THE DRUG DIOSCOREA. 



21 



true rliizomata became very scarce. Mr. H. M. Merrell, of Cincinnati, Ohio, 

 to whom we are indebted for this information, states that the first heavy ship- 

 ments of the false " wild yam root " to eas^tern houses were made about 1860, 

 whh?h article purchasers refused to accept, but after some correspondence, 

 ■coupled with the fact that the true wild yam could not at that time be obtained, 

 the parties concluded to receive it. Since then the two rhizomata have been 

 sold indiscriminately, although but little of the original drug is to be found in 

 the market. Eclectic physicians are aware of the difference between these 

 rhizomata and refuse to use the "false" variety, insisting that it does not 

 possess the medicinal properties, and can not safely be substituted for the 

 " true." In this connec- 

 tion we invite attention 

 to the accurate engrav- 

 ings of each variety of 

 the rhizomata in Plate 

 VII. [See fig. 4.] 



The rhizoma of Dios- 

 corca rillosa (PI. VII, 

 fig. 2) appears in market 

 in s 1 e n d e r contorted 

 pieces from one-fourth of 

 an inch to half an inch 

 in diameter, and often 2 

 feet in length. It is oval, 

 being flattened above and 

 below as it creeps in a 

 horizontal position be- 

 neath the surface of the 

 ground. It seldom throws 

 out branches, but occa- 

 sionally little protuber- 

 ances project from its 

 sides, being from one- 

 eighth of an inch to an 

 inch in length and about 

 one-third as large in 

 diameter as the primary 

 rhizoma. They are round- 

 ing at the extremity, 

 and seem to indicate an 

 abortive attempt of the 

 rhizoma to throw out 

 branches, but they do 

 not send up the vine. Along the upper side of the rhizoma are stem scars, which 

 are about three-fourths of an inch apart. The epidermis is brown, thin, and 

 scales off, more or less, upon drying, especially when the rhizoma is gathered in 

 the spring, but which is not the case with a good quality of it when dug in 

 autumn. The internal color of the dry rhizoma is whitish, or slightly straw 

 colored, when gathered in the autumn, but it is often brown when collected early 

 in the season ; there is no bark to it. Under a magnifying glass the texture of a 

 broken rhizoma apjiears mealy and perforated with numerous woody bundles. 

 Attached to the lower part of the rhizoma an abundance of strong, wirelike fibers 

 will be observed. * * * Dioscorea villosa has one of the firmest of rhizo- 



189 



Fig. 4. — Reproduction of Plate 7, " Dioscorea rillosa," from 

 King and Lloyd's " Siipplempnt to the American Dis- 

 pensatory." (Reduced one-third.) 



