Cross sections in a leaf of coffea.

Coffea is a genus of plant in the family of Rubiaceae and it is native from tropical Africa with a few species from Asia. Coffee trees are evergreen shrubs with opposite leaves showing smooth margins.
The section below has been made in a portion of leaf fixed with FAA and embedded in paraffin. It was stained with astra blue – basic fuchsin.

The first micrograph illustrates tissues in main vein and other tissues in the mesophyll. Red circles: vascular bundles.

Feuille caféier nervure principale

Below: two micrographs of the section showing the mesophyll. Top: low magnification; bottom: higher magnification. Blue arrows: vascular bundles of lateral veins.

Feuille caféier mésophylle a.jpg


Going from top to bottom we have successively: the epidermis of adaxial face, the mesophyll that consists of one to two layers of palisade parenchyma (pp) and several layers of spongy parenchyma (pl), finally the epidermis of the abaxial face.

Several stomata (arrows) are observed in the abaxial epidermis (arrows). In the mesophyll chloroplasts in the two parenchyma are stained red (red arrows) and disposed around the central vacuole (v).