THE WILLOWS OF ALASKA 329 



proach I have found to a subspeclfic differentiation is in some of the 

 specimens from the Pribilof and St. Matthew Islands in Bering Sea, 

 and the Shumagin Islands. In these specimens the leaves are orbicular 

 or nearly so and only about 2 to 3 cm. in diameter, v^hile the catkins 

 are shorter than usual, about 1.5 to 3.5 cm. in length. Occasionally 

 specimens are found which lack the glaucousness of the lower leaf 

 surface, a character on which Trautvetter based chiefly his separation 

 of diplodictya. 



16. SALIX GLACIALIS Anders. Icy Willow. 

 Salix glaciaiis A^V)E^s. Oefv. Vet. Akad. Foerh. 15: 131. 1858. 



A prostrate willow with smooth stems and buds, 

 small oval obtuse leaves 12 mm. or less in length, 

 smooth, or when young slightly appressed-villous 

 on the lower surface, glaucous on the back, entire 

 or with a few teeth toward the base, the catkins 

 ovoid to globose, several-flowered, the scales black 

 and nearly smooth on the outside, the ovaries 

 densely white hairy, and the style wanting. Its 

 foliage resembles that of ovalifolia^ though 

 smaller, but in the pistillate flowers it is very Fig. 24. Salix 



different from any species of the ovalifolia group, glactalts KndQrs.: a, 



The species is known only from the type P^^. * ^ ^ owenng 



o -r^ n twig, natural size: b, 



specmien collected by Lieutenant W. J. S. Pullen, pistyi^te flower, en- 



in 1S49, on the Arctic seacoast between Point larged six diameters. 

 Barrow and the Mackenzie River, and from speci- 

 mens collected at Point Barrow by John Murdoch, in 1882-3. Stami- 

 nate specimens and mature leaves are unknown. 



17. SALIX FUSCESCENS Anders. Bog Willow. 

 Sa/zx fuscescens AsBERS. Kongl. Vet. Akad. Handl. IV. 6: 97. 1867. 



A prostrate or trailing willow, with small smooth leaves glossy 

 above, glaucous beneath, of a rhombic-obovate form, the broadest 

 part distinctly above the middle, and usually with a few teeth toward 

 the narrowed base, the ovaries smooth, styles less than half a milli- 

 meter in length, and the pedicels two or more times the length of the 

 nectaries. It is a species of western Alaska, occurring from the peat 

 bogs of Kadiak Island and Cook Inlet westward to the tundra of the 

 shores and islands of Bering Sea and the Arctic Ocean, and is found 

 also in eastern vSiberia. 



Proc. Wash. Acad. Sci., August, 1901. 



