Leaf: Morphology, Anatomy, Modified Leaves (part 1)

• Leaves are the principal food producing organs of a plant.

• They are designed to efficiently collect light and utilize that light energy to manufacture food.

•  Different parts of a leaf:

1: Tip or apex

It is the top of the leaf. Tip can be round, smooth, pointed etc.

2. Margin

It is the border of the blade, quite specific to each species of plant • they can be smooth, toothed, lobed or incised.

3. Midrib

It is the central vein running down the middle of the blade.

4. Veins

have the xylem & phloem of the plant

·         Their arrangement can be parallel or netted

5. Base –it is present at the bottom of the blade. Just like the apex, it can be round, heart shaped, flat, etc

6. Petiole –it is also known as the leaf stem; not exactly like a stem, but it does carry xylem & phloem; carries the blade away from the stem.

7. Blade

 It is the main collecting structure of the leaf. It has a large and broad surface.

• Has many layers which aid the plant move and reserve photosynthetic materials and by-products.

Some of the Major Types of Leaves

• There are different types of leaves

• various are adapted to hot, dry climates

           • They accumulate water in their leaves or are smaller in size

• Some have very large blades to accumulate maximum light in shady locations

• Some plants have their blades broken into numerous sections.

A leaf having only one blade on its petiole is known a simple leaf.

• Maximum plants have simple leaves.

•A leaf whose blade is divided into three or more sections; it is called as compound leaf.

Pinnate leaf - leaf with the leaflets on each side of a common axis. A leaf similar to a feather, is pinnate leaf.

Odd Pinnately Compound

Leaflets are attached along an extension of the petiole known as a rachis. There is a terminal leaflet present and so an odd number of leaflets.

Even Pinnately Compound

Along an extension of the petiole, leaflets are attached; there are even number of leaflets.

Palmately Compound

At the tip of the petiole, leaflets are attached.

Leaf: Morphology, Anatomy, Modified Leaves (part 1)