Stem: similar to the function of water pipe, it can transport water and minerals absorbed by roots from bottom to top, and can also transport nutrients made by leaves from top to bottom; Leaves that support plants.

Leaves: photosynthesis, respiration and transpiration. Photosynthesis means that chloroplasts in leaves synthesize water and carbon dioxide into oxygen and nutrients through sunlight, usually in the presence of light. We usually see that the front of leaves is greener than the back because there are more chloroplasts in the front. Breathing is just the opposite. It is to react nutrients (usually starch) with oxygen, similar to human breath, and expel carbon dioxide, water and energy needed for plant growth. Breathing will take place at any time. Stomata are generally on the back of leaves, and each stomata consists of two stomatal cells. Transpiration is to send water through leaves. On the one hand, it provides power for roots to absorb water, on the other hand, it can cool plants and prevent them from dying in the sun.

Flowers: The reproductive organs of plants, which are divided into complete flowers and incomplete flowers. A perfect flower refers to a flower that contains sepals, petals, stamens and pistils, while an incomplete flower lacks one or several of them. But no matter what kind of flower, it usually bears fruit after pollination, that is, fertilization.

Fruit: For plants, fruit can protect seeds and help them spread. For example, when a bird eats the fruit from a tree, it is said that the whole fruit is swallowed. Generally, seeds are not digested, but scattered in another place with bird droppings, thus achieving the purpose of spreading seeds.

Classification of plant characteristics

1. Woody plants: The main feature is branches with xylem.

(1) Trees: Woody plants have obvious trunks.

①? Evergreen tree: it doesn't shed leaves all year round, that is, the old leaves will fall off one after another after the new leaves appear.

A. Evergreen broad-leaved trees: such as Cinnamomum camphora and Magnolia grandiflora.

B. Evergreen conifers: such as pine, cypress and spruce.

②? Deciduous trees: Deciduous leaves fall in winter. Rumeiliu

(2) Shrub: There is no obvious trunk, or although there is a short trunk, the branches are low and overgrown with weeds.

①? Evergreen shrubs: such as peach-leaf coral, summer rhododendron, etc.

② Deciduous shrubs: such as Chinese rose and Chimonanthus praecox.

Some woody plants, such as Osmanthus fragrans and Flos Magnoliae, can be in the form of small trees or large shrubs according to the climate and cultivation methods of the place of origin.

(3) Woody vines: Wisteria, Lingxiao and other plants that climb around stems or other organs are woody, although they are vines. Include evergreen and deciduous plants.

2.？ Herb: The stem has no xylem.

(1) Annual and biennial herbs: including all herbs whose life cycle does not exceed the 2nd anniversary, and herbs whose life cycle is within the 2nd anniversary in actual cultivation. The former is like cockscomb and impatiens, while the latter is like daisy and snapdragon.

(? 2) Perennial herbs: those with a life cycle of more than 3 years.

(1) Perennial plants: plants that overwinter with roots or wither on the ground in winter and sprout new branches in the following spring, such as chrysanthemums and peonies.

(2) Bulb plants: Rhizomes, underground stems or rhizomes are shortened into spheres, blocks or other irregular thick strips.

a.？ Bulb: Actually, it is a complete plant with stems, leaves and flowers, which are tightly embedded, spherical and dormant. Grow and blossom when the environment is suitable. Bulbs have scales, such as tulips, daffodils and clivia, and those without membranes are like lilies.

B bulb: a very short, swollen, spherical or oblate rhizome or stem base without fleshy scales, such as gladiolus and vanilla.

C. Tubers: underground stems are thick and have sprouting points on them, such as begonia, cauliflower, cyclamen, Erythrina grandiflora and THE TEMPLE OF JIALAN.

D. tuberous roots: the roots are hypertrophy, such as dahlias and mirabilis jalapa.

E. Rhizome: It is a kind of underground stem, stout, can take root at the top, and also has obvious buds, such as canna, lotus, Hosta, iris, calla lily, bracken and so on.