The epidermis of G. angustifolia is made
up of long cells that intermingle with short
cells and stomata (Fig. 2a). The short cells, of
cork and silica, are grouped in pairs between
the long cells. The stomata, with their guard
cells, have an ovoid shape and horizontally are
longer than they are wide (Fig. 2b). The high
concentration of silica cells in the epidermis of
G. angustifolia’s culm contributes to the hardness
of its wood (Fig 2c).