Page 53 – Epidermal and hypodermal layers of the leaf
Fig. 46 . Epidermal and hypodermal layers of the leaf. A. Transverse section of the abaxial side (on the ridge) of the basal (i.e., non-chlorophyllaceous) region of a fully developed leaf to show the epidermis (ep), the first and second rows of thick-walled hypodermal cells (h, h₁) and the third row of collenehyma-like hypodermal cells (h₂). Notice the comparatively thin outer wall of the epidermal cells (chiefly cuticle) and the thick lateral (i.e., radial) and inner walls of these cells, and the silica body (si) in each cell. Also notice the thick walls and pits in the hypodermal cells. B. Section of the ridge on the abaxial side of the transition (i.e., subchlorophyllaceous) region of a fully developed leaf, cut parallel to the surface, to show the cells of the first hypodermal layer. Notice the thick walls, the middle lamella and the many pits. X400.