182 Rydberg : Studies on- Rocky Mountain Flora 



lanceolate in outline and petioled ; the upper lanceolate or linear in 

 outline and sessile ; all deeply pinnatifid with narrow, oblong or 

 linear segments.: cymes contracted, corymbiform : heads 7-8 mm. 

 high ; bracts linear, acute, yellowish-green, and occasionally with 

 brownish tips, a little shorter than the disk ; calyculate ones 

 few, linear, small and crisp : rays pale yellow, about 6 mm. long 

 and 1.5 mm. wide, 4-nerved, or very often lacking : achenes hispid- 

 puberulent on the angles. 



Nearest related to the eastern 5. Balsamitac, but characterized 

 by its yellowish green color and a more contracted cyme. It 

 grows at an altitude of 2000-3000 m. [Plate 5, f 4.] 



Idaho: Beaver Canon, 1895, /?y<^(^^7'^ (type in the herbarium 

 of N. Y. Botanical Garden). 



Montana: Deer Lodge, 1895, Rydberg, 28^0 (rayless) ; 

 Helena, 1887, F. D. Kelscy, ^01. 



Wyoming: Buffalo Fork, 1897, Tivecdy, 3S6 ; Laramie Plains, 

 1889, E. L. Greene (rayless); Green River, 1894, Aven Nelson, 

 ioj6 (rayless). 



19. Senecio aurellus sp. nov. 



Perennial with a short rootstock, somewhat floccose when 

 young, soon glabrate : stem striate, 4-5 dm. high : basal leaves 

 spatulate or cuneate, dentate-serrate, about 5 cm. long, with a 

 short petiole, soon glabrous : lower stem leaves long-petioled, 

 cuneate or spatulate, lyrately lobed, the upper narrowly oblance- 

 olate and subsessile, slightly auricled at the base : cyme com- 

 pound but with rather few heads, which are about 8 mm. high : 

 bracts 12-16, glabrous, yellowish-green, lanceolate, thin ; caly- 

 culate ones minute, lanceolate : rays golden-yellow, 5-6 mm. 

 long and 2 mm. wide, 4-nerved : achenes scabrous hispidulous on 

 the angles. 



In the form of the stem leaves this most resembles, perhaps, 

 .S. rosidatiis, but these are thinner and perfectly green, only slightly 

 floccose when young. Otherwise it is intermediate between the 

 eastern 5". Balsamitae and .S". niultUobatus. The type was deter- 

 mined by Professor Greene as " S. psciuimireiis Rydb., not typical." 

 To that species it does not have any close relationship. [Plate 

 6, f 12, 12a.] 



Colorado: Mancos, 1898, Baker, Earle & Tracy, gg8 (type 

 in the herbarium of New York Botanical Garden). 



