Parts of an angiospermic plant can be very conveniently observed in a common annual plant like sunflower (Fig. 17) or mustard (Fig. 18).
The underground organs are the roots, by means of which the angiospermic plant remains anchored to the soil.
Moreover, the roots absorb water and mineral matters from the soil. The main root has many branches and sub-branches going in different directions in the soil to carry on the functions effectively.
The aerial portion is called the shoot. The axis continuous to the root is the stem which bears leaves at the joints called nodes. The inner angle formed between stem and leaf is called the axil of the leaf. Buds are present at the axil. Theses buds, in courses of times, develop into branches.
So the stem bears organs and conducts water absorbed by the roots from the soil to the leaves. The leaves are the organs where complex organic food matters are manufactured out of water and carbon dioxide in sunlight.
Prepared food matters are also conducted to different parts by stems and branches. After attaining maturity the plant flowers. Floral buds come out from the shoots and open out in time. Some part of the flower develops into fruit and the fruit contains seeds.
Every seed contains a multicellular baby-plant, called embryo, which remains dormant. During germination this embryo wakes up from the state of dormancy and develops into a new plant.
The plant as a living thing has to carry on the different life processes. The organs of the plant have particular functions to perform, but the life of the individual angiospermic plant becomes possible only when all the organs work harmoniously. That shows a clear division of labour in angiospermic plants. Roots, stems, leaves are the organs indispensable for the maintenance of the life of the individual plant.
So, they are called vegetative organs or organs of vegetation. But the flowers have nothing to do with the life of the plant. Even if a plant does not flower at all it will carry on its existence normally and will ultimately have natural death. But with the death of the plant its race will become extinct.
Flowers are purely meant for multiplication or perpetuation of the race. They are called reproductive organs or organs of reproduction. Fruits and seeds mainly protect and help in dispersal of the new plant lying inside the seed.