452 POWDERED VEGETABLE DRUGS 



158. (Figs. 155 and 156.) PRUNUS SEROTINA. Wild- 

 cherry Bark. U. S. 



Fl. ex. 20. Inf. 40. 



Wildekirschenrinde, G. Ecorce de cerisier, Fr. 



The bark of Prunus serotina Ehrhart, Rosaceae. 



Bright reddish brown. 



Somewhat aromatic, recalling bitter almonds. 



Bitter and astringent. 



Numerous typical thickwalled, porous sclerenchyma cells. Bast 

 fibers comparatively few; some branching, irregular, sclerenchymatous. 

 Aggregate and prismatic crystals of calcium oxalate abundant in bark 

 parenchyma cells. (Fig. 156.) 



Ash 4 per cent. 



The bark of choke cherry (Prunus virginiana Miller) (Fig. 155) 

 differs from the above in the absence of sclerenchyma cells; bast fibers 

 normal and branching, are very abundant; aggregate crystals very 

 numerous and some quite large; prismatic crystals are wanting; middle 

 bark parenchyma cells small arid loosely united. 



Fig. 155. PRUNUS VIRGINIANA. (Choke Cherry.) 



a. Bast, simple and branching. 

 6. Parenchyma cells. 

 c. Aggregate crystals. 



