262 HISTOLOGY OF MEDICINAL PLANTS 
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 papillz which are similar to the papille of the upper 
epidermis. 
Fibro-Vascular Bundle. The cells composing the vascular 
bundle are sieve cells, vessels, and fibres. 
The sieve cells are small and the walls are white and 
angled. 
The vessels have thick, white, angled walls. 
The bast fibres are rounded in outline and the walls are thick 
and white. 
Endodermis. The endodermal cells encircle the fibro-vascu- 
lar bundles. The cells are large, thin-walled, and oval in shape. 
Secretion Cells. Near the edges of the leaf are schizoge- 
nous secretion cavities surrounded by thin-walled secretion 
cells. 
POWDERED KLIP BUCHU 
When the leaf is powdered (Plate 109), the cells are quite 
as characteristic in appearance. The upper epidermal cells 
(1) have thick-beaded, yellowish-white walls and papillate outer 
walls. No stomata occur on the upper surface. The under 
epidermis (2) with numerous stomata, is surrounded by the 
characteristic guard cells. The end walls are beaded as on the 
upper surface. The palisade cells (3) appear as in the cross- 
section. The conducting cells (4 and 4) are of the spiral and 
pitted type. The papillae (5 and 5) are very abundant in the 
powder and very characteristic. The fragments of the epidermis 
(6) are also abundant. The mesophyll (7) is characteristic, as 
it retains its form when powdered. The fibres (8) are usually 
associated with the conducting cells; occasionally they are 
found free as in the illustration. 
