THE FLORA OF THE SAINT EUGENE SILTS 



427 



Machira aurantiaca Nuttall {—Toxijlon pomiferum Rafi- 

 nesque). Texas to Missouri, and cultivated in the northern 

 states. 



Asimina triloba (L.) Dunal. Florida to Ontario. 



Fraxiniis quadrangulata Michx. Alabama to Ontario. 



None of these, however, as may be seen from their respective 

 ranges of distribution, is a strictly southern species and none is 

 represented in the Kootenay Valley flora, although the genera 

 Alnus, Hicoria, and Flatanus are common to both the Don and 

 the Kootenay. On the other hand the genera Ficus, Cehatha, 

 Cissampelos, and Vitis are elements in the Kootenay but not in 

 the Don. The conclusion, therefore, appears to be justified that 

 if the Kootenay Valley flora is of Pleistocene age it must repre- 

 sent an interglacial period distinct from and of a warmer climate 

 than either the Don, the Scarboro, or the Green's Creek, or else 

 that these periods represent colder regional conditions than 

 those which prevailed further west, and that the Kootenay flora 

 was a regional phase of one of these. And in this connection it 

 is of interest to note that the Cretaceous and Tertiary floras of 

 the Northwest contain a larger number of tropical elements than 

 do the contemporaneous floras of the middle and eastern parts of 

 the continent ; and, finally, we know that at the present time the 

 climatic conditions in British Columbia are milder than those of 

 Ontario,'" and I am informed, by those who are conversant with 

 the facts, that a critical examination and comparison of their 

 respective living floras shows similar regional differences. 



In summary it may be said that the flora of the Saint Eugene 

 silts, to the extent that it has thus far been investigated, appar- 

 ently represents one heretofore undescribed, and that it is in- 

 dicative of Tertiary rather than of post-Tertiary age ; but that 

 additional information would be necessary in order to compare 

 it satisfactorily with any described flora of either age, from 

 either the New World or the Old. 



50 Note. Saint Eugene Mission (49° 30' N. Lat.) has an annual mean tempera- 

 ture of 47° Farh. The Don Eiver valley (43° 45' N. Lat.) has an annual mean 

 temperature of 41° Farh. In other words the Saint Eugene Mission, about 375 miles 

 further north than the Don River region, has a mean annual temperature 6° warmer. 



