166 



SCIENTIFIC AND APPLIED PHARMACOGNOSY 



QUERCUS. White Oak Bark. The bark of Quercus alba (Fam. 

 Cupuliferae), a tree indigenous to the eastern and central United 

 States and Canada. The bark is collected in spring from the branches 

 and trunks of trees from ten to twenty-five years of age, and deprived 

 of the periderm and dried. 



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Description. In flat, irregular, more or less oblong pieces 5 to 30 

 cm. long, 10 to 20 mm. in diameter, 2 to 4 mm. thick; outer surface 

 light brown, longitudinally striate, with occasional patches of dark- 

 brown periderm; inner surface yellowish-brown, coarsely striate and 

 fissured longitudinally, and with detachable bast fibers; fracture 



