Just like any other living thing, plants need food to survive, grow, and reproduce. For this reason, good food preservation is crucial for plant growth and survival. Without this, their leaves are unable to undergo photosynthesis and they can’t produce food.
Storing food helps plants use it during winter when sunlight is very little and so they photosynthesis less frequently. For instance, carrots store food in the roots and survive with it during the winter season and grow a new plant from the root during summers.
Plants store extra food in the seeds and when the seed grows, it obtains food from the plant until the plant can undergo photosynthesis and produce its food.
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5 kinds of plants that preserve food in their stems
Our main focus here is food preserved in the stem of a plant. The stem preserves food and also connects other parts of the plant to the main plant. However, here are 5 different kinds of plants that use their stems to preserve food:
- Corms and bulbs
Typical stems are situated above the ground. Some items are located either above or below the ground. Such stems are referred to as "modified stems”. Modified stems located above the ground are crowns, stolons, or spurs. Modified stems located below the ground are bulbs, corms, rhizomes, and tubers.
The following types of plants preserve food in their stems:
Featured picture by: Ton Rulkens
Tubers are vegetables that store food in the underground stem. They are used for plant perennation, that is, the survival of winter and dry months, to provide energy and nutrients plants need for growth in the following season. Unlike corms or bulbs, tubers do not have a basal plant from which new shoots or roots grow. Tubers produce nodes or buds all over their surface, which then grow up through the soil surface as shoots and stems. In some cases, these nodes shoot down into the soil like roots.
Because these tubers are all high in nutrients, we often frow them as food (potato or yam)
Tubers exist in two forms; stem tubers and root tubers. Stem tubers include plants such as the potato and yam. Stem tubers form out of thickened rhizomes or stolons.
Root tubers, on the other hand, include plants such as potatoes, yam, taro, Jerusalem artichoke, sweet potato, and dahlia. Root tubers can be formed either at the end or middle of a root. Root tubers are perennating organs i.e. they store nutrients over periods when the plant cannot grow normally thus facilitating the survival of the plant over the next season.
Rhizomes (also known as rootstocks) are horizontal underground (or at the soil surface) stems found in mint, water lily, irises, ginger, and many kinds of grass. What makes these kinds of plants unique is that they grow perpendicular, permitting new shoots to grow up out of the ground. It's often hard to see if a plant is a rhizome or a root.
However, roots never have knots or leaves. Rhizomes always have nodes with or without leaves. If there are no leaves, the leaf scars can still be seen.
Rhizome plants can be enlarged for food preservation. Rhizomes store starch, proteins and can be used in vegetative reproduction. Some plants such as bamboo and hops grow their rhizomes above the ground and largely depend on vegetative propagation.
In water lilies and ferns, the rhizome is the only stem of the plant. Such plants only have their leaves and flowers visible. Rhizomes of plants such as ginger, turmeric, and lotus are edible and are valued for their culinary applications.
Corms and bulbs are mostly used interchangeably. Bulbs are plants that store their complete life cycle in an underground structure. The structure is designed to store nutrients to help the plant survive during periods of dormancy. Examples of such plants include; tulips, grape hyacinths, and alliums.
A corm is a swollen stem base that consists of one or more internodes with at least one growing point that is used for preserving food to the plant. When cutting in half, corms do not show storage rings, unlike bulbs. Corms also have a root system that can only survive one season. New corms are closer to the surface of the soil because they develop on top of the old corms. Examples of plants that develop corms include crocus, autumn crocus, and potato.
The difference between corms and bulbs is that with bulbs, their food is stored in the underground leaves (the fleshy skirts or scales). While with corms the food is stored either in the root or the stem.
Picture by: Fabian
A stolon is a stem that curves towards the ground and, on reaching a moist spot, takes root and forms an upright stem and eventually a separated plant. Stolons assume horizontal growth below the ground or on the soil surface. They form adventitious roots at the nodes (see picture) of the plant. They may also grow into buds. Stolons are often called runners.
Many weeds have stolon by which they propagate asexually and can multiply quickly.
Plants with stolon are called stoloniferous. Plants with stolon that growing below the surface of the soil include many kinds of grass, silverweed, Fragaria, ajuga, Mentha, and starchy. Some plants like the potato start growing stolon within 10 days of the emergence of the plant above the ground. Such plants begin to form tubers usually at the end of the stolon.
Other plants with stolon include strawberries, hydrilla, erythronium propullans, convolvulus arvensis among others.
Crown is the part of a plant at the surface that facilitates the formation of a new shoot. In other words, new shoots are formed from the crown. The crown is the part of a plant that joins the stem and the root. sometimes a crown is referred to as a plant base. On the trees, the area where branches grow from the tree trunk is the crown. Examples of plants include spider plants, African violets, asparagus spears.
Whether these plants are planted in a container or the ground, most plants are planted so that the crown is right at the soil level. Burying the crown lower than soil level can lead to crown rot and eventually the plant will die.
What is the function of crowns? Crowns perform a very crucial role in plants: transferring nutrients and energy between roots and stems. Most people plant with crowns just above the soil surface.
Spur is the short, stubby, lateral stems that form the main stem of the plant. Spurs develop on the shoots that are 2 years or older and can be branched or unbranched. Did you know that both flowers and fruits can form on spurs? So, they are good stores for food.
The number of spurs on an apple tree, for example, is highly connected to the overall apple yield. If the spurs are damaged or not fully grown, there might grow no fruit or flowers on these spurs. If the spurs grow long stems without fruit it can be because someone pruned the tree too close to fruit-bearing spurs.
Did you know that spurs need proper care? Yes, spurs need proper care because they are essential for plant growth. If spurs are trimmed, the shots end up producing long stems that never bear fruits. Also, spurs can die if they don't get adequate oxygen and sunlight. For this reason, pruning them is essential to prevent the dense growth of spurs. Examples of plants that grow spurs include pear, apple, and cherry.
Good food preservation is important for plants to be able to survive and grow during dry seasons. Without food, they can’t even produce food. Most stems develop from the root and support the plant by firmly holding the leaves and the flowers, carrying water, and storing food. Some roots, although, function differently and have evolved to performing life-saving functions that enable plants to survive under harsh environmental conditions. Plants that store food in the stem perform more functions that are essential for plants' survival.