Page 183 - Pharmacognosy 2 PG303

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

distinct continuous dark cambium ring, and a wide central part, usually paler than
the bark, with numerous dark islets, surrounded by tertiary cambia, also with
irregular lines of tertiary cambia which sometimes even form complete rings, and
dark points of resin cells. Jalap has a slight, characteristic, and somewhat smoky
odor and a sweetish, then acrid disagreeable taste.

Microscopical Characters
Cork, dark brown almost black, or numerous layers of brown thin-walled

cells, phloem, parenchymatous, constituting mostly the whole of the bark, rich in
cluster crystals of calcium oxalate and in starch, and with numerous resin cells in
longitudinal rows, and scattered isolated sclerieds with thick, pitted walls, especially
near the cork, secondary xylem, constituting the whole part inside the main
cambium ring, formed mainly of parenchyma containing starch granules and cluster
crystals of calcium oxalate, showing'' very narrow radiating area of vessels in short
radial rows near the cambium, and exhibiting numerous abnormally formed
concentric bundles of few vessels surrounded by tertiary cambia and phloem.
containing numerous resin cells and vessels.

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