Page 60 – Stomata
Fig. 53 . Stomata. A. Surface view of the abaxial epidermis of the chlorophyllaceous region of a mature leaf to show the guard cells of several stomata and their accessory cells. Notice the thick walls of the epidermal cells (middle lamella indicated by broken lines) and the irregular shape of those epidermal cells surrounding the guard cells. B and C. Transverse and longitudinal (i.e., radial) sections, respectively, of the same region of a similar leaf to show the structural details of a mature stoma. Notice the thick inner and lateral walls of the epidermal cells and those of the hypodermal cells, which are pitted, ac, anterior chamber; ep, epidermal cell; gc, guard cell; h, cell of first hypodermal layer; h₁, cell of second hypodermal layer; lac, lateral accessory cell; or, outer ridge; pac, polar accessory cell; pc, posterior chamber; ppw. pore passageway; sa, aperture; sac, secondary aerating canal; sacb, cells bordering on the secondary aerating canal; si, silica body; ssc, substomatal chamber; ssr, substomatal ring. X400.