Primarily, there are two types of root systems found in plants, namely the tap root system, and the fibrous root system. The main function of the roots is to absorb water and minerals from the soil. However, roots are also modified to perform various other functions. The roots of some plants act as storage sites for food, some provide support to massive plant structures, while others absorb oxygen from the atmosphere.
Roots and their modifications in various plants:
(a) Banyan tree : The banyan tree (Ficus benghalensis) has massive pillar-like adventitious roots arising from the aerial part of the stem. These roots grow towards the ground and provide support to the tree. Such, roots are called as prop roots.
(b) Turnip : The roots of turnip (Brassica rape) help in the storage of food. Similar food-storing roots are found in radishes, carrots and sweet potatoes.
(c) Mangrove tree : The roots of mangrove plants grow vertically upwards from the soil for the absorption of oxygen from the atmosphere as the soil is poorly aerated. These types of roots are called pneumatophores.