POACEAE. 25 



hills, Larimer Co.; Pagosa Springs; Manitou; Twin Lakes; Hardin's ranch; 

 Soldier Caiion; gulch west of Soldier Canon; hills west of Dixon Canon. 

 12. Stipa Lettermannii Vasey. Hills and plains from Wyo. and Ida. to 

 Colo, and Utah. — Manitou. 



i8. ORYZOPSIS Michx. Mountain Rice. 



Spikelets, exclusive of awn, 2.5-4 "irn. long ; leaves very slender and involute. 

 Outer glumes 3-5 mm. long; inflorescence very narrow with short, erect 



branches. i. 0. exigua. 



Outer glumes 2.5 mm. long; inflorescence at length open with long, often 

 spreading or reflexed branches. 2. O. micrantha. 



Spikelets, exclusive of the awn, 6-8 mm. long ; leaves broad and often flat. 



3. O. asperifolia. 



1. Oryzopsis exigua Thurber. On hillsides from Mont, to Wash., Colo. 

 and Ore. — Alt. about 8500 ft. — Pearl. 



2. Oryzopsis micrantha (Trin. & Rup.) Thurber. On hillsides and among 

 bushes, from Ass. to Mont., Neb., N. M. and Ariz. — Alt. 4000-8500 ft. — Estes 

 Park; near Badito, between La Veta and Gardner; Georgetown; Arboles; 

 Idaho Springs; Durango; Glen Eyrie; Walsenburg; Roaring Fork, Larimer 

 Co. 



3. Oryzopsis asperifolia Michx. In woods from N. Sc. to B. C, Pa. and 

 N. M.— Alt. up to 9000 ft.— Veta Pass. 



19. ERIOCOMA Nutt. 



Panicle open, dichotomously branched with divergent branches, i. O. cuspidata. 

 Panicle narrow, with few spikelets on short, erect branches. n. 0. Webberi. 



1. Eriocoma cuspidata Nutt. {Oryzopsis cuspidata Benth.) On dry bar- 

 ren plains, canons and sand-hills from Sask. to Wash., Tex. and Calif. ; also 

 Mex. — Alt. 4000-9500 ft. — Grand Junction; Black Cation; Buena Vista; New 

 Windsor, Weld Co. ; Arboles ; Pueblo ; Fort Collins ; Mancos ; along Platte 

 River, Denver; Sangre de Cristo Creek; river bluffs north of La Veta; Wal- 

 senburg; Howe's Gulch; Cherokee Hill; hills about Trinidad; Dixon Caiion; 

 near Fork's Hotel, Manitou; Middle Park. 



2. Eriocoma Webberi Thurber. On desert lands from western Colo, to 

 Nev. and Calif. — Alt. up to 5500 ft. — Grand Junction. 



20. MUHLENBERGIA Schreb. 



Panicle contracted, narrow, spike-like, the short branches rarely spreading. 

 Empty glumes awl-shaped ; leafy and branched plants, with long root-stocks 

 covered by imbricated scales. 

 Flowering glumes not awned, basal hairs not equalling the flowering glume. 

 Empty glumes about equalling the flowering glume in length, sharp-pointed, 

 about 3 mm. long. i. M. mexicana. ■ 



Empty glumes exceeding the flowering glume, generally twice as long, 

 awned, about 5 mm. long. 2. M. racemosa. 



Flowering glumes distinctly awned ; basal hairs equalling the flowering 

 glume. 3. M. comata. 



Empty glumes lanceolate to ovate ; plants mostly tufted and leafy at the base, 

 only in M. Richardsonis with an elongated, scaly root-stock. 



