434 BOTANICAL GAZETIE [December 



doubtful if any of the so-called Sassafras leaves from the Dakota 

 Group are correctly named, and says that they will eventually 

 be recognized as interrelated with Platanus. While there is 

 much in favor of this view, especially in the case of some spe- 

 cies (which will be considered in their proper place), it is too 

 sweeping and will have to be qualified. 



The existing species is noted for its variable leaves, which 

 may be simple, 2, 3, 4, 5, or 6-lobed, and we quote from 

 Lesquereux to show with what certainty he regarded some of 

 his determinations. In speaking of S. platanoides, he asks **is it 

 referable to Sassafras, Aralia, or Platanus ?^3" S. mirabile he 

 originally referred to Platanus; he asks **what is Aspidiophyllum 

 defitatitm, Sassafras or Platanus ?" He says of 5. dissectiim that it 

 "has in the division of the lateral lobes the character of Aralia, 

 while by its size and general outline it is a Platanus, and still far- 

 ther by the basilar prolongation and dentate lobes it is merely a 

 variation of 5. mirabile, or in the still farther development of the 

 base it approximates Aspidiophyllum and Menispermites ; in 

 fact incomplete specimens of Aspidiophyllum which lack the 

 basal portion have generally been referred to Sassafras/' 



1 propose to consider the various fossil species in the light 

 of the modern leaf, and believe that the relations which are sug- 

 gested in the following pages, while necessarily imperfect, are 

 more natural than any treatment heretofore accorded them. 

 While all attempts at phylogeny are necessarily hypothetical, 

 especially when dealing with only one set of organs, such as 

 leaves, and many of these scattered and fragmentary, I have 

 not hesitated to theorize, believing that such attempts when 

 founded on careful study not only serve to coordinate existing 

 knowledge of the group but furnish starting points for new lines 

 of investigation, I exclude for the present any consideration of 

 the species from Europe or the Arctic region. 



The oldest species referred to this genus in America are 

 Fontaine's three Potomac species as follows : 



Sassafras parvifolium may be dismissed with the statement 



that there is nothing about this fragment of a small leaf to war- 



^3 Fl. Dak. Group, p. 231. 



