79 



Populus richardsoni, Heer. 



Bib : Geol. Surv. Can., 1887, 136 E : Trans. R.S.C., IV, 1886 ; VIII, 1902, iv, 46 : Fl. Foss. 

 Arct., I, 1868, 98 : U. S. Geol. Surv. Terr., 1873, 411 : Tert. Fl., 1878, 177. 



This apparently northern type is abundant throughout the Tertiary of the United 

 States, where it has been recorded by Lesquereux for the Green River group of Elko station, 

 Nevada, and the Fort Union group of Montana. It is, however, more abundant toward 

 the north, ranging as far as Greenland and Alaska. In Canada it has been found at the 

 Red Deer river, and in the Lignite Tertiary of Porcupine creek ; Calgary, Alberta, and the 

 Mackenzie river. 



Populus rotundifolia, Newb. 



Bib : Lat. Ex. Fl., XXXV, 51 : Proc. U. S. Nat. Mus., V, 1882, 506 : Trans. R.S.C., I, 1895. 



Newberry's record for this species shows that it is at present known in only two 

 localities in the United States — the Fort Union group of the Yellowstone river in Montana* 

 and Carbon station, Wyoming. The first Canadian record by Sir William Dawson in 1895 

 shows it to be a constituent of the flora of Burrard inlet, British Columbia, while 

 Lambe's collections of 1906 gave it a position in the Miocene of the Similkameen river. 



Populus speciosa, Ward. 



Bib . U. S. Geol. Surv. Bull. 37, 1887, 20 : Geol. Surv. Can., VII, 1894, 86, 37 C. 



A rare species first recorded by Ward from the Fort Union group of Clear creek ^ 

 Montana, but in 1894 obtained by Sir William Dawson from the Omineca river, British 

 Columbia. 



Populus subrolunda, Lesq. 



Bib : Geol. Surv. Can., 1877-78, 186 B : Amer. Jn'l. Sc, XLV, 1868, 205. 



This species has been recorded by Lesquereux from Carbon, Evanston, Rock creek and 

 Laramie plains, Wyoming ; but Coal brook, British Columbia, is the only station so far 

 known in Canada. 



Populus ungeri, Lesq. 



Bib : Trans. R. S. C, VIII, 1902, iv, 46 : Tert. Fl., 1878, 175. 



One of the rarest poplars in North America. In the United States it is known only 

 in the Denver group of Golden, Colorado. In Canada, it was obtained from the Red Deer 

 river in 1898 as recorded by Penhallow. 



Populus zaddachi, Heer. 



Bib : Cret. and Tert. Fl., VIII, 158, pi. XXXI, f. 8 : Mioc. Fl. Alask., II, pi. II, f. 5 : Mioc. 

 Fl. Sachalin, p. 25, pi. IV, f. 1-3 : Fl. Tert. Helv., Ill, 307 : U. S. Geol. Surv. Terr., 

 1871, 292. 



Populus zaddachi is one of the best characterized and most widely distributed species of 

 poplar in both Europe and America. In Alaska it is found at Port Graham. In the 



