POACEAE. 29 



Alt. 6000-12,000 ft— Near Pagosa Peak; Ruxton Park; Mount Ouray; Mon- 

 tezuma ; Ruxton Dell ; Ribbon Lake ; South Park ; Colorado Springs ; Minne- 

 haha; Hinsdale Co.; Middle Park; southeast of Jefferson, South Park; 

 Pagosa Peak. 



26. SPOROBOLUS R. Br. Dropseed, Poverty-grass, Wire-grass. 



Perennials. 



First glume one-half as long as the second or less ; plant not with long, scaly 

 root-stocks. 

 Branches of the panicle verticillate. i. 5". argutus. 



Branches of the panicle scattered. 



Spikelets about 2 mm. long; first glume lanceolate. 



Sheath naked or sparingly ciliate at the throat; empty glumes glabrous. 



2. S. air aides. 

 Sheath with a conspicuous tuft of hairs at the throat ; empty glumes 



scabrous on the keel. 

 Leaf-blades 6 cm. long or less, widely spreading, involute ; sheath 

 pubescent with long hairs, at least towards the base. 



3. 5. Nealeyi. 

 Leaf-blades not widely spreading; sheaths glabrous, except the apex, 



and slightly on the margins. 

 Panicle usually more or less included in the sheaths ; its lower 



branches much exceeding the upper ones. 4. 5. cryptandrus. 

 Panicle always exserted, oblong, comparatively narrow ; its lower 



branches but little, if any, exceeding the upper ones. 



5. 5. Aexuosus. 

 Spikelets 4.S-5 mm. long ; first glume subulate, usually awned. 



6. 5'. heterolepis. 

 First glume almost equalling the second ; plants with long, scaly root-stocks. 



7. 5". asperifolius. 

 Annuals ; empty glumes almost equal, ovate. 8. S. confusus. 



1. Sporobolus argutus (Nees) Kunth. On the plains from Kan. to Colo., 

 Tex. and Mex. ; also West Indies. — Exact locality not given (Vasey). 



■A. Sporobolus airoides Torr. Dry prairies and river-valleys from Neb. to 

 Tex. and Calif. — Alt. 4000-11,000 ft. — Cation City; Marshall Pass; South 

 Park; Mancos; Fort Collins; Doyles; Arboles; Colorado Springs; La Porte; 

 Palisade, Mesa Co. ; Grand Junction ; Alamosa ; Cottonwood Creek ; Gun- 

 nison. 



3. Sporobolus Nealleyi Vasey. In dry places from Tex. to Colo, and N. 

 M. — Alt. about 7500 ft. — Vicinity of Alamosa. 



4. Sporobolus cryptandrus (Torr.) Gray. In sandy soil from Mass. to 

 Wash., Pa., Tex., Ariz, and Ore. — Alt. 4000-8000 ft. — Caiion City; Empire; 

 Manitou; Denver; Deer Run; plains and foot-hills, near Boulder; Colorado 

 Springs ; Fort Collins ; Salida, Chaffee Co. ; La Veta ; Georgetown ; Spring 

 Canon; Poudre Cafion; gulch, west of Soldier Caiion. 



5. Sporobolus flexuosus (Thurber) Rydb. (5". cryptandrus Aexuosus Thur- 

 ber.) In sandy places from Tex. to Nev. and Mex. — ^Reported from Colo- 

 rado, but doubtful. 



6. Sporobolus heterolepis A. Gray. On dry prairies from Que. to Sask., 

 Pa. and Colo. — Exact locality not given. 



7. Sporobolus asperifolius (Nees & Mey.) Thurber. On dry prairies from 

 Ass. to B. C, Mo., Tex. and Calif. — Alt. 4000-7500 ft— Cottonwood Creek; 



