312 SUBTERRANEAN ORGANS 



darker in colour ; it is less contorted and shows the keel less distinctly, 

 but it has a very acrid taste, and is undoubtedly a good senega. It 

 is said to be derived from Polygala Senega, var. latifolia. 



White senega, from Polygala alba, Nuttall, is collected to some extent 

 in the southern States. The root is more slender than western senega, 

 has descending branches rather than spreading, and is lighter in colour. 

 It has no keel and a normal wood. The taste is much less acrid than 

 that of western senega, and it is presumably less active. 



Senega stems ; these are about 2 mm. thick, rounded, hollow ; they 

 contain non-lignified bast fibres by which they may be identified in 

 the powder. 



Other roots occasionally find their way into parcels of senega, 

 frequently as a result of careless collection, but the characters given 

 sufficiently distinguish the genuine drug. 



RHATANY ROOT 



(Radix Krameriae) 



Source, &C. Two varieties of rhatany root, commercially dis- 

 tinguished as Para rhatany and Peruvian rhatany, are official ; they 

 are derived from two distinct species of Krameria belonging to the 

 natural order Polygalece. 



1. Peruvian rhatany is the root of K. triandra, Ruiz and Pa von, 

 which grows on the mountain slopes of Peru and Bolivia. 



2. Para rhatany is presumably obtained from K. argentea, Martius, 

 a shrubby plant growing in Brazil. 



Rhatany root has apparently been used for many years by the 

 Peruvians for cleaning and preserving the teeth. The Spaniards 

 became acquainted with it in Lima and introduced it into Europe. 



Description. The root of Peruvian rhatany is large and knotty 

 at its upper extremity, but divides near the crown into several long 

 stout branches, from which again smaller branches proceed. ,The 

 larger pieces have a dark reddish brown colour and a rugged, scaly 

 bark ; the smaller are usually rather brighter and smoother, not 

 exhibiting any conspicuous transverse fissures. The bark, which can 

 easily be separated from the smaller roots, is rather fibrous, but the 

 wood breaks with a splintery fracture. The transverse section exhibits 

 a pale reddish or yellowish wood and a comparatively narrow reddish 

 brown bark occupying about one-fourth of the radius of a root of 

 medium size. The wood is dense, and marked with numerous narrow 

 medullary rays and minute vessels. The drug is quite odourless ; 

 the bark has a strongly astringent taste, but the wood is practically 

 tasteless. 



Para rhatany is usually imported in long, nearly straight, cylindrical 

 pieces, not often exceeding 15 mm. in thickness. They are well 





