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SCIENTIFIC AND APPLIED PHARMACOGNOSY 



Inner Structure. (Fig. 140.) A periderm of numerous layers of 

 yellowish-brown cork cells; a phellogen and one or more rows of 

 cells of the phelloderm, the cells showing a tendency to collenchyma- 

 tous thickenings; primary cortex of starch-bearing parenchyma, 

 with whitish groups of bast fibers surrounded by crystal fibers; 

 secondary cortex or inner bark with a very characteristic, radial 

 arrangement of phloem and medullary rays, the phloem consisting 

 of wedges of small groups of bast fibers and parenchyma, separated 



FIG. 139. Original packages of Licorice Root (Glycyrrhiza) imported from 

 Persia. After a photograph by Parke, Davis & Co. 



by an almost continuous strand of leptome, the cells being very irreg- 

 ular in outline and with thick, highly refracting walls, medullary 

 rays 1 to 8 cells wide; wood wedges, broad, consisting of large tracheae 

 with yellowish walls, small compact groups of wood fibers and starch- 

 bearing parenchyma, alternating with the broad medullary rays; 



