Angiosperms (Gr. Angeion: case; spermos: seeds) are a group of plants characterised by production of flowers and formation of seed(s) within a fruit. The plant body is highly complex showing a great range in size and diversity in form. This led to the morphologic and physiologic differentiation between various parts of plant body, which gave rise to a plant organ concept. The plant body is the sporophyte which is made up of several fundamental parts or organs.
The morphologists divide the plant body into three basic organs- the root, stem and leaf. The main axis of the plant body consists of a root, normally developing under the ground, and a stem normally growing up. The root bears a number of lateral structures similar to it and forms the root system. The stem holds lateral appendages in the form of leaf and branch.
The stem along with leaf is called the shoot and forms the shoot system. The root system and the shoot system together constitute the vegetative body of the angiosperm. As the plant grows and reaches maturity, it forms flowers, fruits and seeds. These three constitute the reproductive system of the plant as the flower forms the fruit and seed after fertilisation. The seed when germinates, gives rise to new plant and serves the function of multiplication of the plant.