)
Fig. 218 Mesophyll . Transverse section of a dorsiventral leaf.
mesophyll
the internal tissue of a plant leaf, except the VASCULAR BUNDLES. In dorsiventral leaves the mesophyll is differentiated into an upper palisade mesophyll and a loosely packed, lower spongy mesophyll. In isobilateral leaves there are upper and lower palisade mesophylls and a central spongy area. In C4 PLANTS there is yet another arrangement called KRANZ ANATOMY. All mesophyll cells contain CHLOROPLASTS (for PHOTOSYNTHESIS) which lie close to the edge of the cell in order to gain maximum light and gas supply. Mesophyll tissue contains numerous intercellular spaces which communicate with the atmosphere outside the leaf via STOMATA. See Fig. 218 .Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005