The bulb is an underground shoot with leaves closely attached to the bottom. The structure of the bulb in different plants is the same, but may differ in shape and size. In their structure, all bulbs are similar to the usual onions.
General structure
Looking at the structure of the bulb on the cut, it is clear that there is a bottom at the very bottom. Below it are the roots, and above - modified shoots. They accumulate nutrients for the dormant period.
Modified shoots include not only bulbs, but also rhizomes and tubers. Plants with rhizomes are irises, wheatgrass, nettles. There are few tuberous plants, one of the most famous is the potato. It has shoots underground, on the upper parts of which tubers grow. They have shortened internodes and do not contain chlorophyll. However, when the tubers are exposed and exposed to direct sunlight for a short time, the tubers may turn green.
Looking at the structure of the bulb, you can see the embryos of the leaves. They accumulate a large amount of nutrients. They allow the leaves to start growing at any time of the year. Therefore, it is bulbous plants that are used for early forcing, planting them in winter. It's theirsdifferent from other plants. Another difference is that the number of leaves is precisely determined in bulbous plants, that is, the number of primordia is equal to the number of leaves.
In the lower part of the bulbs, near the bottom, flower buds are located. How many buds are planted, so many flower shoots will grow.
When caring for bulbous plants, you should carefully cut off damaged and dried leaves, because if the buds are damaged, the leaf dies, and if the damage is severe, the entire bulb may die.
In different plants, bulb scales adjoin each other in different ways. In lilies, they are located loosely together, but there are plants with a tight fit, such as hyacinths.
Types of bulbs
The internal, as well as the external structure of the bulb, is different for different types of plants. They are divided into the following subspecies:
- Film. Scales can cover the entire interior. The scaly edges touch. There are plants whose scales can grow together.
- Semi-tunic. There are scales that never grow together.
- Tiled. The scales are very narrow. From one edge they are in contact with neighboring scales.
- The number of scales in different plants is different. Some may have one, others three, five or more.
All scales are divided into:
- leaf;
- grassroots.
From the bottom, the scales grow, they make reserves of nutrients.
Structure of tubers
The internal structure of the tuber and bulb is different. On the outside of the tuberssprouts are located - they are called eyes. There are more of them on the top than on the bottom. When planting in the ground, the aerial part grows from the eyes.
On the underside of the tubers have stolons. They provide nutrients. They accumulate in the shoots, then there is an active growth and thickening of the shoots, and by autumn tubers grow on the stolons.
The structure of the bulb and tuber is similar only in that they accumulate substances useful to the plant. Otherwise they are different.
Rhizome structure
Rhizome is also an underground shoot of a modified type, which develops in perennials, shrubs. In it, as in the bulb, the nutrients necessary for the plant for normal development and maintenance of life are stored.
The external structure of the rhizome of the bulb resembles an ordinary root, but differs in dissected internodes and scaly leaves, on which axillary buds are formed. When the aerial part dies off, a scar remains on the rhizome.
There are simple, thin, horizontal, thick, branched, vertical and ascending rhizomes. These are not all rhizome options.
The lifespan of a rhizome is an average of five years. In some plants, it can live for two years, and in some - more than ten years.
Conclusion
Rhizome, tuber and bulb of plants are different types of modified shoots. They are similar in that they have short internodes, accumulate a large supplytrace elements and other nutrients. These plant organs do not contain chlorophyll.
Underground shoots are pantries of vital substances. They contain starch, mineral elements, phytoncides. These plant parts can be used as food by humans and also used as animal feed.
