134 



POACEAE 



16. Stipa nelsoni Scribn 

 Nelson's Stipa 



Fig. 289. 



Stipa nelsoni Scribn. U. S. Dept. Agr. Div. Agrost. Bull. 11: 

 46. 1898. 



Cnlms 1-1.5 meters tall, smooth; blades flat, 15-30 

 cm. long, 3-5 mm. wide ; panicle narrow, 20-25 cm. 

 long, rather densely flowered ; glumes acuminate, 

 nearly equal, about 12 mm. long ; lemma about 7 mm. 

 long; awn 4-5 cm. long. 



Open ground, Arid Transition Zone; eastern Washington 

 and Oregon to Wyoming. June-Aug. Type locality: Wyo- 

 ming. 



17. Stipa minor (Vasey) Scribn. 

 Subalpine Stipa. Fig. 290. 



Stipa viridula minor Vasey, Contr. U. S. Nat. Herb. 3: 50. 

 1892. 



Stipa minor Scribn. U. S. Dept. Agr. Div. Agrost. Bull. 11: 

 46. 1898. 



Culms few in a cluster, 50-80 cm. tall ; sheaths 

 smooth; ligule very short; blades flat or becoming 

 involute, narrow, as much as 30 cm. long; panicle 

 narrow, 15-20 cm. long; glumes 6 mm. long, 3-nerved, 

 slightly scabrous on the keels ; lemma narrow, pilose, 

 5 mm. long; awn about 12 mm. long, nearly smooth, 

 twice-geniculate, the first section 3 mm. long. 



Open ground. Arid Transition and Canadian Zones; Wash- 

 ington, to the high Sierra Nevada Mountains of central Cali- 

 fornia, and east to Wyoming and Colorado. July-Aug. Type 

 locality: Colorado. 



Stipa littoralis Phil, and Nassella chilensis Desv., Chilean 

 perennials, have been found on ballast at Linnton, Oregon 

 {Nelson). 



18. ORYZOPSIS Michx. Fl. Bor. Am. 1: 51. pi. 9. 



1803. 



Spikelets 1-flowered, disarticulating above the glumes; glumes about equal, obtuse or 



acuminate; lemma indurate, usually about as long as the glumes, broad, oval or oblong, nearly 



terete, usually pubescent, with a short blunt oblique callus, and a short deciduous sometimes 



bent and twisted awn ; palea inclosed by the edges of the lemma. Perennial mostly low 



grasses with flat or often involute blades, and terminal narrow or open panicles. [Greek, 



Oryza-like.] 



Species about 20 in the north temperate regions of both hemispheres. Type species, Ovyzopsis asperi- 

 jolia Michx. 



Lemma smooth. 



Blades flat, 5 mm. wide or more; spikelets numerous, 3 mm. long. 

 Blades involute, less than 2 mm. wide; spikelets few, 5 mm. long. 

 Lemma pubescent. 



Pubescence short and appressed. 



Branches of panicle stiffly erect; awn about 5 mm. long, sometimes less; blades stiffly erect. 



3. O. cxiyua. 

 Branches of panicle slender, ascending, somewhat flexuous; awn more than 5 mm. long; blades 

 slender and flexuous. 4. O. kingii. 



Pubescence long and silky. 



Branches of panicle and pedicels divaricately spreading. 5. O. hymcnoides. 



Branches of panicle and pedicels erect or ascending. 



Awn 6 mm. long; culms usually less than 30 cm. tall. 6. O. webbcri. 



Awn 12 mm. long; culms 30-60 cm. tall. 7. O. bloomi>ri 



1. O. miliacea. 



2. O. hendcrsoni. 



