190S.] TREES AND SHRUBS. 521 



leaves appear to be nearly full grown and the catkins are bursting 

 their capsules. 



Salix lutea Xult. Yellow Willow. 



This species is very conspicuous in the Athabaska-Peace delta, 

 where specimens taken on June 2, 1903, were just bursting into leaf. 

 Its twigs and catkins at that period impart a decidedly yellow effect 

 to the thickets. 



Salix myrtillifolia Anders. Myrtle Willow. 



This low willow was taken on the summit of the Nahanni Moun- 

 tains, where it assumes the form of a prostrate or trailing shrub, ris- 

 ing only 2 or 3 inches above the ground. Specimens taken there on 

 July 15, 1903, held catkins 30 mm. long; their capsules were just 

 bursting. On June 4, 1904, at the same place its leaves were nearly 

 full grown. At Fort Good Hope it occurs at the river level. 



Salix pseudo-myrsinites Anders. 



Taken at Fort Resolution and Fort Providence. Specimens col- 

 lected at the former place on June 21, 1903, had the leaves nearly 

 fully developed. At Fort Providence, on July 5, the fruiting cat- 

 kins were bursting their capsules. 



Salix myrtilloides Linn. Bog Willow. 



This species was taken on June 12, 1904, in a muskeg at Fort Nor- 

 man, where it is abundant. The leaves and catkins were nearly 

 fully developed at that date. 



Salix fluviatilis Nutt. Sandbar Willow. 



A willow taken at the mouth of North Nahanni River is identified 

 as this species. Sandbar willows, evidently of the same species, cover 

 the low islands and banks of the Athabaska, Slave, and Mackenzie 

 rivers throughout their courses. 



Salix nuttallii Sargent. Nuttall Willow. 



This willow was collected at Fort Simpson, where on May 2!) its 

 pistillate catkins were from one-half to three-fourths of an inch in 

 length, though the leaves had not appeared. 



Salix alaxensis (Anders.) Coville. Felt-leaf Willow. 



This beautiful willow, whose leaves are remarkably soft and felt- 

 like, is a northern type. We found it common along the southern 

 shore of Great Bear Lake, where its leaves had already turned 

 yellow on August 27, though its catkins were just opening. It ranges 

 south along the summits of the mountains. On the Nahanni Moun- 



" Owing to the difficulty of distinguishing most of the willows in the field, the 

 notes here given arc mainly taken from identified specimens. A few other 

 species were collected but remain uuidentitied. 



