30 POACEAE. 



long, shining and often brownish-purple; glumes ciliate on the keels, the lower 

 short; lemma 5-6 mm. long, its awn divergent and about as long. A common 

 alpine grass occurring in the Blue Mountains at 1700 meters altitude. 



Trisetum cernuum Trin. Stems 60-100 cm. tall, erect, the nodes pale; 

 leaf blades flat, merely scabrous, 15-20 cm. long, 6-10 mm. wide; panicle 

 10-15 cm. long, loose, nodding; branches in distant whorls, capillary, cernuous, 

 flower-bearing above the middle; spikelets 2-4-flowered, 6-7 mm. long without 

 the awn; lemma 3-4 mm. long, bearing an awn about twice its length. Moist 

 woods and copses. 



Trisetum canescens Buckl. Much like T. cernuum, the leaf blades and 

 sheaths pubescent; nodes usually dark; panicle erect, 7-16 cm. long; lemma 

 7 mm. long. In coniferous woods. 



50. SPHENOPHOLIS. 



Panicles contracted ; spikelets 2-flowered ; the rachilla extend- 

 ing beyond the flowers; glumes shorter than the spikelet; the 

 lower linear, acute, 1-nerved; the uppei much broader, 3-nerv r ed, 

 obtuse or rounded at the apex, or sometimes acute, tht, margins 

 scarious; lemmas narrower, generally obtuse, 1-3-nerved, awn- 

 less; palea narrow, 2-nerved; grain free, loosely enclosed in the 

 scale and palea. 



Panicle dense, erect; lemma obtuse. S. obtusata. 



Panicle loose, usually nodding; lemma acutish. S. pallens. 



Sphenopholis obtusata lobata (Trin.) Scribn. Somewhat tufted, perennial, 

 60-100 cm. tall, the stems smooth; leaf blades flat, scabrous, 10-15 cm. long, 

 3-5 mm. wide; panicle erect, narrow, 5-12 cm. long, pale green, the branches 

 short and densely flowered; lemma narrowly obovate, obtuse. Rather rare, 

 on sandy bars of Snake River. 



Sphenopholis pallens major (Torr.) Scribn. Stems 30-90 cm. tall, gla- 

 brous; leaf blades 6-15 cm. long; panicle slender, 8-15 cm. long, usually loose 

 and nodding, the branches 3-7 cm. long; spikelets about 3 cm. long, usually 

 numerous; lemma narrow, acutish. Infrequent. 



51. KOELERIA. 



Tufted perennial grasses with narrow leaves and densely 

 flowered spike-like panicles; spikelets 2-4-flowered; rachilla 

 articulated between the lemmas; glumes acute, subequal, keeled, 

 scarious on the margins; lemmas 3-nerved, keeled, acute; palea 

 hyaline, acute; grain free, enclosed in tht lemma and palea. 



Koeleria cristata (L.) Pers. Perennial, the erect stems densely tufted, 

 30-70 cm. tall, usually glabrous; leaves narrow, commonly involute; panicle 

 dense, greenish or purplish, shining, 5-15 cm. long, often more or less inter- 

 rupted; spikelets 4-5 mm. long, 2-4-flowered. Common on dry hillsides. 



52. ERAGROSTIS. 



Annual or perennial grasses; inflorescence a contracted or 

 open panicle; spikelets many-flowered, more or less flattened; 



