The first root to emerge from a seed is the radicle or primary root. In most dicots, the radicle enlarges and forms a prominent tap root. A taproot system is common in conifers and dicots. It functions as food reserves such as carbohydrate storage or for reaching water deep in the ground. Taproots usually control growth and development of branch roots.
Taproots grow longer than branch roots.
Because the adventitious roots of monocots are so extensive and cling to soil particles, such plants are excellent for preventing erosion. The adventitious roots of most monocots begin to grow soon after the seed germinates. Each node in the embryo usually produces 2-6 seminal roots that grow from the seed. These roots are soon supplemented by a system of crown roots that grow from nodes of the shoot. Recent studies of monocot systems tell us they are more complex than originally thought.