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Posted By VOTRE ALARME AVEC TLSURVEILLANCE Tina Touzi on 06-11-2023 11:11:43

Description

1. The cycle of annual plants
An annual plant is characterized by a life cycle of one year.

– At the beginning of spring, when climatic conditions become favorable for seed germination, they form a small root and a young stem which become a seedling.
For seeds to germinate, sufficient humidity and a mild temperature are required. These conditions are met in spring when there is abundant rain and the days are warmer.

– At the end of spring, if conditions remain favorable, this seedling grows sufficiently to become an adult plant.
This plant produces flower buds that open and produce flowers. Flowers are the organs necessary for plant reproduction.
They have different organs such as the pistil and stamens.

– When pollen from flowers is carried on the pistil of the same flower or other flowers, these flowers produce seeds which are protected by a fruit.

– During the summer, the fruit develops and takes different shapes.

– In the fall, the entire plant withers and dies, the fruits fall, rot and thus release the seeds which are buried in the ground.

– During the winter, these seeds, very resistant to the cold, will remain in the ground until the following season. They can even remain in the ground for several years without germinating if the germination conditions are not met, because they are also very resistant to drought.

2. The cycle of perennial plants

Perennial plants do not die completely in winter. Part of the plant disappears, but some of their organs survive during the winter and develop again the following spring.

In autumn, the deciduous leaves of shrubs (example: vine) and trees (examples: chestnut tree, plane tree) fall. The aerial buds become very visible, but their scales protect them well from the cold and rain. Certain herbaceous plants (example: tulip, daffodil, iris, Solomon's seal) lose both their stems and their leaves, and only retain their underground buds.

In winter, these organs of resistance to cold and drought appear in several forms such as roots, tubers, rhizomes and bulbs, which are underground organs (they become invisible above the ground) as well as the trunks and branches, which are the aerial organs (they remain visible above the ground).

Perennial plants live for several years. All resistance organs contain nutrient reserves and buds, tiny leafy branches enclosed in scales which protect them against rain, drying out and shock.

In spring, the aerial and underground buds hatch when climatic conditions become favorable again and the sap circulates again. They generate new branches and new stems, carrying leaves, flowers or new buds.

The essential

Plants occupy the environments in a varied manner throughout the seasons.

In winter, annual plants disappear. Only their seeds survive in the soil while waiting for good germination conditions.

Perennial plants have organs that survive all winter. Some have small or glazed evergreen leaves that remain over winter. Others have deciduous leaves that fall from the branches, leaving only the buds visible during the winter. Still others have buds on their underground cold-resistant organs.

Buds and seeds develop when climatic conditions are favorable.