Page 101 - Science Class 06

nant central root, from which other small-
sized lateral roots emanate horizontally.
Advantages of a tap root include the fact
that they do penetrate deep into the soil
and so they can locate water and minerals
deep underground, the mesquite plant for
instance has roots that can penetrate up to
150 . deep in search of water. It is thus
very drought-tolerant.
The tap root is also good at anchoring the
plant into the soil so preven ng them from
being blown over in windy environments.
Taproot
The Fibrous Root System
In grasses and other monocots including
lilies and palm plants, the root system is a
fibrous root system consis ng of a dense
mass of slender, adven ous roots that
arise from the stem. A fibrous root system
has no single large taproot because the
embryonic root dies back when the plant is
s ll young. The roots grow downward and
outward from the stem, branching
repeatedly to form a mass of fine roots.
Fibrous Root
Science-6
MODIFICATION OF ROOTS
The roots of some plants have modified
themselves in shape, size, structure and
func on to adapt to the prevailing
condi ons.
Some of these modifica ons are:
Storage Roots
These consist of thickened roots due to the
accumula on of high-energy storage
compounds, usually starch. These are
further subclassified into fleshy and
tuberous roots. Examples of crops with
fleshy roots are the carrot, ginseng (Panax),
and sugar beet while those with tuberous
roots are the sweet potato, cassava and
yam bean.
Carrot Radish Turnip
Suppor ng Roots
Some plants having fibrous roots also
develop addi onal roots from the lower
stem. These give plants an addi onal
support. The addi onal roots grow down-
ward and give firm support to the plants.
These kinds of modified roots are called s lt
roots. Maize, sugarcane, etc. are the
examples of such kind of root.
Roots also grow from the branches of the
stems of banyan trees. With the passage of
me these roots touch the ground.
Gradually, they penetrate the soil. These
roots are called prop roots.
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