Page 215 - Pharmacognosy 2 PG303

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

usually unbranched, 3-20 cm, mostly 5-7 cm long, 1-4 mm rarely up to 6 mm in
diameter, dark brick red to very dark brown. Externally, it is occasionally smooth,
closely annulared (about 8 annulations per cm), with thickened rounded almost
complete ring usually exhibiting transverse, very deep cracks, or even part of the
bark absent, sometimes bearing scars of remains of rootlets. Fracture is short in the
bark, splintery in the wood. Internally, it consists of a broad, grayish white bark
constituting about 2/3 of the root diameter, easily separable from the light yellow,
small, uniformly, dense, tough, non-porous central wood (distinction from undulated
and lesser striated Ipeca). Rhizome, is in short pieces, attached to the roots,
cylindrical, up to 2 mm in diameter. Externally, finely longitudinally striated,
wrinkled but without annulations, and showing scars of the leaves and occasional
buds. Internally, it shows a narrow bark and a ring of a dense yellowish xylem
surrounding a central pith, about 1/6 of the entire diameter.

Cartagena, Nicaragua or Panama Ipecacuanha; resembles Rio ipeca but differs
in being larger (3-9 mm thick) and greyish brown to reddish brown, with transverse
ridges at intervals of 1-3 mm. The ridges are about 0.5-1 mm wide extending about
half-way round the circumference and fading at the extremities into the general
surface level.

Microscopical Characters
Rio Ipeca root shows a narrow, dark brown cork, formed of several layers of thin-
walled cells, usually with brown granular contents. Cortex is formed of phelloderm
that is parenchymatous, containing numerous starch granules and scattered
idioblasts with bundles of raphides of calcium oxalate. Phloem is very narrow, with
short wedges of sieve tissue, but no fibers or sclerides, projecting into the
parenchyma. Xylem is wooly lignified, consisting of tracheids, with rounded ends
and linear pits, narrow tracheidal vessels with rounded lateral perforations near the
ends, substitute fibers with oblique, slit-like pits, containing starch granules, few
lignified fibers, and traversed by medullary rays. The latter are formed of 1 rarely
2 cells wide, lignified and containing starch granules. Primary xylem is 3-arch, at
the center. Rhizome shows a cork, a narrow parenchymatous cortex, an
endodermis, the pericycle, with thick walled, pitted, elongated rectangular
sclereids that present as single (sometimes double) discontinuous layers of
elongated rectangular cells with thick pitted lignified walls measuring 85120 µ
long, 20-25 µ wide and 20 p thick. The number of sclereids is defined as 33/mg
of stem powder. This figure is used to determine the proportion of' stern
admixed with the official root. Phloem shows fibers. Xylem is radiating with
fibers having linear pits and spiral vessels in the protoxylem and pith with
isodiametric lignified cells having thin, walls. Starch granules are rarely simple,
mostly compound of 2-5 sometimes up to 8 components. Individual granules are
oval, rounded 4- 10µ, rarely more than 15 µ in diameter.

172