40 1 ] FLORA OF BOULDER, COLORADO 253 



Common in the mountainous region, 7000-10000 ft. (Dan- 

 iels, 629), Also at Ward (Rydberg). 



North Dakota to Montana ; New Mexico to Arizona. 



1 182. S. Riddellii T. & G. [S. fihfolins Fremontii T. & G.]. 

 Riddell's groundsel. 



Frequent on the plains about Boulder, 5100-6000 ft. (Dan- 

 iels, 481). 



Nebraska to Colorado ; Texas to New Mexico. 



1 183. S. multicapitatus Rydb. Many-headed groundsel. 

 Plains about Boulder, 5600 ft. (Daniels, 401). 

 Colorado to New Mexico and Arizona. 



1 1 84. S. spartioides T. & G. Broom-like groundsel. 

 Along Boulder Canon road, 5500 ft. (Daniels, 804). Also 



mountains between Sunshine and Ward (Rydberg). 

 Nebraska to Wyoming; Texas to Arizona. 



475. CmSITJM Hill. Thistle. 



1 185. C. Parryi (Gray), Cockerell. Nov. comb. [Cnicus Par- 

 ryi- Gray; Carduiis Parryi (Gray) Greene]. Parry's 

 thistle. 



Boulder (Rydberg). 



Colorado to New Mexico and Utah. 



1 186. C. scopulonim (Greene) Cockerell. Nov. comb. [Cni- 

 cus eriocephalus Gray ; Carduus scopulonim Greene] . 

 Crag thistle. 



Arapahoe Peak above timberline, 10500-12000 ft. (Daniels, 

 887). Also at Ward (Rydberg). 

 Colorado. 



1187. C. griseum (Rydb.) Cockerell. Nov. comb. [Carduus 

 griseus Rydb.]. Gray thistle. 



Ward (Rydberg). 

 Colorado. 



1 188. C. Americanum (Gray), Daniels. Nov. comb. [Cnicus 

 Amcricanus Gray ; Carduus Centaureae Rydb. ; Cirsium 



