1919] SCHNEIDER— AMERICAN WILLOWS 55 



Rocky Mt. Bot. 131. 1909.— This delicate suffruticose species is 

 only known from the type locality, Electric Peak, in the northeast 

 corner of Yellowstone Park (Ig. Rydberg and Bessey, August 18, 

 1897, f.; N.) and from Sheep Mountain in the Teton Forest 

 Reserve, Wyoming (F. Tweedy, no. 292, fr.; N.)- Rydberg calls it 

 "the smallest willow in existence," but there are similar minims 

 among the European (5. ser pyllifolia Scop.) and Himalayan species 

 (5. oreophila var. secta And.) ; see Schneider in Sargent, PI. Wils. 

 3:146. 1916. The systematic position of 5. Dodgeana is not yet 

 quite understood; it seems to represent a rather singular type 

 among its American congeners. As to a doubtful pubescent variety^ 

 see my remarks under the following species. 



12. S. cascadensis Cockerell in Muhlenb. 3:9. 1907; Rydberg, 

 Fl. Rocky Mts. 198. 191 7.-5. tenera And. in DC, Prodr. 16^:288. 

 1868, non A. Braun (1850); Rydberg in Bull. N.Y. Bot. Gard. 

 1:269. 1901; Piper in Contr. U.S.N. Herb. 11:216 (Fl. State 

 Wash.). 1906; Ball in Coult. and Nels., New Man. Rocky Mt. Bot. 

 136. 1909; in Piper and Beattie, Fl. Northwest Coast 117. 1915;. 

 Jepson, Fl. CaUf. 344. 1909, pro parte. — S. phlebophylla Watson 

 in U.S. Geol. Sur. Expl. 40th parallel King's Rep. 5: Bot. 326. 1871,. 

 pro parte, non And. — S. arctica var. petraea Bebb in Watson, Bot. 

 Cahf. 2:90. 1879, pro parte, non And.; Ball in Trans. Acad. St. 

 Louis 9:89. 1899, pro parte. — S. Brownii var. petraea Bebb in Bot. 

 Gaz. 16:107. 1891, pro parte." — S. Brownii var. tenera Jones, The 

 Willow Fam. 19. 1908. — This species has always been regarded as 

 most closely related to S. petrophila, and Ball (1899) mentioned it 

 in the synon^Tny only as "a narrow-leaved form," while he (1909) 

 says "perhaps only a variety of the preceding" (5. petrophila). 

 By a close study of the material before me I have the impression, 

 however, that it possibly might have a more intimate affinity to 

 S. phlebophylla. Both Ball and Rydberg distinguish S. casca- 

 densis from S. petrophila only by the smaller size of the leaves and 

 the few-flowered aments, and neither author mentions the fact that 

 the old leaves are more or less persistent, a character not observed 

 by me in S. petrophila. The leaves of S. cascadensis are occasionally 

 up to 18 mm. long, and in male specimens, hke no. 1074 of Merrill 

 and Wilcox from the Teton Mountains, Wyoming, the catkins bear 



