MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 23 



Shear, 4.1 J ; Elk Mts., near Castle, Aug. i, 1896, Flodinan, 7^; 

 Spanish Basin, July 18, yy : Great Falls, 18S7, R. S. Williams, 

 602; Indian Creek, July 21, 1897, Rydbcrg- ct Bcsscy, jj^2 ; Elk 

 Mts., i8g6, Ryddcrg-, J2S1 : Bozeman, 1896, jo//; Spanish Basin, 

 Jijj; Castle, J2j8; Elk Mts., Jjoy: Little Belt :\Its., J277 and 

 3422; Bull Mts., 1883, Canhy : Smith River, 1883, Scrihner, j^o, 

 in part. 



Yellowstone Park: 1S84, Tzi'cedy, 262 ; Swan Creek, 1885, 

 6og; Agate Creek, 613: East De Lacy's Creek, Aug. 10, 1897, 

 Rydhcrg & Bessty, Jjjia. 



* Stipa Lettermani Vasey, Bull. Terr. Bot. Club, 13 : 53 : Stipa vir- 



idnla Letteriiuini Vo.sey, Cont. U. S. Nat. Herb. 3: 50. 

 Like S. vlridiila but more slender, with smaller flowers and short 

 awn. Dry hills at an altitude of 2000 m. 



Montana: Lima, Aug. 5, 1895, Shear, jpj : Rydderg; 2J02. 

 Idaho: Beaver Canon, Aug. 7, 1895, Rydherg; 2J4J. 



* Stipa Vaseyi Scribner, Bull. U. S. Dept. Agric. Div. Agrost. 11 : 



46 ; Stipa robust a (V^asey) Scribner, Bull. U. S. Dept. Agric. Div. 



Agrost. 5 : 23 : not Nutt. : Stipa viridula robusta Vasey, Cont. 



U. S. Nat. Herb. 3: 50. 



Resembles S. viridula in habit, but is a much larger plant, 16- 

 20 dm. high. It has been reported from ]Montana. I have not seen 

 any specimens from the state, but the following were collected just 

 across the border. 



Idaho: Beaver Caiion, June 27, Shear, joi ; Aug. 7, Rydberg, 

 2345- 



* Stipa Williamsii Scribner, Bull. U. S. Dept. Agric. Div. Agrost. 



II : 45. 1898. 



It is distinguished from S. viridula by the hairy culm and sheaths 

 and its longer and more acute callus. In dry soil at an altitude of 

 about 2000 m. 



Montana: Jefferson City, 1883, Seribner, 34.0, in part. 



* Stipa Elmeri Piper «& Brodie ; Scribner, Bull. U. S. Dept. Agric. 



Div. Agrost. 11: 46, 1898; Stipa viridula pubescens Vasey, 

 Cont. U. S. Nat. Herb. 3 : 50 ; not S. pubescens R. Br. 

 Distinguished from S. viridula, which it resembles, by the hairy 



culm and sheaths, and by the awns, which are pubescent to the second 



joint. 



