( 163 ) 
Gyrostachys stricta Rydb. Klondike Bottom (Williams) ; 
Sixty-mile Creek (Tarleton). 
Listera borealis Morong. _Five-finger Rapids (Tarleton). 
Sub-class DICOTYLEDONES. 
Family SALICACEAE. 
Populus tremulotdes Michx. Dawson (Williams). 
Populus balsamifera LL. 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, 
I-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. long, the 
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. Bebbcana 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 orbicularts Anders. Summit of White Pass (Wil- 
liams); Lake Bennett (Tarleton). 
Salix phiebophylla 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, pubescent 
