THE WILLOWS OF ALASKA 333 



only species, with which Chamisso's description agrees. Dr. Ryd- 

 berg's recent application of Chamisso's name unalaschcensis to a 

 prostrate willow of the Juneau district of eastern Alaska is discussed 

 under Salix stolonifera. 



Dr. Rydberg's Salix rotundata^ a homonym for which he after- 

 ward substituted the name Salix cyclophylla^ as cited above, I am un- 

 able to distinguish from ovalifolia except as a common, and perhaps 

 indeed the prevalent, form with orbicular instead of oval leaves. Both 

 forms of leaves occvu- sometimes on the same plant, and all the other 

 characters that distinguish the oval-leaved ovalifolia from other wil- 

 lows are found also in the orbicular-leaved plant. 



19. SALIX STOLONIFERA Coville. Sprouting Willow; 

 Plate XLi, Figure i. 



Salix stolonifera sp. no v. 



Plant prostrate ; branches of the season smooth, i to 2 mm. in 

 diameter, the underground portions of old stems frequently develop- 

 ing slender subterranean ascending branches or stolons, usually less 

 than a millimeter in diameter; leaf blades commonly 1.5 to 3 cm. 

 long, oval to obovate, rounded or sometimes broadly acute at the apex, 

 either wedge-shaped or rounded at the base, sparingly provided when 

 young with a few early deciduous long straight hairs on the margins 

 and back, entire or with a few teeth near the petiole, glaucous beneath 

 and the reticulations not very conspicuous ; catkins terminating leafy 

 branches of the season, oblong to cylindrical ; scales black, obovate, 

 rounded at the apex, rather sparingly provided on both surfaces with 

 long straight white hairs inclined to be deciduous ; stamens two to 

 each scale, the filaments smooth ; ovary smooth or with some traces 

 of pubescence toward the apex, lanceolate, its stalk shorter than the 

 nectary, the style 1.5 to 3 mm. long, each of the stigmas bifid into two 

 linear segments ; capsule not glaucous. 



Type specimens in the United States National Herbarium, collected 

 June 10, 1900, at the railway station of Glacier, between Skagway 

 and White Pass, Alaska, by F. A. Walpole (No. 1075). 



The nearest relative of Salix stolonifera in Alaska is Salix ovali- 

 folia. The characteristic of the production of slender, leafless, sub- 

 terranean branches or stolons, which the specimens of stolonifera 

 usually show, I have never detected in ovalifolia. The length of the 

 styles is perhaps the easiest diagnostic character for one not familiar 

 with the two species. The leaves of stolonifera while similar in form 



