The non-green underground part of the plant body is known as the root system. It develops from the radicle of the embryo. The root system is divided into three types;
- Tap root system
- Fibrous root system
- Adventitious root system
Tap root system: The tap root system is the characteristic feature of the dicot plants. Tap root system is constituted by the primary root and the secondary roots. The direct elongation of the radicle of the embryo forms the primary root of the tap root system. From the primary root there arise many lateral branches known as the secondary roots or lateral roots. The primary root or the tap root is the main root of the tap root system. The tap root fixes the plant to the soil. Examples are Pea, Mango, Carrot, Beet root etc.
Fibrous root system: The fibrous root system is the characteristic feature of the monocot plants. The radicle is short lived and so the root arises from the base of the stem. These roots are thread like in nature and almost equal length. The fibrous root system does not grow deeply in to the soil instead present on the uppers strata of the soil. Examples are Maize, wheat, paddy, Coconut etc.
Adventitious root system: The adventitious root system arises from any of the parts of the plant body other than the radicle. The adventitious root and its branches together form the adventitious root system. Examples are Pandanus, Banyan, Bamboo, grasses.