POACEAE. 55 



15. Agropyron Palmeri (S. & S.). (-^- spicatum Palmcri S. & S.) In 

 the mountains of Colo., N. M. and Ariz. Alt. up to 7000 ft. 'Mancos; Ar- 

 boles; Quimby. 



1 6. Agropyron Bakeri E. Nelson. Mountains of southern Colo. Alt. 9000 

 ft. Near Pagosa Peak. 



67. HORDEUM L. BARLEY, SQUIRREL-TAIL. 



Empty glumes all alike, subulate-filiform. 



Empty glumes 3-6 cm. long ; flowering glume of lateral spikelets long-awned. 



i. H. jubatum. 

 Empty glumes 1-2 cm. long ; flowering glume of lateral spikelets short-awned 



or awn-pointed. 



Lateral spikelets flower-bearing. 2. H. boreale. 



Lateral spikelets neutral. 3. H. nodosum. 



Empty glumes of the middle spikelet lanceolate. 4. H. pusillum. 



1. Hordeum jubatum L. On prairies and in meadows from Lab. to Alaska, 

 N. J., Tex. and Calif. Alt. 4000-11,000 ft. Mancos; Cerro Summit; Ar- 

 boles; vicinity of Boulder; Fort Collins; Fort Morgan; Golden; New Wind- 1 

 sor ; Alpine Tunnel ; Ute Pass ; Twin Lakes. 



2. Hordeum boreale S. & S. In meadows from Mont, to Alaska, Colo, 

 and Wash. Alt. up to 10,000 ft. Marshall Pass ; South Park ; Como ; North 

 Park. 



3. Hordeum nodosum L. In meadows from Mont, to Alaska, Tex. and 

 Calif. Alt. 5000-9500 ft. Georgetown; North Park; South Park; Durango; 

 Golden ; Twin Lakes ; Ft. Collins ; Chamber's Lake. 



4. Hordeum pusillum Nutt. In arid valleys from 111. to Ida., Ga. and Ariz. 

 Alt. 4000-6000 ft. Foot-hills, Larimer Co. ; New Windsor, Weld Co. ; near 

 the river, east of Ft. Collins ; Buckhorn Creek, Larimer Co. 



68. SITANION Raf. 



Some of the empty glumes 2-cleft ; lowest flower of one or both spikelets sterile 

 and like the empty glumes, but inserted on a rachilla and falling away 

 with it. 

 Sterile shoots numerous ; stem slender ; flowering glume 3-awned. 



i. 5". Hystrix. 



Sterile shoots few; stem stout; flowering glume i-awned. 2. S. molle. 

 Empty glumes all entire ; lowest flower of both spikelets perfect. 

 Flowering glumes glabrous. 



Stem-leaves very long, erect, flexuose, strongly involute. 3. 5. longi folium. 

 Stem-leaves short, rigid, spreading or divaricate. 4. 5". brevifolium. 



Flowering glumes soft-pubescent. 5. S. pubiflorum. 



1. Sitanion Hystrix (Nutt.) Smith. (Ageliops Hystrix Nutt.) On dry 

 shale hills and among sage brush on the plains from Wyo. to Wash, and 

 Colo. Walsenburg; North Park. 



2. Sitanion molle J. G. Smith. On moist mountain-sides in Colo. Alt. 

 10,500 ft. East side Buffalo Pass, Larimer Co. 



3. Sitanion longifolium J. G. Smith. On hillsides and among rocks from 

 Nebr. to Nev., Tex. and Ariz. Alt. 6500-9000 ft. Villa Grove, Saguache 

 Co.; Denver; Mancos; North Park; mountains of Larimer Co.; Hardin's 

 ranch ; Oak Mesa, Delta Co. ; Anita Peak, Routt Co. 



