Page 25 - Pharmacognosy-II (06-PG 303)

(N.B.) It should contain not more than 2% stalks and other fore organic
matters and not less than 0.3% v/w essential oil.
Microscopic characters
I- Pericarp:

a- Epicarp: is composed of polygonal tabular thick-walled cells and
showing occasional small prismatic crystals of calcium oxalate, few
anisocytic stomata and no hairs.

b-Mesocarp: is formed of 3 different zones.

i - The outer zone :consists of few layers of tangentially elongated
parenchymatous cells usually collapsed, showing degenerated
vittae as tangentially flattened cavities and longitudinally traversed
by 5 vascular strands with small spiral vessels.

ii- The middle zone: is formed of a broad layer of sclerenchyma
consisting of strongly lignified pitted fusiform fibers in 2 sinuous
bands crossing each other at right angles, the outer 5 to 6 rows
run longitudinally (under the primary ridge), while the inner, 1
to 3 rows run tangentially( under the secondary ridge).

iii- The inner zone: is composed of 2 to 3 rows of large tangentially
elongated thin-walled parenchyma.

The commissural side shows no slerenchymatous fibers.

c- The innermost layer of the mesocarp:
It consists of flattened hexagonal thin-walled lignified sclerenchyma.
Mesocarp on the commissural side the presence of two large elliptical
yellowish-brown vittae.

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