Roots have the enormous task of securing the plant
in the ground--through wind and rain and snow and dark of night! Imagine the force of a
strong wind blowing through a huge tree, and you can imagine the incredible strength of
the roots keeping it upright. A hurricane may take out hundreds of trees--but think of the
thousands still standing!
Plants have adapted
different approaches to anchoring themselves. Root systems can be classified into two
types. A fibrous root system consists of
many relatively thin, highly branched, spreading roots. Familiar plants with fibrous roots
include tomatoes and grasses. A taproot
consists of one of more large main roots with smaller side roots; examples include carrots
Fibrous roots tend to be concentrated near
the surface of the soil; they anchor the plant through an extensive
network of fine roots. Some plants have particularly extensive
root systems. For example, if all the fibrous roots of a single
mature grass plant were laid end to end, they might go on for
100 miles or more! Because of this characteristic, these plants
are usually good at controlling erosion.
Plants with taproots take a different approach. Taproots
grow straight down, rather than spreading along the surface. They can grow to enormous
depths--some trees' taproots reach down thirty feet or more, anchoring the tree securely
Like stems, roots can become woody, providing strong
anchors for trees and shrubs.