The plant root system constitutes the major part of the plant body, both in terms of function and bulk.
In terrestrial plants, the root system is the subterranean or underground part of the plant body while the shoot is the aboveground part.
Roots are branching organs that grow downward into the soil, a manifestation of geotropism.
Branching occurs irregularly and not from nodes as in stems.
In contrast, to shoot, the plant root has no leaves, nodes, internodes, and buds. With rare exceptions, roots also lack stomata.
Other morphological and anatomical features which are distinct to the root are:
(1) a hard, protective root cap at the tip of the root;
(2) absence of the pith;
(3) presence of endodermis;
and (4) the presence of a pericycle next to the endodermis.