Page 125 - Pharmacognosy 2 PG303 (1)

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

The leaf is isobilateral with a single palisade layer under each epidermis. The crystal layer
contains twin prisms, rarely clusters and microsphenoid crystals of calcium oxalate. The upper and
lower epidermises have wavy anticlinal walls, anisocytic stomata. Glandular trichomes are
numerous, of three types: branched, non- branched and clavate. Non- glandular trichomes are few.
The meristele is surrounded by endodermal starch sheath, bicollateral vascular bundle, radiating
xylem and groups of supernumerary phloem. The stem shows epidermis slightly elongated axially
covered with striated cuticle, less trichomes and stomata. The cortex with peripheral collenchyma
followed by parenchyma and endodermis. Small groups of pericycle fibers, continuous ring of
vascular bundles, central pith, and groups of perimedullary phloem. The calyx shows epidermal
cells more polygonal than those of the stem and radiating striations restricted around the stomata
and cicatrices. The pericarp shows two types of sclereids those from the apical region have
moderately thickened, pitted, and straight walls and those from the remainder of the fruits have
markedly wavy, unevenly thickened, pitted anticlinal walls. The seed shows a testa with very large
epidermal sclereids with distinctly wavy anticlinal walls. They are not thickened from the outer
walls but heavily thickened and striated from the inner and radial walls with a few simple pits.

T.S. in Hyoscyamus stem

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