APRIL, 1919. XANTHIUM MILLSPAUGH AND SHERFF. 37 



make an assumption to this effect purely gratuitous. Nor do we feel 

 inclined to regard our plant as an anomalous race or variety of X. 

 leptocarpum, since the arcuate character of its prickles is a character 

 that holds with a high degree of uniformity throughout the specimens 

 of the corresponding X. orientale of Europe. 1 



admitted other, specifically different material to his X. macrocarpum and so it is 

 highly important that, for a correct concept of the species, recourse be had only 

 to his original treatment in the Flore Francaise. The true X. macrocarpum DC. is 

 a plant with strongly hooked beaks and the prickles somewhat subremote, stoutish, 

 tending to be not only hooked at the apex, but also arcuate, often backwardly then 

 forwardly, from about the middle upward. 



On the other hand, there is good reason for discarding the Linnaean synonyms 

 entirely, since Linnaeus himself advanced them in an interrogative way. Thus, at 

 the close of his description, he asked the question, "Synonyma americanae plantae 

 an differant? " Clearly, Linnaeus did not establish his species upon certain synonyms 

 and then doubtfully refer the plant under observation to it; but he did base his 

 species upon the plant material studied, drawing up a (for that period) good descrip- 

 tion of it, and then to this species the interrogative mark and the wording of the 

 question show that he doubtfully referred the early synonyms. (This point is indeed 

 important, for in case a discrepancy did exist between the synonyms and the plant 

 of the description, it is evident that Linnaeus definitely advanced the description 

 and not the synonomy. But, fortunately, no such discrepancy appears to have 

 existed.) Linnaeus' doubts were evidently inspired by the fact that the cited 

 references, although agreeing with his plant, all had been regarded as pertaining to 

 American material. If we note his own citation of habitat, we find that he regarded 

 his Xanthium orientale as belonging to China, Japan and Ceylon. But, it happens 

 that his description is illuminated by a good, clear illustration published the same 

 year (1763) by his son, from plants at the Garden of Upsala. This illustration is 

 very decisive. It shows the Linnaean plant material of X. orientale to have been a 

 European plant (X. macrocarpum DC.), a plant that we have never known to come 

 from the Orient. 



In 1815, De Candolle (loc. cit.) created the name Xanthium macrocarpum as a 

 straight synonym for the Linnaean description of Xanthium orientale and for the 

 illustration by Linnaeus' son. He was impelled to create the new name X. macro- 

 carpum because the species had not been proved to grow in the Orient and because, 

 even if it had, the name orientale would be hardly appropriate, since the plant had 

 been collected in Languedoc: " La description de Linni, la description et la figure de 

 Linne" fils se rapportent parfaitement a notre plante; malgre" cela j'ai cru convenable 

 de ne pas lui conseryer le nom d' orientale, i. parce qu'il n'est pas prouv6 que cette 

 plante croisse en Chine, au Japon, a Ceylan; 2 . parce que cette habitation supposed 

 certaine, le nom d'orientale ne serait gure convenable, I'espSce se trouvant en 

 Languedoc. OElle a e'tte' trouve'e dans les vignes du bas Languedoc, par mademoiselle 

 Lucie Dunal." (Among various authentic French specimens of this species we have 

 seen an old one from De Candolle himself, collected in this same region, at Mont- 

 pelier. It is in the Torrey Herbarium, now at the Herbarium of the New York 

 Botanical Garden.) 



De Candolle's procedure in seeking to supplant the name X. orientale with the 

 name X. macrocarpum would not, of course, be sanctioned by the Vienna Code 

 (Internat. Rules Bot. Nomencl., art. 50. 1906), and clearly the name X. orientale L. 

 must be retained. 



Our search through botanical literature fails to show any true X. orientale to 

 have been collected in North America during recent times (Cf. Thellung. loc. cit. 141 : 

 "Indessen ist das echte X. orientale aus Nord-Amerika, wenigstens in neurerer Zeit, 

 nicht mit Sicherheit bekannt geworden.") 



1 On the eve of publication, we have received an admirable set of specimens 

 collected for us by Mrs. Nellie F. Flynn at Burlington, Vermont. The set includes 

 Xanthium chinense, X. speciosum, X. italicum, X. leptocarpum and X. curvescens. 

 We have deposited the material of X. curvescens in Hb. Field, nos. 481623, 481624, 

 481625, 481626, 481627, 481630; Hb. Gray ;Hb. N.Y. Its burs show a curious simula- 

 tion of those of X. orientale L., but are much smaller. It was found growing with X. 

 italicum and X. leptocarpum. This fact naturally leads to the inquiry as to whether 

 or not X. curvescens may ultimately prove to be of hybrid origin. 



