Morphological Structure of a Plant

Topic Description

MORPHOLOGICAL STRUCTURE OF A PLANT

Different parts of a plant perform different functions. There are two main parts of a plant- the root
system and the shoot system. The root system stays under the ground. The shoot system stays
above the ground and bears stem, leaves, flowers and fruits.

ROOT SYSTEM:
The part of the plant that is generally present under the soil is called the root. It is the non-green
part of the plant. It normally remains underground and fixes the plant in the soil. Plant roots are
mainly of two types- TAP ROOTS & FIBROUS ROOTS
Tap Roots- When the radical grows into a thick primary root vertically downward and gives off
small lateral roots, it is known as tap root. This primary root may have small roots known as lateral
roots. Carrots, radish are the examples of tap roots.
Fibrous Roots- In fibrous roots, the radical is short-lived and many roots arise as a tuft from the
base of the stem. Such roots are known as fibrous roots. Plants such as grass, maize, wheat have
fibrous roots.

Functions of Roots

a. Anchorage
b. Absorption

Modifications of Roots:
a. Food Storage- Plants store food for unfavorable conditions, so that the plant uses this food
when required. In such cases, the food prepared in leaves travel down and gets stored in
roots.
Example-carrots.
b. Extra support- To support weak stems or heavy branches, roots act as pillar in some plants
and provide extra support.
Example- Prop roots in Banyan tree.

SHOOT SYSTEM:
The stem is the main part of the shoot system. It is usually located above the ground and bears the
branches, leaves, buds, flowers and fruits.
The stem is normally divided into two parts- NODES & INTER-NODES

Node- A point on the stem where a leaf, branch, bud arises is called a node.
Inter-node- The portion of stem between two nodes is called an inter-node.

Functions of Stems

a. Holds the plant upright.
b. Conduction

Modifications of Stems:
a. Support- In some plants, such as grapevine, stems have a thread-like structure present on
them called stem tendrils which provide extra support.
b. Storage: Stems like ginger, are modified to store food. Such stems grow underground and
serve as a source of food for the plant in unfavorable conditions.
c. Making Food- Plants like cactus, have stems that are modified to take over the function of
making food. The stems in such plants are green and fleshy.