24 MEMOIRS OF THE XEAV YORK BOTANICAL GARDEN. 



In wet meadows at an altitude of 2000 m, 



Yellowstone Park: East De Lacy's Creek, Aug. 10, 1897, 

 I^vdbcrg- d- Bcssey, Jjji. 



Stipa comata Trin. & Rupr. Mem. x\cad. St. Petersb. (VI.) 5: 75 

 [Man. R. M. 408; 111. Fl. i: 138: Bot. Cal. 2: 285]. 

 Common on prairies, plains and dr}' meadows, especially in sandy 



soil, up to an altitude of 2000 m. 



Montana: Dillon, July 3, 1895, C. L. Shear, JJ4 and T^ydd erg; 



2oy8; Manhattan, July 17, Shear, jjo and 4Jj : Rydberg, 2ig^; 



Spanish Basin, July 20, 1896, Flodman, yi ; Great Falls, 1887, R. 



S.Williams, 6oj : Bozeman, 1886, Tiveedy, ioij: Pony, July 6, 



1897, Rydberg cf- Bessey, JSJo: Spanish Basin, 1896, Rydberg; 



J 1^2 and 3136 ( ?) ; Lewis and Clarke Co., Mrs. E. Mnth; Flathead 



Region, 1883, H. B. Ayres: Smith River, 1883, Seribuer, jjy; 



Jefferson City, jjS. 



* Stipa Tweedyi Scribn. Bull. U. S. Dept. Agric. Div. Agrost. 11 : 



47 J Stipa coiuata intermedia Scribn. Bot. Gaz. ii : 171 ; not 



S. intermedia Trin. 



It very closely resembles S. comata, but the spikelets and awns are 

 much longer, and approaches S. spartea in size. At an altitude of 

 2000-2500 m. 



Yellowstone Park: Junction Butte, 1885, Tz-'ecdy, 610. 



Montana: Jefferson City, 1883, Scribner. 



Stipa spartea Trin. Mem. Acad. St. Petersb. (VI.) i : 82 [Man. R. 

 M. 408; 111. Fl. i: 139]. 



Rare, on prairies, not reaching an altitude of 1500 m. 

 Montana: Horned Creek, 1883, Seribner, j;^g. 



* Oryzopsis asperifolia Michx. Fl. Bor. Am. 1:51 [111. Fl. i : 140]. 



An eastern species characterized by the large spikelets, 6-8 mm. 

 long, and the long narrow leaves crowded at the base. In woods at 

 an altitude of 1000-2500 m. 



Montana: Flathead Valley, 1883, Canby, j^j. 



Yellowstone Park: Soda Butte Creek, 1885, Tzveedy, 61 j. 



* Oryzopsis exigua Thurb. Bot. U. S. Explor. Exped. 17: 481. 



It somewhat resembles the preceding, but the spikelets are smaller, 

 about 4 mm. long : it is still nearer related to the eastern O. juneea, 

 from which it differs in the more simple panicle, the less pubescent 



