650 



SCIENTIFIC AND APPLIED PHARMACOGNOSY 



Powder. Light grayish-brown; calcium oxalate in rosette 

 aggregates from 0.010 to 0.040 mm. in diameter; starch grains from 

 0.002 to 0.006 mm. in diameter, usually present in parenchyma and 

 cells of medullary rays; fragments of parenchyma containing a 



B 





M 



FIG. 287. Viburnum Prunifolium: A, transverse section of a part of the bark: 

 K, cork; C, cells of primary cortex; St, stone cells, which are distributed not 

 only in the cortical area but in the strands of phloem between the medullary 

 rays; Br, rifts between the parenchyma cells, which in the inner portion 

 causes a layering of the bark; Ca, calcium oxalate usually occurring in the 

 form of rosette aggregates; L, groups of sieve cells; P, parenchyma; M, a 

 medullary ray. B, tangential section showing the bi-convex groups of 

 medullary rays and surrounding tissues. C, fragments seen in the powdered 

 drug, the letters as in A . Drawing by Haase. 



yellowish-brown amorphous substance; primary bast fibers occa- 

 sional, having thick more or less undulate walls, which are slightly 

 lignified, the ends being somewhat obtuse; fragments of cork consist- 

 ing of more or less rectangular cells, having thick, lignified walls. 



