We are used to naming the main parts of plants. One of them is the leaf stem. However, many people do not know what is stem. It must be taken into account that the science that studies plants is botany and it contains scientific concepts about the parts of a plant.
For this reason, we will devote this article to telling you what the leaf stalk is called in botany and what functions it has.
Contents
What are the stems of plants called?
The stem is the main aerial part of the plant and is responsible for giving the plant structure and supporting its various organs such as leaves, flowers and fruits. Therefore, its two main functions are the supply of support and the transport of nutrients and substances between the roots and the leaves, the first as a result of the feeding process and the second as a result of photosynthesis.
The stems exhibit negative geotropism, which means that they grow in the opposite direction of gravity. They also have nodes from which leaves arise, and they have different types of internodes and buds. Additionally, in some types of plants, stems may have specialized functions, such as the storage of nutrients in the tubers or the presence of tendrils in certain climbing plants.
Stems can be categorized by:
- clandestinely
- air
- aquatic
rod types
Below, we explain each of these types and discuss their subtypes in detail with examples. In addition, we will talk about the types of edible stems, mainly underground and aerial.
underground stems
Underground stems are those that, as their name suggests, grow underground. They have shoots from which branches, leaves and adventitious roots can grow. There are several types of underground stems as they can be subdivided into:
- Tubers: They are short and thick and have the peculiarity of storing reserve substances and nutrients. They have slits, commonly called eyes, which produce aerial stems. Some examples of tubers are potatoes, cassava, maca and Jerusalem artichoke.
- Rhizomes : Thick underground stems that grow parallel to the ground surface. They develop protective scales, and when the warmer months arrive, their shoots will sprout. Examples of rhizomes are lily, ginger, grass and bamboo.
- Bulbs: They form a short-stemmed capsule with roots at the base and buds at the top, surrounded by several layers of specialized leaves that serve as a reservoir for storage substances. During the warmer months the stem grows outdoors, while during the colder months the bulb survives underground. Onions and tulips are bulbs.
aerial stems
Aerial stems are stems that grow and develop above the ground. They are divided into several types of aerial stems:
- right: They grow completely upright and do not require additional support.
- lianas: They are not rigid, so they grow horizontally. Examples of runners are pumpkins and carrots.
- Climbers: They use other plants or external objects as support. An example is paper flowers or helichrysum and bougainvillea.
- inconstant: Stems with little resistance, spiraling around support stems, can be another plant or any mentor. An example is a bell.
There are other special types of aerial stems which are:
- Large trees and shrubs grow a trunk, a very branched and resistant stem.
- The stems of some plants are called sugar canes. They are cylindrical and have distinct knots. An example of this is wheat.
- Like strawberries, some runners can grow into the ground and produce roots to produce new plants. These are called stolons.
- Some climbing plants, such as lianas, have special stems which are fine spirals whose function is to allow the plant sticks to the supports it has within its reach. These are tendrils.
- Some stems, like those of roses, bear thorns to defend themselves against predators.
aquatic rods
Aquatic stems grow in flooded or muddy areas, that is, in land with many puddles. They can be seen in underwater plants and plants floating in water. Here are some examples of types of aquatic rods:
- water hyacinth
- Water lilies, like water lilies
- water lettuce
edible stems
To finalize this list of rod types, we would like to point out that another way to classify them is based on whether they are edible or not. In fact, there are many varieties of edible stems commonly used in different cuisines around the world.
From the most obvious, such as asparagus, radish, beet or celery, to others less known in the West, such as bamboo or fern. The latter are usually eaten lightly boiled, while bamboo shoots have been eaten in Asia since ancient civilizations, cooked, pickled or preserved. Also, not everyone knows that cinnamon, which is used as a spice, is also eaten for its stems.
Another plant traditionally consumed as food and with medicinal properties is fennel, consumed in many ways and essential in Provençal cuisine. Finally, other examples are sugar cane, shallots, rhubarb and beets, not only for its leaves, but also for its white stems, called penca.
Different components
- Tie: point of attachment of leaves, aerial roots and flowers.
- internode: stem section between two stem nodes.
- Petiole: stem that extends from the stem to the base of the leaf.
- Axillary bud: embryonic bud found at the junction of the stem and the petiole and giving rise to a branch or a flower.
The main function of the stem is to support the leaves, to transport water and minerals to the leaves, where they can be converted into usable products by photosynthesis, and to transport these products from the leaves to the rest of the plant, including roots.
Stems are part of the shoot system of plants. Their length can vary from a few millimeters to several hundred meters. They also vary in diameter, depending on the type of plant. The stem is usually above ground, although the stems of some plants, such as potatoes, also grow underground.
I hope with this information you can learn more about plant stem.