Page 61 - Pharmacognosy 2 PG303

Pharmacognosy-2 (PG303) Level 2 Clinical Pharmacy-Pharm D

Microscopical Characters
1. Pericarp:
Epicarp is composed of polygonal tabular thick-walled cells and showing
occasional small prismatic crystals of calcium oxalate, few anisocytic stomata and
striated cuticle and no hairs.
Mesocarp is formed of three different zones. The outer zone consists of a
few layers of tangentially elongated parenchymatous cells usually collapsed
showing degenerated vittae as tangentially flattened cavities and longitudinally
traversed by 10 vascular strands with small spiral vessels. The middle zone is
formed of a broad layer of sclerenchyma consisting of strongly lignified pitted
fusiform fibres in 2 sinuous bands crossing each other at right angles, the outer 5
to 6 rows run longitudinally while the inner, 1 to 3 rows run tangentially, in the
secondary ridges almost all the cells run tangentially. The inner zone is composed
of 2-3 rows of large tangentially elongated thin-walled parenchyma.
The innermost layer of the mesocarp consists of flattened, hexagonal thin-
walled sclerenchyma.
Mesocarp on the commissural side shows no sclerenchyma but two large
elliptical yellowish-brown vittae.
Endocarp is formed of very narrow elongated thin-walled cells arranged in
variously oriented groups i.e., parquetry arranged.

2. Seed
The seedcoat is formed of polygonal brown cells with narrow collapsed layer
underneath. The endosperm is composed of thick-walled cellulosic cells
containing fixed oil and aleurone grains including globoid and micro-rosette
crystals rarely micro prisms of calcium oxalate.
3- Carpophore
Split, passing at the apex of each mericarp into the raphe and at the base to
the pedicel.

32