306 BOTANICAL GAZETTE [april 



and similar forms as hybrids between Coreopsis and Bidens. Still 

 later, Britton (Bull. Torr. Bot. Club 20:280-281. 1893), em- 

 phasizing the instability of the barb-direction character for Bidens 

 frondosa L., and also separating the two genera on general grounds 

 rather than by one particular character, transferred six species 

 from Coreopsis to Bidens. The validity of these transfers has 

 since been accepted unhesitatingly by all prominent American 

 botanists who have critically studied the Eastern United States 

 species of Bidens, among them Wiegand (Bull. Torr. Bot. Club 

 26:401. 1899), Greene (e.g., Leafl. Bot. Crit. 1 : 200. 2 1906), and 

 Robinson and Fernald (Gray's Man. ed. 7. p. 839. 1908). It is 

 also implied by many other American botanists working upon the 

 species of other regions but following the same distinctions, a 

 singular case being that of Brandegee's description (Zoe 5:239. 

 1908) of Bidens alpina and Greenman's description (Proc. 

 Amer. Acad. 41 : 264. 1905) of Bidens sarmentosa. The achenes are 

 described for B. alpina as "nearly smooth; awns none or two 

 varying from 1 mm. long to rudiments, corneous and not barbel- 

 late"; for B. sarmentosa, as "glabrous or sparingly hispidulous, 

 awnless or with reduced awns." But, on investigation, these 

 species are found to be identical; in turn, B. sarmentosa, which 

 from priority of publication would otherwise stand as the accepted 

 species, is found to match 3 in every character Coreopsis antlic- 

 moides DC, having achenes described (DC. Prodr. 5:573. 1836) 

 as " (immaturis) linearibus glabris brevissime bidentatis." Thus, 

 a species placed by DeCandolle in Coreopsis, evidently because 

 of its very short awns, was independently referred by Brandegee 

 and by Greenman, about 70 years later, to Bidens, evidently 



2 Thus, Greene refers to Bidens a plant (" B. tenuissima") with "erect, upwardly 

 barbed awns." 



•» I have examined several authentic cotypes of B. alpina, the type and numerous 

 authentic cotypes of B. sarmentosa, also several cotypes of "Coreopsis antkemoides" 

 {Bidens antkemoides Sherff, Bot. Gaz. 56:493. 1913). War conditions in Europe 

 have precluded for the present my examination of DeCandolle's type at Geneva. 

 However, the characters cited by DeCandolle and his comparison of this species 

 with Anthemii arvensis, which it at times simulates in habit to a remarkable degree, 

 leave no doubt that the cotypes examined (in Herb. Brit. Mus. and elsewhere) truth- 

 fully represent the type. 



