Jul 15 2008
Examining the Root
Although the root is axial in construction it lacks the leaves of the shoot axis. Generally, roots develop in the soil, but they may also form in the water and in the air. Roots not only absorb water and minerals; they also provide the plants with firm anchorage in the soil. Occasionally the roots take over the function of a storehouse for nutrients.
When a seed germinates, the primary root or radicle (already present in the embryo) develops first. In a number of dicotyledonous plants the main root throws out subsidiary roots; these branch, become fibrous and eventually form the whole root system. Other dicotyledonous plants develop additional, adventitious roots in the axis of the shoot. Most aquarium plants belong to the latter category. The primary root often dies at a later stage. Monocotyledons always have a short-lived primary root which is replaced by adventitious roots. Ferns have adventitious roots only. Continue Reading »