This first root absorbs water which is needed for the seedling to develop. As the primary root elongates, secondary or side roots develop. Cells in the last region will form fragile root hairs through which most water and nutrients enter a plant. Root hairs only live a few weeks and are replaced by hairs developing on younger cells. In woody plants, as the roots mature they will grow wider, developing additional vascular tissue and a protective bark.
Most plants produce a fibrous root system , a tap root system or a fleshy root system .
Fibrous roots are fine and hairlike, forming a densely branched mass. Grasses, African violets and squash are examples of plants with fibrous roots. Tap roots form from a primary root that has few side branches and is the site of anchorage and absorption. In addition, taproots may be thick storage roots. Examples of taproots are the carrot, beet, radish, turnip and most trees.