Leafs are most important parts of plant as these consist of
chlorophyll which is used for making the food for plant during
photosynthesis. These leafs are on which
animals live. This chlorophyll will give green colour to plants and leafs.
Leafs are thin and are important part of food for animals.
Leafs also provide beautification to plants.
There are following parts of leaf:-
(i)
Leaf base
(ii)
Petiole
(iii)
Lamina or leaf blade
(i)
Leaf base:
- Leaf base is attached to stem of the branch. Some plants a
leaf grows from side base of leaf base. These are known as stipules.
(ii)
Petiole:-Petiole is
like stem but not of plant but of leaf. Petiole joins the blade to the stem.
Petiole has little tubes which attaches the vein on leaf blade to the stem.
These tubes provide water to the leaf. Apart from the water these also provide
the photosynthesis products from leaf to other parts of plant.
(iii)
Lamina:-This is
also known as blade and it is main part of the leaf. It is usually large and
flat. That is part of leaf where photosynthesis takes place.
There is main vein which you can
see from leaf which runs from tip of petiole to the other end of leaf blade and
is known as Midrib. From Mid-veins other veins originates. The edge of
lamina is known as the leaf margin. The cells inside lamina which are nearer to
surface of leaf contains chlorophyll which is used in photosynthesis.
The leaves which don’t have petioles and are directly
attached to plant stem are known as sessile leaves.
è Edge of the
leaf is known as margin
è The arrangement
of the veins in the leaf is called venation pattern there are two types of
venation patterns :-
(a) Monocots
and
(b) Dicots
Monocots has parallel venation
means all the veins are in straight lines across the length of leaf.
In Dicots veins of the leafs have net
like appearance.
àLeafs also helps in absorption of carbon dioxide and release of oxygen
through tiny pores present in the leaves called stomata.
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