Types and systems of roots
The root is a vegetative organ of higher plants. It anchors the plant in the soil and absorbs water and dissolved mineral salts, passing them to the stem and leaves. Unlike a shoot, a root bears no leaves. By origin there are three kinds of roots: the main root grows from the embryonic root in the seed; lateral roots branch from the main or adventitious roots; adventitious roots form on a stem or leaf. All the roots of one plant make up its root system. In a taproot system the main root is well developed and bears lateral roots; this is typical of most dicots (cotton, chickpea, bean, dog rose). In a fibrous system the main root does not develop and many thin adventitious roots grow from the base of the stem; this is typical of monocots (wheat, barley, maize).
| Feature | Taproot | Fibrous root |
|---|---|---|
| Main root | well developed, bears lateral roots | does not develop |
| Roots | one thick main root | many thin adventitious roots from the stem base |
| Typical of | dicots | monocots |
Experiment: germinate bean and wheat seeds on wet cotton wool in a clear container. After 7–10 days compare and draw the root systems (bean — taproot, wheat — fibrous). Safety: handle the container with teacher permission, do not touch mould if it appears, wash hands afterwards.