Page 108 - Pharmacognosy 2 PG303
P. 108
Pharmacognosy-2 (PG303) Level 2 Clinical Pharmacy-Pharm D
a curved tube enclosing the bifid stigma, each anther ends with a tuft of hairs at the apex; ovary
inferior, bilocular, bicarpellary. Fruit: is inflated capsule, dehiscing by 2 pores at the summit,
ovoid or ellipsoidal, 5 to 8 mm. Long, light brown, inferior, crowned by the remains of the calyx,
with 10- ribbed, membranous pericarp; internally bilocular, containing numerous seeds arranged
on an axile placenta. Seeds: are minute, oval oblong, 0.5 to 0.7 mm. Long and about 0.3 mm.
Wide, reddish- brown, with fine, elongated, polygonal reticulations.
Microscopical Characters
Leaf: is dorsiventral, having a single palisade layer and spongy tissue, containing minute
droplets of oil. Midrib has a central large vascular bundle, which shows the presence of laticiferous
vessels in the phloem, and two subepidermal collenchyma. Upper epidermis consists of papillosed
cells with nearly straight beaded anticlinal walls, striated cuticle and trichomes. Stomata is absent
on upper epidermis, except on teeth. Lower epidermis consists of wavy walled cells, numerous
anomocytic stomata and trichomes. Trichomes are of non- glandular type; large, up to 0.6 mm.
Long, unicellular conical and covered with warty cuticle. Numerous water- pores occur on the
upper surface of each marginal teeth and some on the edges. Stem: has 6 rounded angles and 2- 5
wings as shown in T.S. and has an epidermis consists of axially elongated, beaded straight- walled
cells with striated cuticle, few anomocytic stomata and numerous trichomes (up to 1.2 mm long)
similar to those of the leaf cortex is formed of chlorenchyma 9collenchyma is present in wing
region) followed by well- marked endodermis with distinct casparian strips. Stelar tissues: is
formed of parenchymatous pericycle, a continuous ring of vascular tissue in which phloem
encloses a network of laticeferous vessels (stained with iodine) and a central wide pith of lignified,
thin- walled pitted parenchyma. Pollen grains: are nearly spherical with 3 germinal pores and
smooth or fine warty exine. Pericarp: is longitudinally traversed by several vascular bundles and
showing mesocarpal irregular lignified sclerides. Seed Coat: shows elongated polygonal tabular
epidermal cells with lignified thick, browns anticlinal walls.
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