ILLUSTRATIONS 



Page. 

 Fig. 1. Map of the southeastern portion of the United States, showing the 



distribution of Dioscorea quaternata 12 



2. Map of the eastern portion of the United States, showing the distribu- 



tion of Dioscorea glauca 14 



3. Map of the eastern portion of the United States, showing the dis- 



tribution of Dioscorea paniculata and its variety glabrifolia 15 



4. Reproduction of Plate 7, " Dioscorea villosa, " from King and Lloyd's 



"Supplement to the American Dispensatory" 21 



5. Rhizome of Dioscorea glauca. Mountain form from the summit of 



House and Barn Mountain in Russell County, Va 22 



6. Rhizomes of Dioscorea paniculata from Agricultural College, Ingham 



Co., Mich 23 



7. Rhizomes of Dioscorea paniculata, var. glabrifolia, from Glenndale, 



Prince Georges Co., Md 24 



8. Rhizome of Dioscorea glauca. Typical drug from South Portsmouth, 



Greenup Co., Ky 25 



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