Page 163 - Pharmacognosy 2 PG303
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Pharmacognosy-2 (PG303) Level 2 Clinical Pharmacy-Pharm D
parenchymatous xylem and enclosing a few of the xylem vessels. In orizaba jalap,
the ordinary original cambium is replaced, as the root increased in size, by
successive cambia of limited period of activity developed in the pericycle, producing
vascular bundles in rings. In Dandelion, the xylem is small, central surrounded by
unusually developed phloem, formed of concentric rings of sieve tissue and
laticiferous vessels alternating with parenchyma. In Ipecacuanha, the xylem is
small and dense, the phloem is weakly developed as a narrow wedged ring around
the xylem, and a very wide starchy parenchymatous phelloderm, constituting the
secondary cortex, is present.
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