8 THE SOUKCE OF THE DRUG DIOSCOKEA. 



secretary of the Linna?an Society, very courteously looked into the 

 matter, and wrote as folloAvs: 



On referring to the Linnsean lierbarium, I found only one American speci- 

 men. * * * At the bottom of the sheet is the note by Linne himself, " 6 K 

 sativa," to which Smith has added in pencil, " non est;" K = Kalm. I do- not 

 find any specimen named by Linne " villosa " in his herbarium, but as sativa 

 is an lOast Indian species, and the specimen is of Kalm's collection, it is patent 

 that there is a blunder. 



Since Kalm is not mentioned in the treatment of Dioscorea villosa, 

 and since no localities but Virginia and Florida (these obviously 

 refer to the citations from Gronovius and Plukenet) are mentioned 

 by Linna'us, we can by no means typify D. villosa by the Kalm speci- 

 men." The species must therefore be interpreted in the light of the 

 diagnosis and synonymy given by Linnaeus. 



Doctor Rendle, of the British Museum, has kindly sent a photo- 

 graph and description of the specimen which Clayton collected in 

 Virginia and sent to Gronovius. It is identical with the most widely 

 distributed Dioscorea of our range — not the most characteristic 

 species of Virginia, to be sure, but the one which would probably have 

 been collected in the coastal part of the State. In the matter of 

 pubescence the species varies considerably, but, according to Doctor 

 Rendle, the Gronovian specimen is glabrous except for puberulence 

 on the veins and venules of the lower leaf face. It can not, there- 

 fore, have been seen by Linnseus at the time he wrote the Species Plan- 

 tarum, for he would not have applied the adjective " villosa '" to an 

 almost glabrous plant. As a matter of fact, the specific name came 

 from Plukenet's " Bryoniae nigrae similis floridana, muscosis floribus 

 quernis, foliis subtus lanugine villosis, medio nervo in spinulam 

 abeunte." This characterization and the figure which accompanies 

 it are altogether vague, and in at least one point, the description of 

 the flowers as four parted, not even in accord with the generic 

 concept of Dioscorea. If we typify Dioscorea villosa by the 

 Gronovian specimen, as there is some warrant for doing because of 

 the fact that the first-cited locality in the Species Plantarum is 

 Virginia, we must call a widely distributed and abundant plant by 

 a name which is altogether inept. Richard'' found a way out of 

 this difficulty by renaming the northern plant, which is identical 

 with the Gronovian specimen. His treatment follows : 



D. [paniculata] caule laevi foliis brevibus, cordatis, acuminatis, racemo masc. 

 e plurimis racemulis filiformibus quasi-paniculatim composite ; capsula rotun- 

 da ta glabra. 



''A photograph of Kalm's specimen, kindly sent by Doctor Jackson, shows 

 that it should be referred to the species treated in this paper as Dioscorea 

 paniculata. 



^Michaux, Flora Boreali-Americana (1803), ii, p. 239. 

 189 



