Dicot Seeds

As said earlier there are over two lakh plant species on this planet. Some plants develop from the seed of angiosperms and gymnosperms. All plants do not produce seeds. The plant kingdom can be classified into algae, mosses, ferns, and flowering plants. This article focuses on types of seeds, especially dicot seeds, in which type of plants it is produced, etc. 

Types of flowering plants

There are different types of plants. Some plants reproduce sexually and some other plants reproduce asexually. The plants which reproduce sexually are of two different categories. The two different types of flowering plants are the Angiosperms and the Gymnosperms. In these two kinds of flowering plants, the reproductive structures are different.

Angiosperms- The term ‘Angios’ means a case that is the seed-bearing fruit and the term ‘sperm’ means seeds. Angiosperms are those flowering plants that bear the fruit, the flower, and the seed. The reproductive structures in angiosperms are unisexual or bisexual flowers. In this kind of plant, the seed is enclosed inside its fruit. This seed develops in the female part or ovary of the flower. Dicot seeds develop in angiosperms. A good example of angiosperms would be cashew nuts.

Gymnosperms- The term ‘Gymno’ means naked and the term ‘Sperm’ means seed. Gymnosperms are those plants that do not bear any fruit and are just seeds. In this kind of plant, the seeds are naked and have a thin structure. These types of plants do not bear any flowers or fruits. The reproductive structures in these plants are unisexual cones. Pine spruce can serve as excellent examples of gymnosperms.

Definition of cotyledon 

The cotyledon is situated in the embryo situated inside the seed. The cotyledon is also termed the “embryonic leaf’ in plants that bear seeds. These cotyledons appear from the germinating seeds. To become thick and swollen and to store food are the two main functions of cotyledons. Depending on this cotyledon the seeds produced in angiosperms are categorised into two types: The dicot seeds or dicotyledons and monocot seeds or monocotyledons. 

Structure of dicotyledonous seed

To understand the structure of dicot seeds, we need to first understand the meaning of dicot seeds. The seeds which have two “embryonic leaves” are called dicot seeds or dicotyledons. The embryo in which the dicot seed consists of two cotyledons and one embryo axis. The lower part of the seed that forms the root tip of the seed is called the radicle. The upper part of the seed which forms the shoot tip is called the plumule. This whole structure is covered by a layer which is called the seed coat. The outer layer of this seed coat is made up of a substance which is called Testa and the inner layer of a substance called the Tegmen. A thin layer of tissue connects the seed to the fruit and this thin layer is called Hilum. 

Plants that bear dicotyledonous seeds are known as dicotyledons. Some examples of such plants are peas, beans, tomatoes, peanuts, lettuce, oak; etc.These might also be taken as dicotyledonous albuminous seeds examples.

Structure of monocotyledonous seeds

Monocotyledonous seeds or monocot seeds are different from dicot seeds in that monocot seeds have only one cotyledon or “embryonic leaf”, whereas dicot seeds have two of those. This one quite large cotyledon is called a scutellum. This scutellum is situated in a position that is lateral to the side of the embryo axis.  Just like a dicot seed, the embryo axis of a monocotyledonous seed contains a tip representing the fully grown plant’s shoot, also known as a plumule. This plumule is surrounded by a layer known as the coleoptile. 

The tip representing a root is known as a radicle, which is covered by a layer called the coleorhiza. A layer called the aleurone layer surrounds the endosperm- the part responsible for providing a germinating seed with food. This endosperm in the case of monocot seeds is quite swollen and prominent, these seeds are also called albuminous seeds. Monocot seeds are also known to have two seed coats- an outer coat and an inner coat, within which lies the embryo of the plant.

Plants that contain monocot seeds are called monocotyledons. Some examples of such plants are wheat, maize, corn, bajra, sorghum, coconuts, etc.

Conclusion

It is truly wonderful to think that even something as small as a seed can turn into a big plant. As we delve deeper into the workings of a seed, we may know more, but the sense of wonder we have towards this thing also increases. Seeds themselves have had a great part in the advancement of human civilization, as the advent of agriculture came with the discovery of seeds. It is therefore important to study seeds, as it will help us in discovering new ways and techniques in agriculture. In this article, we learned about dicot seeds, monocot seeds, their respective structures, as well as the types of plants these seeds come from.