody plants with an upright trunk and a height of more than 5 meters are called trees. In contrast to low shrubs, the tall trees we usually see are all trees, such as kapok, pine, magnolia, birch, etc. Trees are divided into deciduous trees and evergreen trees according to whether they shed leaves in winter or dry season.
Shrubs: Wood with an unclear trunk and often multiple branches at the base.
These plants are called shrubs, such as roses, dragon boat flowers, azaleas, and peonies.