We are used to naming the main parts of plants. One of them is the stem of the leaf. However, many people do not know what is stem. Keep in mind that the science that studies plants is botany and in it there are scientific concepts about the parts of a plant.
For this reason, we are going to dedicate this article to telling you what the stem of the leaf is called in botany and what functions it has.
What are plant stems called?
The stem is the main aerial part of the plant and is responsible for giving the plant structure and supporting its different organs such as leaves, flowers and fruits. Therefore, its two main functions are the contribution of support and the transport of nutrients and substances between roots and 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 the leaves are born, and they have different types of internodes and buds. Also, 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 some climbers.
Stems can be classified by:
types of stems
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 are those that, as their name suggests, develop 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 characteristic of storing reserve substances and nutrients. They have slits, commonly called eyes, that produce aerial stems. Some examples of tubers are potatoes, cassava, maca, and Jerusalem artichoke.
- Rhizomes: Thick underground stems that grow parallel to the soil 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 reserve substances. During the warmer months, the stem grows outside, while during the cooler months, the bulb survives underground. Onions and tulips are bulbs.
Aerial stems are stems that grow and develop above the ground. They are divided into several types of aerial stems:
- upright: They grow completely upright and do not require additional support.
- creepers: They are not rigid, so they develop horizontally. Examples of runners are pumpkins and carrots.
- Climbers: They use other plants or external objects for support. An example is paper flowers or helichrysum and bougainvillea.
- fickle: Stems with little resistance, spiraling around supporting stems, can be another plant or any mentor. An example is a bell.
There are other special types of aerial stems that are:
- Large trees and shrubs grow a trunk, a highly branched and resistant stem.
- The stems of some plants are called sugar canes. They are cylindrical and have very distinct knots. An example of this is wheat.
- Like strawberries, some stolons can develop in the soil and produce roots to produce new plants. These are called stolons.
- Some climbing plants, such as lianas, have special stems that are fine spirals whose function is to allow the plant adheres to the supports that it has within its reach. These are tendrils.
- Some stems, like those of rose bushes, grow thorns as a defense against predators.
The aquatic stems develop in flooded or muddy areas, that is, in land with many puddles. They can be seen in underwater plants and plants floating in the water. Some examples of types of aquatic stems are:
- Water hyacinth
- Water lilies, like water lilies
- water lettuce
To finalize this list of types of stems, we would like to comment that another way to categorize them is based on whether they are edible or not. In fact, there are many varieties of edible stems that are commonly used in different cuisines around the world.
From the most obvious, such as asparagus, radish, beetroot or celery, to others less known in the West, such as bamboo or ferns. The latter are usually eaten lightly boiled, while bamboo shoots have been eaten in Asia since ancient civilizations, boiled, 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, which is consumed in many different ways and is key 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.
- Knot: 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 petiole and giving rise to a branch or flower.
The main function of the stem is to support the leaves, carry water and minerals to the leaves, where they can be converted into usable products through photosynthesis, and transport these products from the leaves to the rest of the plant, including the roots.
Stems are part of the shoot system of plants. Their length can vary from a few millimeters to hundreds of 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 that with this information you can learn more about the stem of plants.