686 



BOTANY AND PHARMACOGNOSY. 



the rhizomes and the chaff are removed. Usually the drug con- 

 sists of the stipes only, which are separated from the rhizome, 

 the periderm being removed (Fig. 277a, A). The drug is care- 

 fully dried and preserved and should not be used after it loses its 

 green color. 



Description. — Of horizontal or oblique growth, 5 to 15 cm. 

 long and i to 2.5 cm. thick, mostly covered with nearly cylindrical. 



Fig. 277a. A, B, Aspidium Filix mas showing a decorticated stipe and piece of 

 rhizome (A), and rhizomes with stipes attached (B); C, probably the rhizome of Osmunda 

 Claytoniana, which is sometimes substituted for Aspidium. 



slightly curved stipe-remnants (Fig. 277a), which are about 

 25 mm. long and 5 to 10 mm. thick, between which is a dense 

 mass of dark-brown, glossy, transparent and soft-chaffy scales; 

 internally spongy, pale green, becoming brownish with age; in 

 transverse section showing an interrupted circle of about six {A. 

 marginale) or seven to nine (A. Filix mas) groups of fibro- 

 vascular tissue, each of which is surrounded by an endodermis- 

 like layer ; odor sHght, taste acrid, somewhat bitter and nauseous. 



