CORTEX PRUNI VIRGINIAN.^. WILD CHERRY BARK. I 75 



tannin, yielding a greenish-black color with ferric salts, 

 and oxalic, citric, and malic acids are also present. 



CORTEX PRUNI VIRGINIANiE. WILD CHERRY BARK. 



"The bark of Frunus serotina, Ehrhart (nat. ord. 

 Rosacece), collected in autumn." U. S. 



This is one of the largest of American forest trees, 

 sometimes attaining a height of loo feet with a trunk 

 three or four feet in diameter. It is found from Hudson 

 Bay south to Mexico, abounding in Kentucky and Ohio. 

 The bark of the root is the most active. 



Description. — It comes in irregular pieces, i to 3 mm. 

 thick, the thinner the younger, of variable lengths, 

 slightly curved, usually deprived of the rust brown corky 

 layer, greenish, shining, with brown transverse markings. 

 The older the bark, the more the brown predominates. 

 The inner surface is darker, showing white longitudinal 

 striations. The fracture is brittle and granular. When 

 dry it has a faint odor, developing when moistened that of 

 bitter almonds. The taste is bitter, astringent, and 

 aromatic. 



Histology. — The cork when present is formed of several 

 rows of brown tabular cells. Imbedded in the cortical 

 parenchyma of thin- walled, polyhedral, tangentially 

 elongated cells are innumerable groups of sclerenchy- 

 matic cells closely arranged in radial rows. The in- 

 dividual sclerids are very thick- walled with small lumens, 

 concentric and radial markings. The medullary rays, 

 four to five cells wide, contain, as does the cortical 

 parenchyma, frequent agglomerated crystals of calcium 

 oxalate. The phloem is destitute of fibres, but, like the 

 outer portions of the bark, contains numerous groups of 

 sclerenchymatic tissue, irregular in size and shape. 

 Starch is present in small round grains in bark collected 

 in spring and fall. It fills the cells of the medullary rays 

 and the bast parenchyma. 



