Angiosperms are a group of flowering plants that represent a major community in the plant kingdom. Angiosperms occur in all typical habits and constitute a very useful group of plants for animals and human beings. They include about 2,50,000 species distributed all over the world. They are the most highly evolved group of plants and appeared on Earth about 130 million years ago.
Generally, the stems are aerial and grow above the soil surface. Sometimes, the stem becomes variously modified to perform special functions like perennation, vegetative propagation and food storage. The modified stems may be grouped under three heads viz, underground, subaerial and aerial.
Stem Modifications
Root is the descending portion of the axis of the plant. It is not normally green in colour. It is characterised by the absence of nodes and internodes.
Roots sometimes have special functions to perform and in such cases their form and structure differ from those of normal roots.
Root Modifications
