336 SUBTERRANEAN ORGANS 



and should compare the root with 



(i) Belladonna root, which has no oil-glands and should be 



starchy, 

 (ii) Dandelion root, which has a small yellow wood and thick, 



ringed bark, 



(iii) Liquorice root, which has no oil glands, and much narrower 

 medullary rays. 



Constituents. Pellitory contains, as principal constituent, an 

 alkaloid, pyrethrine (also called pellitorine), which can be obtained 

 in colourless acicular crystals insoluble in water but soluble in 

 alcohol and possessing an intensely pungent taste. It is apparently 

 allied to piperine, which it resembles in some of its properties. 



The drug contains also inulin to the extent of about 50 per cent., 

 and traces of volatile oil. The sialogogue properties are due to the 

 pyrethrine. 



. Pellitory is used as a sialogogue in dryness of the throat 

 and as an addition to dentifrices. 



Adulteration. The root of Corrigiola littoralis, Linne (N.O. Illece- 

 bracece), is not unfrequ entry found in commercial pellitory root, 

 sometimes in considerable quantity. It closely resembles pellitory, 

 but may be distinguished by the small, warty protuberances with 

 which it is crowned and by the section which exhibits three or four 

 concentric circles, whereas that of pellitory is radiate. It is devoid 

 of the pungency and sialogogue properties of pellitory. 



The roots of Sonchus oleraceus, Linne, Achillea Ptarmica, Linne 

 and Chrysanthemum frutescens, Linne, are said to have been found in 

 the commercial drug ; none of them has the structure and taste of 

 pellitory root. 



German pellitory root, Anacyclus officinalis, Hayne, cultivated in Germany, 

 is thinner, has fibrous rootlets, is often crowned with the remains of leaves, and 

 has a similar pungent taste. 



Para Cress or Paraguay-Roux (Brazil, E. and W. Indies), the herb Spilanthes 

 oleracea, Jacquin (N.O. Compositce) has cordate, sinuate-dentate, opposite 

 leaves and yellow capitula without ray florets ; taste similar to pellitory root. 



ARNICA RHIZOME 



(Arnica Root, Rhizoma Arnicse) 



Source, &C. Arnica rhizome, or arnica root as the drug is com- 

 monly termed, consists of the rhizome and roots of Arnica montana, 

 Linne (N.O. Compositce), a small plant with a creeping perennial 

 rhizome, indigenous to central Europe and common in the meadows 

 on the lower mountain spurs. It should be collected in the autumn, 

 after the aerial parts have died down, and dried. 



