Structure of an Angiospermic plant

An angiosperm is a flowering plant with an ovary in which the ovules are borne on a single carpel or a group of carpels that resemble a single structure. This type of plant has pollen present on the stamens. The seed is produced after pollination and typically consists of three parts: an embryo, endosperm and cellulose. 

Fossil records indicate that angiosperms have existed for at least 125 million years. The oldest fossils of angiosperms, such as pollen and spores from the late Devonian time, suggest that it may have evolved from cambial initials (the hypothetical first plant cell).

Angiosperm plant

Angiosperm name is derived from the Greek word “angio”, which means a vessel, and “Sperma”, meaning seed.

The embryo is formed after pollination in angiosperms and is typically contained inside a seed. There are three parts to a seed (embryo, endosperm, and cellulose), and they are usually held together by two integuments: the outer integument (tegmen) protects the seed from physical damage and is fleshy; whereas the inner integument (testa) surrounds the tegmen and absorbs water for optimal water absorbency.

The angiosperms are the most diverse of all vascular plants. More than 2,90,000 species in over 130 families outnumber all other plant groups.

The monocotyledons and eudicotyledons have very different internal structures, but they do possess some common features and some unique ones. Both are vascular plants and contain chloroplasts, although they have differing numbers per cell.

Structure of an Angiospermic plant: Vascular system 

The vascular system is the primary transport system in the plant. Like animals, the vascular system transports fluids and nutrients throughout the plant. In flowering plants, the primary vascular tissue consists of the xylem and phloem. Xylem is rigid water-conducting tubes that carry water and mineral nutrients from a root to other plant parts, such as leaves, stems, flowers and fruits. The presence of pores and vessels in the secondary xylem is a major feature differentiating angiosperms from other vascular plants. These vessels are important in providing the transport systems that enable their growth.

Structure of an Angiospermic plant: Ovary 

The ovary is a chamber formed from the ovule where one or more carpels are formed. The term “ovary” comes from the Latin word “ovum”, meaning “egg”. In angiosperms, the ovary is composed of one or more chambers, each containing one or more carpels. The primary internal part of an angiosperm flower is the ovary. Its simplest form consists of a thin layer of tissue with a single empty chamber that surrounds and protects the developing ovule.

The ovary is sometimes called the “fruit”, surrounding and protecting the developing fruit. In many flowering plants, the outer wall of the ovary grows towards the centre, causing the ovary to be composed of multiple chambers (called locules), each separated with a partition wall. 

However, in several families of flowering plants, including Fabaceae (soybeans and peanuts) and Lamiaceae (mints), the carpels fuse in various ways to form a single chamber inside the ovary.Depending on the ovary type, the ovary may or may not contain the ovule. The term “ovary” comes from the Latin word “ovum”, which means “egg”.

Structure of an angiosperm plant: Ovule 

The ovule (or archegos) is an undeveloped seed within an angiosperm ovary. In angiosperms, it is formed from the egg-shaped nucellus (the remnant of the primary cell mass that develops into a seed during fertilisation).

The cotyledons are important in maintaining plant metabolism and growth during seed maturation.

Structure of an Angiospermic plant: Flower 

The inner stamens and/or petals are part of the flower. There are four basic types in angiosperms: perfect, superior, inferior, and lateral stamens. These different types of stamens come in various shapes and sizes.

In flowers with more than one petal (triangular or showy), the number of these organs is determined by the number of carpels that form the ovary.

Structure of an Angiospermic plant: Fruit

The pericarp is composed of the integument or coat covering the entire fruit. It is often fleshy and is usually divided into three layers: the exocarp, mesocarp and endocarp.The endocarp of a specific fruit wall consists of the cotyledons and, in some plants, a single seed. It remains solid until maturity.The exocarp is composed of the pericarp plus Examples are avocado, tomato, and chilli pepper.The mesocarp is composed of one or more seeds.

Examples of the structure of Angiospermic plant

The banana plant’s anatomically oblong, five-parted fruit consists of the (often fleshy) outer skin layer or pericarp (fruit layer), a central cavity or xylem, and a fleshy endocarp.Strawberry is one type of berry produced by plants belonging to the family Rosaceae, including many named genera and species.

Conclusion

Certain characteristics of angiosperms have made them highly adaptable to life on land, where they present a major challenge to evolution. These are better known as the characters of the plant. The angiosperms are the most diverse of all vascular plants. With more than 2,90,000 species, they outnumber all other plant groups. In addition to this huge diversity and the general flexibility of their morphology, the angiosperms have also evolved several highly specialised features. These features have allowed them to occupy nearly every niche. Strawberry, banana, and mint are some examples of the structure of an angiospermic plant.