Page 55 – Leaf margin and apex
Fig. 48 . Leaf margin and apex. A. Margin of the chlorophyllaceous region of a fully developed leaf in transverse section to show the thick hypodermal layer here. ep, epidermal cells; h, h₁, h₂, h₃, and h₄, successive rows of hypodermal cells; tb, epidermal and hypodermal cells surrounding the stalk of a trichome, cut in tangential section; gp, ground parenchyma cells; fs, fiber strand cut in cross section. Xl00. B. Tip of a fully developed leaf in transverse section to show, in a, a diagram delimiting the various zones of tissue and a sector of a, as indicated by the dotted lines, to show the details of structure, in b. h, in a, epidermal and hypodermal layers, consisting of one row of epidermal cells (ep) and the hypodermal rows h, h₁, h₂, and h₃, in b; ws, water storage tissue; at, assimilatory tissue (chloroplasts not shown); cb, consolidated central-vascular bundle, consisting of vascular elements from several basiscopic bundles. x, xylem; p, phloem; s, sclerenchyma. A, X20; b, X100.