24 POACEAE. 



Flowering glumes over 5 mm. long, equally hairy throughout. 



Flowering glumes 5-6 mm. long, spindle-shaped when mature ; callus 



short. 7- S. viridula. 



Flowering glumes 6-7 mm. long, almost cylindric ; callus long and 



pointed. 8. 5. Nelsonii. 



Empty glumes firm, thickish, membranous or herbaceous ; nerves not promi- 

 nent. 

 Flowering glumes 4-5 mm. long ; leaf-blades very narrow, involute. 



9. S. minor. 

 Flowering glumes 8-10 mm. long; leaf-blades broad. 



Panicle slender; stem low and slender. 10. S. Scribneri. 



Panicle stout and dense; stem tall and stout. n. S. Vaseyi. 



1. Stipa neo-mexicana (Thurb.) Scribn. Dry hills from Colo, to N. Mex. 

 and Calif. Alt. up to 6000 ft. Colorado Springs. 



2. Stipa comata Trin. & Rupr. On dry plains and hills, especially in sandy 

 soil, from Alb. to Alaska, N. Mex. and Calif. Alt. 4000-8500 ft. Along the 

 Platte River, Denver; New Windsor, Weld Co.; Mancos ; Almeha; Ft. Col- 

 lins ; mesas opposite Grand Junction ; Rist Canon ; near Narrows along Pou- 

 dre River. 



3. Stipa Tweedyi Scribn. Plains and valleys from Alb. to Wash., Colo. 

 and Ariz. Alt. 5000-10,000 ft. Ft. Collins ; near Badito, between La Veta 

 and Gardner; Walsenburg; Arboles; Grayback mining camps; Black Canon 

 of the Gunnison ; Chester, Saguache Co. ; Durango ; Mancos ; North Park ; 

 Gypsum ; Rist Canon. 



4. Stipa spartea Trin. On prairies from Man. to B. C, Ills, and Colo. 

 Reported from Colorado Springs (Porter) ; South Park (Canby, Mehan) ; 

 but doubtful. 



5. Stipa Porteri Rydb. (S. Mongolica Porter & Coult. ; not Turcz.) 

 Mountains of Colo. Twin Lakes. 



6. Stipa Richardsonii Link. In meadow lands and hillsides from Alb. to 

 Mont., S. D. and Colo. Mountains west of Laramie River, Larimer Co. 



7. Stipa viridula Trin. (S. parviflora Americana Schultes) Dry prairies 

 and hills from Sask. to Mont., Kans. and Utah. Alt. 4000-8500 ft. Gato; 

 Columbine; plains, Larimer Co.; Rist Canon. 



8. Stipa Nelsonii Scribner. Dry plains and hills from Ass. to Ida. and 

 Colo. Alt. 7500-10,000 ft Near Boulder; hills about Box Canon, west of 

 Ouray; Cerro Summit; Idaho Springs; Poncha Pass; Georgetown; Durango; 

 West Mancos Canon ; Rist Canon ; Poudre Canon. 



9. Stipa minor (Vasey) Scribn. (S. viridula minor Vasey) Dry hill- 

 sides and mountain valleys from Mont, to Utah and N. M. Alt. 8000-12,500 

 ft North Park; Twin Lakes; Marshall Pass; Roger's; Cumbres ; Colorado 

 Springs; Robinson, Summit Co.; Long Gulch; near Chamber's Lake; Ute 

 Pass road; along the Michigan, North Park; Anita Peak, Routt Co. 



10. Stipa Scribneri Vasey. On foot-hills and mountain-sides of Colo, and 

 N. M. Alt. 5000-9500 ft Plains and foot-hills near Boulder; Trail Glen; 

 Clear Creek Canon, Golden ; near Empire ; Royal Gorge ; Georgetown. 



11. Stipa Vaseyi Scribn. (S. viridula robusta Vasey.) On foot-hills and 

 mountain-sides from Colo, to Ida., Tex. and N. M. ; also in Mex. Alt. 5000- 

 9000 ft Colorado Springs; New Windsor, Weld Co.; Idaho Springs; foot- 



