Page 167 - Pharmacognosy-I (02-06-06-102)

4- Medullary rays, numerous, almost homogenous, 2-5 mostly 3-cells
wide. The cells are rectangular or slightly elongated. Their walls are
lignified, usually pitted with simple circular pits, occasional cells with
prisms of calcium oxalate and starch granules.

Quassia powder :

Yellow or pale buff, consisting wholly of lignified elements;
characterized by :
1- Numerous fragments of wood fibres comparatively thin walls and

large lumen with oblique linear pits, and having very long tapering
ends.
2- Fragments of vessels with very small oval bordered pits.
3- Fragments of rectangular and lignified wood parenchyma.
4- Fragments showing medullary rays in different aspects (in tangential
section, M.R. appear as lenticular or spindle shape structure, and as
elongated bands crossing the other elements in radial sections).
5- Presence of calcium oxalate prisms and few starch granules free or in
the parenchyma cells.

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