Page 141 - Pharmacognosy-I (02-06-06-102)

Microscopic characters :

The Cork : formed of thin walled, rectangular cells with brownish
contents, arranged in regular radial rows and appearing polygonal in
surface view.

The Phelloderm consists of several layers of regular cells with dark

walls.
Cortex: rather narrow consisting of parenchyma cells containing few
starch granules, and showing numerous scattered idioblasts of
microcrystals of calcium oxalate mostly micro-prisms, and in the inner
part larger secretory cells are spaced at intervals.
Pericycle is undifferentiated parenchyma.
The Phloem : shows large characteristic phloem fibres, isolated or in
small groups in irregular radial rows.
The fibres are spindle-shaped with narrow lumen, stratified, strongly
lignified walls, having numerous funnel-shaped pits and blunt tips.
The medullary rays are 2-3 cells wide with rectangular and somewhat
radially elongated thin-walled cells.

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