19 iq] SCHNEIDER— AMERICAN WILLOWS 47 



representing a rather dwarfed alpine form. The glabrousness or 

 pubescence of the ovaries, a character on which usually so much 

 reliance is placed, cannot always be taken for a decisive taxonomic 

 character. In my notes on the species of the section Ovalifoliae 

 [I.e.) I was able to show that many species with hairy ovaries develop 

 a more or less glabrescent or glabrous variety, or vice versa. 



4. S. NIVALIS Hooker, Fl. Bor.-Am. 2:152. 1839; Nuttall, N. 

 Am. Sylva i : 77. pi. 19, fig. sinistra inferior. 1843 ; Rydberg in Bull. 

 N.Y. Bot. Card. 1:262. 1899; Ball in Coult. and Nels., New Man. 

 Rocky Mt. Bot. 139. 1909. — S. reticulata c nana And. in Ofv. K. 

 Vet.-Akad. Forh. 15:133. 1858, excl. specim. e Groenl. et Spitzb. — 

 5. reticulata fi nivalis And. in DC, Prodr. 16^:301. 1868. — The 

 type of this "elegant and very diminutive shrub" (Nuttall) was 

 collected "near the summits of the peaks in the Rocky Mountains" 

 by Drummond between lat. 52-56°. It occurs most frequently in 

 the alpine region of the Rockies of Alberta and British Columbia, 

 and to a certain degree also on the Tobacco Root Range (Pony 

 Mountains), on Observation Mountain and Mt. Chauvet in 

 southern Montana, and on the Electric Peak in northern Yellow- 

 stone Park. It is also mentioned by Piper from Mt. Rainier, 

 Washington. There are a few "specimens from Colorado (E. L. 

 Greene, no. 517, m.: G.; probably from near Golden City) and 

 from southeastern Utah (Rydberg and Garrett, no. 8787, m., f.; 

 N.; La Sal Mts., West Mt. Peale) which I can hardly distinguish 

 from t^-pical S. nivalis, and which, in my opinion, form connecting 

 links between it and 5. saximontana Rydbg. I take this last 

 species, therefore, only for a variety of S. nivalis, from which it 

 chiefly differs by the characters given later. Rydberg himself 

 said (1899) that 5. nivalis "perhaps represents only the most de- 

 pauperate form" of his S. saximonta^ia, and he repeats in his Cat. 

 FL Mont. 112. 1900 that the latter "seems to grade into S. 

 nivalis," while such an accurate observer as Piper (in Contr. U.S. 

 Nat. Herb. 9:216. 1906) states that "vS. saximontana probably is 

 not specifically distinct from 5. nivalis.'^ 



4b. S. nivalis var. saximontana, nov. var. — S. reticulata Bebb 

 in Coulter, Man. Rocky Mt. Bot. 339. 1885, non L. ; Ball in Trans. 

 St. Louis Acad. Sci. 9:90. 1899. — S. saximontana Rydberg in Bull. 



