The primary root grows vertically down into the soil in the tap root system. Later lateral or secondary roots grow from this at an acute angle outwards and downwards, and from these other branches may arise. The primary root usually dies at an early stage and is replaced by numerous roots that develop from the stem. These roots, which develop from the stem, are equal in size . They are known as a adventitious roots , which give rise to branch or lateral roots and form an adventitious root system , e.g. the mealie.
Roots absorb water and mineral salts from the soil.
Roots may store food . Roots form a passage way for water and dissolved substances from the root into the stem and also for foods from the stem down into the root. The tip of the root is covered by a cap that is shaped like a thimble. The outer cells of the root cap are continuously being worn away and new cells are added to the inner portion. As these cells disintegrate they form a strong protective cover.