350 



SUBTERRANEAN ORGANS 



in length, but larger specimens attain as much as 8 or 10 cm. in thickness 

 and a metre in length ; they are nearly cylindrical in shape, tapering 

 gradually towards the tip but slightly enlarged at the crown, and there 



FIG. 181. Portion of a small Jjcammony root. Natural size. 



rugged from the remains of aerial stems. The drug is of a greyish 

 brown colour, hard, heavy, and woody, rough and furrowed externally, 

 and often spirally twisted. Lateral rootlets occasionally spring from 

 it and commonly split into fibrous strands. It breaks with an irregular 

 fracture, from which short fibres (strands of wood) project. Internally 

 the root is whitish, and the transverse section, when smoothed, exhibits 



an abnormal and characteristic 

 structure. There is no distinct 

 central wood, but the root ex- 

 hibits instead several not very 

 well-defined circles, in each of 

 which a central portion con- 

 taining groups of vessels can be 

 distinguished from a surround- 

 ing parenchymatous portion ; 

 in the latter numerous dark 

 points (resin cells) can be dis- 

 cerned with a lens. The root 

 is invested with a thin bark, 

 which however is not very 

 conspicuous. 1 The whole of the 

 parenchymatous tissue contains 

 starch. 



The root has a characteristic 



odour distinctly recalling that of jalap, and especially noticeable when 

 the surface is freshy cut ; the taste is sweetish and slightly acrid. 

 The student should observe 



(a) The large size and greyish brown colour, 



(b) The characteristic jalap-like odour, 



FIG. 182. Scammony root. Transverse 

 section. (Pharmaceutical Journal.) 



1 For further anatomical details see Planchon and Collin, Les Drogues simples, i. 623. 



