Hypodermis. The hypodermal cells are never intact because the mucilage contained in the cells swells when placed in water and breaks the thin side walls.
Upper Palisade Parenchyma. The palisade parenchyma is two layers in thickness. The cells of the outer layer are greatly elongated and are packed with chlorophyll. The inner layer of palisade cells is more irregular, and the cells are much shorter than the cells of the outer palisade layer.
PLATE 108
Cross-Section of Klip Buchu just over the Vein
A. Papillate upper epidermis.
B. Hypodermal cells with broken side walls, due to expansion of mucilage
contents.
C. Palisade cells, showing two cells filled with chlorophyll.
D. Palisade like mesophyll.
E. Endodermis.
F. Vascular strand of vein.
G. Conducting cells with spirally thickened walls.
H. Characteristic leaf mesophyll.
I. Short, thick palisade cells on the under side of leaf, just under the vein.
J. Under hypodermal cells.
K. Papillate under epidermis.
Spongy Parenchyma. The spongy parenchyma cells are branched; therefore, large intercellular spaces occur between the cells.
Under Palisade Parenchyma. The palisade cells of the under epidermis are short and broad, and they contain fewer chlorophyll grains than the upper palisade cells of the upper epidermis. These cells occur only under the veins.
Under Hypodermis. The under hypodermal cells are shorter and broader than the upper hypodermal cells.
Under Epidermis. The under epidermal cells are modified to form papillæ which are similar to the papillæ of the upper epidermis.
Fibro-Vascular Bundle. The cells composing the vascular bundle are sieve cells, vessels, and fibres.