Fig. 3.5-3. Paradermal section through the leaf of ground ivy (Glecoma, in the mint family, not a real ivy). The long strands with helical red bands are xylem cells that conduct water. At this point, focus on the larger, rounded parenchyma cells that touch the conducting cells (arrows indicate three of many). The conducting cells are slightly scalloped because the parenchyma cells pressed so firmly against them while they were maturing. The dark material in all the parenchyma cells are chloroplasts packed so closely that it is difficult to tell that they are individual bean-shaped organelles. In parenchyma cells that contact xylem conducting cells, chloroplasts are located along the walls away from the conducting cell. This leaf – like most material used for general studies of plant anatomy – was prepared by embedding it in wax and then cutting it into sections about 10 to 12mm thick. This is too thick to be able to see labyrinthine walls, but almost certainly, the parenchyma cell walls that touch the xylem conducting cells are transfer walls with labyrinthine walls. To be certain, it is necessary to use either scanning or transmission electron microscopy. If these cells do indeed have labyrinthine walls, then they are transfer cells.