Atlas of plant and animal histology

The parenchyma of the leaves is known as mesophyll. Mesophyll parenchyma cells contain many chloroplasts and are usually arranged in two ways: palisade and spongy. The palisade parenchyma is located close to the upper epidermis of the leaf. It contains elongated cells arranged in layers with small intercellular spaces. The number of layers depends on the species and the light intensity. The spongy parenchyma is found close to the lower epidermis. It is made of more rounded cells, not arranged in layers, and with conspicuous intercellular spaces. It is suitable for gas excjange between the leaf and its surroundings.

The photosynthetic parenchyma can be found outside the leaves, such as in green stems, petioles, developing fruits, and also in adventitious roots.

More images