THE I'LOKA OF THE SAINT EUGENE SILTS 



423 



If tlie floi'al elements, especially the specific elements, are 

 next analyzed in connection with their east and west distribution, 

 it may be seen that the flora as a whole is more nearly comj^ar- 

 able with that of eastern rather than with that of western North 

 America. Cchatha Carolina does not extend farther west than 

 Kansas; Menispermum canadcnse is not recorded from farther 

 west than Manitoba; Passiflora incarnata no farther west than 

 Missouri; and Vaccinium corymbosum no farther than Minne- 

 sota. Fagus grandi folia, the only existing American species of 

 the genus, does not extend farther west than AVisconsin ; and of 

 the dozen or more recognized species of Hicoria none extends 

 farther west than Minnesota, Kansas or Texas, with the excep- 

 tion of one southern species that occurs in Mexico. The genus 

 Plataiius has a distribution similar to that of Hicoria. P. occi- 

 dentalis occurs throughout the eastern United States to as far 

 west as Nebraska and Texas, and the only other two American 

 species are natives of the mountainous regions of the extreme 

 southwest and Mexico. The genus Tilia, which includes nine 

 American species, is also representative of the east rather than 

 the west. Of these T. americana alone extends as far west as 

 Manitoba ; and one species is native in the mountains of Mexico. 



Of the three species of Vitis listed, one, F. riparia, ranges 

 westward as far as Manitoba, the others to AVisconsin and Ne- 

 braska. 



Of the three American sjyecies of Almis listed, and the three 

 of Betula, only A. fruticosa and B. cordifolia have a far western 

 distribution. 



The six species of Quercus listed appear to be more or less 

 anomalous elements in the flora. Five are representative of 

 Mexico and Central America, and only one {Q. Prinus) is east- 

 ern in its distribution; and this species is somewhat doubtfully 

 included. 



If therefore, w^e are warranted in assuming as valid the com- 

 parison of the above generic and specific elements with the simi- 

 lar elements identified in the flora of the Saint Eugene silts, the 

 latter may be regarded as representing a flora approximating 

 that now in existence in the eastern United States, from about 

 latitude 38° southward. 



