(i6 3 ) 



Gyrostachys stricta Rydb. Klondike Bottom (Williams) ; 

 Sixty-mile Creek (Tarleton). 



Lister a borealis Morong. Five-finger Rapids (Tarleton). 



Sub-class DICOTYLEDONES. 



Family Salicaceae. 



Populus tremuloides Michx. Dawson (Williams). 



Populus balsamifera L. River bank opposite Dawson 

 (Williams). 



Salix myrtillifolia Anders. Below White Horse Rapids ; 

 Dawson Swamp (Williams) ; Lake Bennett (Tarleton). 



Salix perrostrata Rydb., sp. nov. 



A shrub, 1-4 m. high with grayish, rough and scaly bark ; 

 branches yellow or the youngest tinged with red, at first 

 finely pubescent ; leaves obovate-lanceolate or oblanceolate, 

 when young finely silky, in age glabrate, 2-4 cm. long, 

 1-1.5 cm. wide, acute at both ends, and with undulate 

 margins, light green above and paler beneath ; petioles 2-6 

 mm.; stipules minute, deciduous; aments somewhat leafy 

 bracted, almost sessile; the staminate 1—1.5 cm - l° n g> tne 

 pistillate in fruit 2-3 cm.; capsule conic, long-rostrate; 

 stigma subsessile. 



Black Hills of S. Dakota and Pine Ridge, Neb., to Col- 

 orado and Alaska, May-June. (S. Bcbbiana Rydb. Cont. 

 U. S. Nat. Herb. 3: 523, mainly, not Sarg.) 



Type collected near Hermosa, Black Hills of South Da- 

 kota, 1892, P. A. Rydberg, 1018. Hillsides, Dawson, R. 

 S. Williams. 



Salix anglorum Cham. Summit of White Pass (Wil- 

 liams). 



Salix orbicularis Anders. Summit of White Pass (Wil- 

 liams) ; Lake Bennett (Tarleton). 



Salix phlebophylla Anders. Summit of White Pass. 



Salix chlorophylla Anders. ? Dawson Swamp (Williams). 



Salix longistylis Rydb. sp. nov. 



A shrub, 4-5 m. high, with stems 13-15 cm. thick, the 

 bark of the branches greenish brown or purplish, pubescen t 



