450 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 



*Carduus Hallii (Gray) Heller, Cat. N. Am. PI. 7 ; Cnicus Hallii 

 Gray, Proc. Am. Acad. 19: 56 [Syn. Fl. i^ : 399]. 

 A glabrate species, with slender stem, and solitary pedunculate 



heads which are more or less leafy bracted at the base, the bracts 



tapering into an almost innocuous tip. 



Montana: Gallatin Co., 1886, Tzveedy, 11 28. 



Carduus scariosus (Nutt.) Heller, Cat. N. Am. PI. 7; Cirsium 

 scariosum Nutt. Trans. Am. Phil. Soc. (n.)7: 420; Cnicus scari- 

 osus Gray, Syn. Fl. i" : 402 [Man. R. M, 213]. 

 In meadows, at an altitude of 2000-2500 m. 

 Montana: Park Co., 1887, Tweedy 348 ; Forks of the Madison, 



July 26, 1897, Rydbcrg d- Bessey, 521 j: Madison River, 1883, 



Sc?'ibncr, I24d. 



Yellowstone Park: 1884, Tweedy, 184.; Lone Star Geyser 



Basin, Aug. 7, 1897, Rydberg & Bessey, 521S (a nearly acaulescent 



form). 



* Carduus canovirens. 



Stem 6-10 dm. high, grayish or yellowish green, striate, more or 

 less woolly, very leafy; leaves about 2 dm. long, grayish green, 

 slightly woolly on both sides or glabrate in age, the lower petioled, 

 the upper more or less decurrent, deeply divided, the lobes cleft 

 and toothed, tipped with moderately strong spines ; heads rather 

 numerous, terminating the branches, 2-3 cm. high ; bracts imbri- 

 cated, the outer much shorter than the inner, all more or less woolly 

 on the margin, and with a broad glandular ridge and a moderately 

 strong spine ; corollas straw-color. 



Belongs to the undulatus group, but has the habit of C Eatonii. 

 The forms of the leaves, the pubescence, and the size and form of 

 the heads are the same in the two ; but C. canovirens lacks the 

 cobwebby hairiness often found on the heads of C. Eatonii, and has 

 broader bracts with a very broad glandular ridge. It grows in 

 meadows, ai an altitude of 1800-2200 m. 



Montana: Jack Creek, July 15, 1897, Rydberg & Bessey, 52 1^ 

 (type). 



Utah: Logan, 1895, Rydberg. 

 Carduus undulatus Nutt. Gen. 2: 130 [111. Fl. 3: 486]; Cnicus 

 undulatus Gray, Proc. Am. Acad. 10 : 42 [Syn. Fl. i" : 403 ; Bot. 



Cal. i: 418; Man. R. M. 214]. 



On plains, prairies and hills, up to an altitude of 2000 m. 



Montana: Litde Rocky Mts., 1889, V. Havard; Helena, 1892, 

 F. D. Kelsey ; Lewis and Clarke Co., Mrs. Muth; Bozeman, 1892, 



