HEMIDESMUS 341 



are attached to the upper extremity. The root varies in colour from 

 brick-red to dark brown or nearly black ; it is rather tortuous, nearly 

 cylindrical in shape, and marked with longitudinal wrinkles, and, at 

 rather distant intervals, with conspicuous transverse cracks. The 

 thin cork with which the root is covered shows a disposition to separate 

 from the cortex, and on one side may often be observed to be distinctly 

 raised above it. The transverse section exhibits a large, porous, but 

 not distinctly radiate yellowish wood surrounded by a thin greyish 

 or sometimes dark grey bark. The drug has an agreeable odour, 

 distinctly recalling tonco beans ; the taste is slightly aromatic and 

 sweetish, but not otherwise characteristic. 



FIG. 178. Hemidesmus root. Reduced. 



The student should observe 



(a) The rigid, tortuous character of the root, 



(b) The transverse cracks, 



(c) The easily separable cork, 



(d) The large yellowish wood ; 



and should compare the root with sarsaparilla, which is destitute of 

 transverse cracks, has a firmly adherent cork, and a small wood. 



Constituents. The agreeable odour is due to a crystalline odorous 

 substance resembling, but not identical with, coumarin. Of other 

 constituents little is known. 



Uses. It has been used as an alterative, but is now practically 

 obsolete. 



