Page 115 - Pharmacognosy 2 PG303

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

Microscopical Characters
The leaf is dorsiventral with one palisade layer. The epidermal cells have wavy anticlinal
walls showing few diacytic stomata on the upper surface and numerous stomata on the lower one.
Glandular trichomes are of two types; capitate type (small, composed of unicellular stalk and
unicellular glandular head) and Labiaceous type (large, present sunken in a depression, composed
of unicellular stalk and cup-shaped glandular head of eight radiating secretory cells. Non-
glandular trichomes are uniseriate multicellular, with tapered ends and covered with warty or
streaked cuticle. Capitate and non- glandular trichomes are concentrated on neural epidermis.
Calcium oxalate crystals are absent. The stem is square in outline. Epidermis consists of cells with
nearly straight walls with few diacytic stomata and scattered trichomes. Cortex is parenchymatous
with four patches of collenchyma in the ridges; endodermis is followed by a narrow pericycle with
scattered groups of fibers. Xylem consists of spiral, reticulate and pitted vessels, wood fibers and
wood parenchyma, partially hollow and parenchymatous pith. The pollen grains are spheroidal
and smooth.

T.S. in Menthe leaf

T.S. in Menthe stem

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