Describing the morphological structure of a plant’s bud is quite simple. A plant bud consists of a rudimentary stem, leaves, and flowers. Plant buds are classified into two types: growth (vegetative) and flower (generative). The vegetative bud of a plant consists of leaves. The generative structure includes the beginnings of flowers and inflorescences. A bud is a generative bud that has one flower. The buds, which are simultaneously represented by the rudiments of leaves and flowers, are called vegetative-generative, that is, mixed.
On the growth cone , rudiments of leaves are formed, which are located from the bottom up. Due to the fact that they grow unevenly, they tuck up to the top, which causes the appearance of a moist space inside the kidney. Thus, the bud of the plant protects itself from drying out and damage. In the process of bud blooming, the leaves move away from the stem and straighten, which is primarily due to the active growth of the internodes of the stem.
As a rule, the bud of a plant is brown, gray or brown. The buds of some woody plants, especially those that grow in cold climates, are covered with scales (modified leaves) that protect them from cold and damage. Some trees (for example, birch, poplar) secrete resinous substances that improve this protection. Such a plant kidney is called closed or protected. Accordingly, plant buds that do not have scales are called unprotected or bare. The thick fluff that covers these organs from the outside is an additional means of protecting them from a variety of adverse factors.
Some herbaceous plants (wheatgrass, lily of the valley) have wintering buds that are located on underground shoots, they can also be found in the lower part of aboveground shoots near the ground. Thanks to just such a placement, the bud of the plant copes with temperature fluctuations quite easily. Some types of plants (for example, cacti) have individual structural features of this organ. Cactus buds are called areoles, they consist of modified scales - needles, which perform a protective function.
Given the location of the kidneys on the stem, they are divided into lateral and apical. The bud at the end of the shoot is called terminal (apical), thanks to it, the stem grows. Side kidneys form a system of shoots. The lateral bud of a plant is called axillary, if it is localized in the axils of the leaves. Extra-axillary (accessory or additional) buds are those that are laid in different parts of the stem, including on the roots.
The buds in the axils of the leaves can be placed both individually and in groups. It should be noted that the localization of the kidneys in the axils of the leaves is of great biological importance. The covering sheet protects the kidney from mechanical damage, it also takes an active part in providing the kidney with nutrients.
With the help of the accessory buds, vegetative propagation is carried out . Thus, root-sprouting plants (sow thistle, aspen) multiply. What are root offspring? Simply put, these are shoots that develop from the accessory buds on the roots. Extra-axillary buds on the leaves of plants develop very rarely. An example is Kalanchoe. Its buds immediately produce shoots of small sizes with subordinate roots.
Most perennial plants, shrubs, and trees are characterized by dormant buds, which can remain unopened for a long period of time. They may not transform into shoots for years, but there are factors that contribute to the development of sleeping kidneys (for example, the death of the main trunk). Sleeping kidneys play a key role in the life of shrubs. Thanks to their development, daughter trunks are formed, the sizes of which can be several times the diameter of the mother trunk. Now you know what the kidney of a plant is and what functions it performs.