MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 445 



*Senecio Purshianus Nutt. Trans. Am. Phil. Soc. (II.) 7: 412; 



Senccio cauiis Gray, Syn. Fl. i" : 390, in part; not Hook. 



Lower than the preceding, the leaves all entire or the stem-leaves 

 somewhat dentate at the base ; tomentum denser ; heads much smaller 

 and bracts shorter-pointed. It is more common, growing at an alti- 

 tude of 2000-3000 m. 



Montana: Silver Bow Co., Mrs. Jennie Moore; Livingston, 

 1889, Tzveedy ; Cinnabar, 1887, j^^,* Helena, 1891, /ir<r/5^j/,- Black 

 Hawk, 1896, Flodman, go2 ; Little Belt Pass, goj ; Spanish Basin, 

 po^ and gos ; Bridger Mts., go6 ; Bozeman, 1895, Rydherg, 284^; 

 Bridger Mts., June 12-17, 1897, Rydberg & Bessey, S-5^ j Span- 

 ish Basin, June 23, S2jp; Livingston, 1883, Scr/bner, 121a; Jef- 

 erson River, 121b. 



Yellowstone Park: 1888, Dr. C/ias. H. Hall; Hood's Peak, 

 1897, P. Koch, 20. 



* Senecio Hallii Britton, Trans. N. Y. Acad. Sci. 9: 11. 



Like S. canns, but the whole plant densely white pannose-tomen- 

 tose, even the involucre. On the geyser formations, at an altitude of 

 2500 m. 



Yellowstone Park : 1889, Dr. Chas. H. Hall ; Upper Geyser 

 Basin, Aug. 6, 1897, Rydberg & Bessey, S~57- 



* Senecio Howellii Greene, Bull. Torr. Bot. Club, 8: 98. 



Like S. canus, but with narrow often lobed leaves linear in outline, 

 and much sparser pubescence. It grows on dry hills, up to an altitude 

 of 2500 m. 



Montana: Pony, July 7, 1897, Rydberg & Bessey, ^261 (a 

 doubtful specimen, with entire leaves, resembling those of S. 

 zuerncriaej'olia) . 



Yellowstone Park: iSSt,, Miss Maty Compton. 



* Senecio Plattensis Nutt. Trans. Am. Phil. Soc. (II.) 7: 413 [111. 



Fl. 3: 478]. 



Dr. Gray included this in S. aureus Balsamitae, but it is much 

 nearer related to the eastern S. tonientostis, as it is more or less 

 floccose when young and has hairy achenes. It has much more 

 divided leaves than S. tomentosus; they are lyrate, as in S. Bal- 

 samitae, but much thicker. It is a typical prairie species, seldom 

 extending to an altitude of more than 1000 m. 



Montana: Custer Co., 1892, Mrs. Light. 



