i8o VVyoining Experiment Station. 



government report. This is the Rocky Mountain or plateau mem- 

 ber of a group which has for its eastern or Atlantic coast represent- 

 atives, 5". sericea and S. petiolaris, and for the Pacific coast 5. mac- 

 roc arpa.'' 



Rare ; observed only on Boulder Creek, August 26, 1894 (No. 

 1123). 

 Salix longifolia, Muhl. Neue Schr. Ges. Nat. Fr. Berlin, iv, 238 (1803). 



On sand bars and creek banks everywhere, common and variable. 



Laramie, June 16, 1894 (No. 245); near Lander, August 3, 1894 

 (No. 718); Cummins, July 26, 1895; (No. 1447). 



Salix macrocarpa, Nutt. 



I suppose this to be very rare in the state. 

 Centennial Valley, June, 9, 1895 (No. 1255). 



Salix monticolo, Bebb. 



Infrequent ; Centennial Valley, August 18, 1895 (No. 1733). 



Salix rostrata, Richards, Frank. Journ. App. 753 (1823). 



Our commonest Willoiu. 



Laramie, June 16, 1894 (No. 244); Centennial Valley, June 9, 

 1895 (No. 1303); also a low mountain form from Little Sandy, 

 August 30. 1894 (No. 1130). 



Salix sp. 



Only foliage but clearly enough not any of the foregoing. 



Populus acuminata, Rydberg, Bull. Torr. Club, xx, 50 (1893). 



Our handsomest Cottonwood as well as the most rapid growing of 

 our shade trees ; planted extensively in Laramie. 



Fine native specimens in Whalen Conon, July 17, 1894 (No. 560). 

 Rydberg s Cottoiiivood. 

 Populus angUStifolia, James, Long's Exp. i, 497 (1823). 



This is very frequent on the principal streams of the state, in 

 places forming considerable bordering groves, individual trees attain- 

 ing great size. 



Laramie, May 16, 1894 (No. 39). Black Cottomvood. 

 Populus balsamifera, L. Sp. PI. 1034 (1753). 



This is not frequent and I have not seen it except as single trees 

 here and there. 



Dubois, August 9, 1894 (No. 749); Cummins, July 29, 1894 

 (No. 1547). 



