Page 39 - Pharmacognosy 2 PG303
P. 39

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

                 ▪  The  vitta  is  a  schizogenous  duct,  spindle-shaped  and      has  a  secreting
                     epithelium.    They  may  be  simple  (Fennel),  branched  (Anise),  few
                     (Coriander) or almost inconspicuous (Hemlock).

                 ▪  The vascular bundle is oval as in (Fennel) triangular (Caraway) or crescent-
                     shaped (Visnaga). It shows two lateral phloem bands with xylem in between
                     formed of fibers and few vessels. It may be accompanied by secretory ducts
                     (Visnaga) or with reticulate parenchyma (Fennel).

                 ▪  The innermost layer of the mesocarp may be differentiated as lignified cells
                     (Coriander)  or  porous  cells  (Visnaga)  or  nonporous  thickened  cells  (A.
                     majus), Endocarp mother cells are divided into groups of narrow parallel
                     cells which, may be parallel to each other forming parallel arrangement or
                     variously oriented forming parquetry arrangement.

                 ▪  The surface of the seed on the commissural side may be flat and the seed is
                     termed orthospermous (Fennel) or concave and the seed is colospermous or
                     has a longitudinal groove where it is called campylospermous.

                 ▪  The endosperm cells contain aleurone grains enclosing a globoid and one or
                     more micro-rosette crystals of calcium oxalate.

                 ▪  Umbelliferous fruits usually contain volatile oil secreted by the vittae, but
                     other  constituents  are  reported  in  Ammi  visnaga  which  contain  bitter
                     principles and in hemlock which contain alkaloids.








































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