26 FIELD MUSEUM OF NATURAL HISTORY BOTANY, VOL. IV. 



Europe, we have found the fruiting involucres to be not only consider- 

 ably larger, but brownish rather than reddish, also much more pubescent 

 and the prickles nearly always more numerous. In its narrow, reddish, 

 remotely aculeate fruits, this species suggests the next, X. leptocarpum, 

 the type of which was collected likewise in western Vermont, about 

 three years earlier. Indeed, as a species, it seems to lie just half-way 

 between X. orientate and X. leptocarpum, and for a time we suspected 

 it of being a hybrid between these two species. But the apparent 

 absence of true X. orientale from all of North America 1 would seem to 



1 X. orientale L. Sp. PI. Edit. II, 2: 1400 (ex descript. et synon.; excl. loc.) 1763; 

 L. fil. Dec. II, PI. Rar. Hort. Upsal. tab. 17. 1763; Gaertner, Fruct. etSem. PI. 2: 

 tab. 164, f. 2. 1791; O. Hoffmann, Engler and Prantl Naturl. Pflanzenfamilien 4 T : 

 223, f. 112. 1889; X. elatius & majus Americanum etc., Morison PI. Hist. Univ. 

 Oxon. 604, sect. 15, tab. 2, f. 2. 1699; X. majus canadense Hermann, Hort. Lugd.- 

 Batav. 635. 1687 (fide Thellung); Lappa canadensis minori etc., Ray, Hist. PL i: 

 165. 1686 (fide Thellung); X. canadense Miller, Gard. Diet. Edit. VIII, no. 2. 1768 

 (cf. Thellung, Verhandl. Bot. Verein Brandenb. 50: 138. 1908; O. Hoffmann, 

 Engler and Prantl. Naturl. Pflanzenfamilien 4 V : 223. 1889); X. cuneatum Moench, 

 Meth. Suppl. 300. 1802 (Moench gave an entirely inadequate description, 

 "Xanthium, cuneatum, foliis cuneiformibus subtrilobis." He cited, however, 

 "Xanthium orientale Linnaei" and "Xanthium majus Americanum fructu spinulis 

 aduncis armato. Morison hist. III. p. 604, icon. Sect. 15 t. 2. f. 2 " for his two syno- 

 nyms); X. echinatum Wallroth, Monogr. Xanthium in Beitr. Bot. i n : 239. 1844 

 (Walpers Repert. Bot. Syst. 6: 152. 1846) non Murray; X. macrocarpum DC., Fl. 

 Franc. Suppl. 356. 1815. 



At various times in the past, Xanthium orientale L. has been reported as occurring 

 in America. Thus, as late as 1913, Britton and Brown (Illustr. Fl. Edit. II, 3: 346) 

 stated that this species was "naturalized in the West Indies." But an examination 

 of various specimens of Xanthium from the West Indies (among them a number from 

 the Herbarium of the New York Botanical Garden, and determined as X. orientale 

 L., evidently by Dr. Britton himself), fails to reveal to us a single specimen of X. 

 orientale. Indeed, all so-called specimens of X. orientale from the West Indies 

 that we have seen are referable to X. chinense Miller and differ very markedly 

 from X. orientale L. 



Great confusion has existed heretofore among many botanists as regards the 

 application of the name X. orientale. Linnaeus himself prefaced his original descrip- 

 tion with three synonyms ("Xanthium elatius majus americanum, fructu spinulis 

 aduncis munito. Moris, hist. 3. p. 604. s. 15. t. 2. f. 2. Xanthium majus canadense. 

 Herm. lugdb. 635. Lappa canadensis minori congener sed procerior. Raj. hist. 165 ") 

 and with the statement, "Habitat in China, Japonia, Zeylonia." 



If, on the one hand, we consistently follow the custom of taking earliest cited 

 synonyms with which to establish our concept of the species, there can arise practi- 

 cally no doubt. To be sure, Morison's figure has most of the prickles drawn arcuate 

 or even doubly bent, as in European plants of X. macrocarpum DC., while his 

 American material must surely have been another species (the Jamaica plants, for 

 example, undoubtedly belonging to X. chinense Miller). However, Morison definitely 



cited the Lappa Canadensis material of the Royal Garden of Paris as a 



basis for his species ("2. Elatius & majus Americanum, fructu spinulis aduncis 

 armato. Lappa Canadensis minori congener sed procerior, Hort. Reg. Par. E Vir- 

 ginia, Carolina & Jamaicensi Insula accepimus. V. icon., tab. aen. 2."). And (cf. 

 Thellung, Verhandl. Bot. Verein Brandenb. 50": 138. 1908) this cited material of 

 the Paris Garden was X. macrocarpum DC., for in the very year following the 

 publication of Morison's work, Tournefort (Instit. 1 : 439; 3: tab. 252, f. M. 1700) 

 cited and illustrated this "Lappa canadensis " material and his illus- 

 tration is positively of the X. macrocarpum DC. Thus, by taking in turn the earliest 

 cited synonym given by Linnaeus and by Morison, we find X. orientale L. to be the 

 plant later named X. macrocarpum DC. Thellung (loc. cit.) has come to the same 

 conclusion and he cites, furthermore, very strong evidence to show that the syno- 

 nyms of Hermann and Ray likewise belong with the true X. macrocarpum DC., i.e., 

 DC. FL Franc., loc. cit. Later, De Candolle (Prodr. 5: 523. 1836) unfortunately 



