180 Rydberg : Studies ox Rocky Mountain Flora 



lanceolate, acute, shorter than the disk : rays 4-5 mm. long and 

 1.5 wide, 4-nerved : achenes striate, glabrous. 



This species is nearest related to S. cymbalarioides but is taller, 

 with narrower basal leaves, which have sharper teeth ; the heads 

 are also much more numerous. It grows at an altitude of 2000- 

 2500 m. Baker, Earle and Tracy's specimens were labeled by 

 Prof. Greene Scnecio Fcndleri, approaching S. couipactiis. This is 

 strange from one that claims that he has known ^. Fendlcri since 

 1870.* This plant has little in common with that species or with 

 5. Nelsonii Rydb. [Plate 5, f. 6.] 



Colorado : Grizzly Creek, 1896, C. F. Baker (type in the 

 herbarium of N. Y. Botanical Garden); Lake City, 1878. H. IV. 

 Pease (depauperate) ; Mancos, 1898, Baker, Earle & Tracy, 6j. 



15. Senecio acutidens sp. no v. 



Perennial, with a thick woody rootstock and short caudex, in 

 age glabrate or slightly floccose at the base of the leaves : stems 

 several, about 2 dm. high, angled, more or less tinged with red : 

 basal leaves about 5 cm. long, thick, fleshy and somewhat glau- 

 cous, obovate or spatulate : sharply dentate above the middle, at 

 the base entire and abruptly contracted into a slender petiole : 

 lower stem leaves similar or oblanceolate and acute ; the upper 

 reduced, linear, laciniate-dentate or somewhat pinnatifid : cymes 

 corymbiforni and rather dense: heads 8-10 mm. high: bracts 

 broadly linear, acute, 7^ or ^ as long as the disk : rays about 

 5 mm. long and 1.5 mm. wide, 3-4-nerved : achenes slightly an- 

 gled, glabrous. 



Nearest related to ^. cymbalarioides but the leaves are thicker, 

 more glaucous and very acutely dentate. The perennial rootstock 

 and caudex are also thicker and more woody. [Plate 5, f 2.] 



Wyoming : Union Pass, 1 894, Aven Nelson, 8j8 (type in the 

 herbarium of N. Y. Botanical Garden). 



16. Senecio pseudaureus Rydberg, Bull. Torr. Club, 24: 298. 



1897 



This is nearest related to the eastern 5. aureus and has the 

 same subcordate, thin, basal leaves, but these are distinctly serrate, 

 instead of crenate. It is the most common species of the group 

 in the Rockies, growing in wet meadows at an altitude of looo- 

 3000 m. [Plate 5, f 10.] 



* See Pittonia, 4: 112. 



