Angiosperms show such a large diversity in external structure or morphology. Angiosperms, also called flowering plants, have seeds that are enclosed within an ovary (fruit), while gymnosperms have no flowers or fruits, and have unenclosed or “naked” seeds on the surface of scales or leaves. Gymnosperm seeds are often configured as cones.
Angiosperms are characterised by presence of roots, stems, leaves, flowers and fruits. Earlier chapters have discussed about classification of plants based on morphological and other characteristics.
For further classification and understanding any higher plant we need to know about the possible variations in different parts, found as adaptations of the plants to their environment, e.g., adaptions to various habitats, for protection, climbing, storage, etc.
For example consider any plant,it may be bearing flowers and fruits. The underground part of the flowering plant is the root system while the portion above the ground forms the shoot system.