Page 223 - Pharmacognosy 2 PG303 (1)

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

longitudinally wrinkled; 2.5-4 cm long and 3-6 mm in diameter.

Valerian; A&B, dried commercial rhizomes; C, diagram of a T.S. of an
aerial stem, D, diagram of T.S. of rhizome; E, diagram of T.S. of a stolon; F,
diagram of T.S. of root; G, h, detailed T.S. of stem; I , detailed T.S. of root;
a, starch; a.e, aerial stem; c, cortex; ck, cork; c.st, scar left by stolon;
cv, cavity; e, epidermis; eb, epilema; en, endodermis; ex, exodernis; hy,
hypodernmis 1,lacunae; m.r, medullary ray; p, pith; ph, phloem;
p.xy, protoxylem; r, root; rt, root-trace; scl. sclereids; xy,
xylem; v, vessel.

Microscopical Characters
Rhizome has epidermis of polygonal cells having the outer walls slightly
thickened. Cork, is immediately below the epidermis of up to 7 layers of lignified
slightly suberized, brownish large polygonal cells, with droplets of volatile oil.
Cortex is parenchymatous, with rather thick walled parenchyma, containing
numerous starch granules and traversed by numerous root traces. Endodermis is of
a single layer of a tangentially elongated cells containing globules of volatile oil.

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