Figs. 2.21-2.26. Transmission electron micrographs of transverse sections of the boundary zone and necrophylactic periderm of wounded peach bark. Bar = 1 m. Fig. 2.21. Portion of a shared boundary zone cell wall (CW) 8 days postwounding showing a simple pit area, and associated plasmodesmata (P), and lamellate suberin linings (S). Fig. 2.22. High magnification view of plasmodesmatal opening through the suberized portion of the boundary zone cell wall. Fig. 2.23. Shared boundary zone cell wall (CW), at 12 days postwounding with lamellate suberin linings (S) of differing thickness and the multivacuolate appearance of a senescent boundary zone cell. Fig. 2.24. Portion of necrophylactic phellem showing at bottom right a portion of the lumen and shared wall of the external phellogen daughter cell (PDC), the most recently derived suberized phellem cell (P1) with thin suberized secondary walls (S), and two older phellem cells (P2 and P3) showing thick suberized secondary walls (S) and senescing cell cytoplasm. Fig. 2.25. Closer view of shared necrophylactic phellem cell walls between P1 and P2 (CW1) and P2 and P3 (CW2) from Fig. 2.24. Note the fine light and dark lamellations of the suberized secondary walls (S) and the nonlamellate electron-lucid region of the secondary wall adjacent to the primary wall (arrows). Fig. 2.26. Organelle-rich cytoplasm of a phellem cell of a necrophylactic periderm sampled 14 days postwounding. Note lignified primary wall (CW), suberized secondary walls (S), plasma membrane (PM), rough endoplasmic reticulum (RER), mitochondrion (M), dictyosome (D), and associated vesicles.