Introduction:
The existence of nodes and internodes in plant stems, whether above or below ground, distinguishes them (Figure 23.4). Leaves, aerial roots, and flowers link to each other at nodes. An internode is the section of the stem between two nodes. The petiole is the stalk that connects the stem to the leaf base. An axillary bud can give rise to a branch or a flower in the axil—the space between the base of a leaf and the stem. The apical meristem in the apical bud is located at the apex (tip) of the shoot.
Characteristics of Plant Stem:
A plant’s shoot system includes stems. They can be a few millimetres long up to hundreds of metres long. Depending on the plant kind, they also vary in diameter. Although certain plants, such as the potato, have underground stems, the majority of their stems are above ground. Herbaceous (soft) or woody stems are both possible.
Stems serve as a support system for the plant, holding leaves, flowers, and buds in place; in rare situations, stems also serve as food storage. A palm tree’s stem is unbranched, while a magnolia tree’s stem is heavily branched. The plant’s stem connects the roots to the leaves, allowing absorbed water and minerals to be transported to various sections of the plant. The stem also aids in the movement of photosynthetic products (sugars) from the leaves to the remainder of the plant.
Nodes and Internodes in a Stem:
The existence of nodes and internodes in plant stems, whether above or below ground, distinguishes them. Leaves, aerial roots, and flowers link to each other at nodes. An internode is the section of the stem between two nodes. The petiole is the stalk that connects the stem to the leaf base. An axillary bud can give rise to a branch or a flower in the axil (the space between the base of a leaf and the stem). The apical meristem in the apical bud is located at the apex (tip) of the shoot.
The survival of plants depends on the stems. The primary body of a plant is made up of stems, which are long, stalk-like structures. Although some stems can be found beneath, they usually emerge above ground. The stem provides support for the plant and allows it to move to gain access to light and supply critical nutrients to the various plant parts.
Some plants, like the North American Hyperion tree, can have stems reaching up to 115 metres (about 380 feet) in height, stems must be well adapted for these functions
Tissues in Plants Stem:
Dermal tissue, ground tissue, and vascular tissue are the most common tissues found in stems. The dermal tissue protects, waterproofs, and regulates gas exchange on the stem’s exterior surface. The ground tissue fills in around the vascular tissue and is usually made up mostly of parenchyma cells. It helps in photosynthesis on occasion. Long-distance transport and structural support are both provided by vascular tissue. Woody stems may lose most or all of their ground tissue. Waterproofing may not be present in the dermal tissue of aquatic plant stems. Plant species differ greatly in their circulatory tissue organisation.
Conclusion:
Therefore in this unit, we studied stem, their characteristics and their function in the living plant body. . Stems serve as a support system for the plant, holding leaves, flowers, and buds in place; in rare situations, stems also serve as food storage. A palm tree’s stem is unbranched, while a magnolia tree’s stem is heavily branched. The plant’s stem connects the roots to the leaves, allowing absorbed water and minerals to be transported to various sections of the plant. It also aids in the movement of photosynthetic products, such as sugars, from leaves to the remainder of the plant.