TREES AND SHRUBS FURNISHING MEDICINAL BARKS. 



39 



The rather small, insignificant greenish flowers are produced in umbels, or 

 clusters, and are followed by bhuk. ovoid. 3-seeded berries, of a somewhat 

 insipid taste ( fig. 35). 



Another species. — Several species of Rhamnus occur in the cascara district, 

 only one of which, however, may be said to enter into competition with 

 the official cascara. and that is the one which is supposed to have been 

 first introduced in medicine. It is known as wild coffee or coffee-berry {Rham- 

 nus californica Esch.). At the present time, however, it is seldom collected, 

 and then only because it may be mistaken by collectors for the official bark. 

 According to the nineteenth edition of the United States Dispensatory (1907), 

 R. californica "is chiefly distinguished from the official species by its leaves 

 being thin, and when not smooth having a short close pubescence, and the 

 primary veins of the under surface 

 not nearly so numerous, straight, or 

 fine as those of R. purshiana." 

 Rhamnus purshiana is abundant in 

 the northern part of California and 

 only sparingly found in the southern 

 portion, whereas exactly the opposite 

 is true of R. californica. Professor 

 Rusby (United States Dispensatory, 

 nineteenth edition, 1907) is of the 

 opinion that as a further distinguish- 

 ing mark in the leaves the channel of 

 the midrib of R. californica is "alto- 

 gether absent, or shallow, or incon- 

 spicuous." 



It is very difficult to distinguish 

 the barks of these two species by 

 their gross characters alone, but a 

 microscopical examination will show 

 structural differences sufficiently dis- 

 tinct to aid in the recognition of the 

 barks. a In the powdered state the 

 two species may be distinguished by 

 means of color tests. 6 



Description of bark. — The cascara 

 sagrada of commerce occurs in curved 

 or quilled pieces, the outer surface of 



which is reddish brown, and usually covered with growths of light-colored or 

 grayish lichen, wrinkled and somewhat fissured. The inner surface of the bark 

 is smooth and marked with very fine lines; at first the inside is yellowish, but 

 with age it turns a dark brown color. The whole breaks with a short, sharp, 

 yellowish fracture, and has a somewhat aromatic odor and an exceedingly bitter 

 taste. The saliva is colored yellow by it, and anything with which the bark 

 corner in contact for any length of time will also be stained yellow. Cascara 

 sagrada is official in the United States Pharmacopoeia. 



Fig. 35.- 



-Cascara sagrada {Rhamnus pursh- 

 iana). leaves and fruits. 



a Rusby. H. H. Cascara Sagrada and Its Allies. Proc. Amer. Pharm. Assoc, 

 1890, pp. 203-211. 



h Sayre. L. E. Frangula and Cascara Barks. Amer. Jour. Pharm., 1897, pp. 

 126-134. 

 139 



