38 POACEAE. 



50. TRIDENS R. & S. 



Second empty glume i-nerved. i. T. muticus. 



Second empty glume 3-s-nerved. 2. T. elongates. 



i. Tridens muticus (Torr.) Nash. (Triodia mutica Benth.) On dry hills 

 from Tex. to Colo, and Ariz.; also northern Mex. Canon City (Porter}. 



z. Tridens elongatus (Buckley) Nash. On plains and prairies from Tex. 

 to Colo, and Ariz. Alt. about 5500 ft. Pueblo; Canon City. 



51. DIPLACHNE Beauv. 



i. Diplachne acuminata Nash. In wet places from Ark. to Neb. and Colo. 

 Alt. 4000-5500 ft. New Windsor, Weld Co. ; Canon City. 



52. REDFIELDIA Vasey. 



i. Redfieldia flexuosa (Thurb.) Vasey. (Graphcphorum fle.vuosum Thurb.) 

 In sand-hills from S. D. to Ind. Terr, and Tex. Alt. 4000-5500 ft. Sterling, 

 Logan Co. ; Fort Garland. 



53. KOELERIA Pers. PRAIRIE-GRASS, JUNE-GRASS. 



i. Koeleria cristata (L.) Pers. On prairies and plains from Ont. to B. C, 

 Pa. and Calif. A very variable species and perhaps a composite one. The 

 form common in the Rocky Mountain region has narrow, involute, glabrous 

 or puberulent leaves and narrow panicle, and has been described under the 

 name K. nitida Nutt. Alt. 4000-10,000 ft. Middle Park; Pagosa Springs; 

 vicinity of Boulder; foot-hills, Larimer Co.; Arboles; Gunnison; Sangre de 

 Cristo Creek; Golden; Twin Lakes; Mancos; Crystal Park; Minnehaha; 

 Cimarron ; vicinity of Ouray; near Pike's Peak; Stove Prairie Hill, Larimer 

 Co.; La Veta; Manitou ; North Park; Happy Hollow; Hotchkiss; Horse- 

 tooth Gulch ; Table Rock ; Manitou Junction ; Dixon Canon ; hills about 

 Dolores ; dry hills along Trail Creek ; Como ; Grizzly Creek ; Fort Collins ; 

 Hardin's ranch ; Willow Creek, Routt Co. 



54. ERAGROSTIS Beauv. SKUNK-GRASS, STINK-GRASS. 



Culm often decumbent at the base, much branched, 1-5 dm. high ; annuals ; 



panicle green. 

 Spikelets 1.5 mm. or less wide ; palet remaining attached to the continuous 



rachis, after the flowering glume has fallen. i. E. Purshii. 



Spikelets 2.5-5 mm. wide ; palet falling with the flowering glume and the inter- 

 nodes of the rachis. 2. E. major. 

 Culm erect, rigid, simple ; perennial ; panicle purple. 3. E. pectinacea. 



1. Eragrostis Purshii Schrad. In dry or sandy places from Ont. to Wash., 

 Fla. and Calif. Alt. 4000-7500 ft. Alamosa, Conejos Co.; Canon City, Fre- 

 mont Co. ; along the river, Ft. Collins. 



2. Eragrostis major Host. (E. poacoidcs megastachya A. Gray.) Natural- 

 ized from Europe, in waste places and fields from Ont. to Wash., Fla. and 

 Calif. Alt. 4000-6000 ft. Vicinity of Boulder; Longmont; New Windsor, 

 Weld Co. ; Canon City, Fremont Co. ; Cheyenne Mountain ; Tobe Miller's 

 ranch ; near Ft. Collins. 



