What is the difference between Palisade Parenchyma and Spongy Parenchyma?

Palisade Parenchyma:

1. These are present below the upper epidermis in dorsiventral leaf.

2. These are vertically eleongated parenchymatous cells and are tightly fitted to each other without intercellular spaces.

3. These are present in 3 layers.

4. These cells contain more chloroplasts. Chloroplasts are radially arranged in these cells. Thus, the upper part of the leaf is dark green.

Spongy Parenchyma:

1. These are present towards the lower epidermis in dorsiventral leaf.

2. These are oval-shaped parenchymatous cells and are loosely arranged with large air chambers.

3. These are multilayers.

4. These cells contain few chloroplasts, which are irregularly distributed. Thus, lower part one for the leaf is less green.