38 POACEAE. 



Muhlenbergia racemosa (Michx.) BSP. Stems 30-90 cm. high, simple or 

 nearly so; panicle narrowly oblong, 5-8 cm. long, spike-like and usually inter- 

 rupted; glumes bristle-tipped; lemma very acute. 



Somas Prairie, 49° latitude, Lyall, and eastward. 



56. STIPA, 



Tufted grasses; inflorescence a panicle; spikelets 1-flowered, 

 narrow; floret with a bearded and pointed callus at base; lemma 

 1, indurated, bearing a twisted or bent awn which is articulated 

 at the base; grain narrow, free, tightly closed in the lemma. 



All in our limits are perennials. 



Awn 10-20 times as long as its lemma. S. comata. 

 Awn 4-7 times as long as its lemma. 



Callus ver>' short, obtuse; glumes 8-12 mm. long. S. lemmoni. 



Callus acute; glumes 6-8 mm. long. S. minor. 



Stipa comata Trin. & Rupr. Tufted, pale green, 40-80 cm. high; blades 

 involute; ligule 4-5 mm. long, conspicuous; panicle open, 20-30 cm. long, 

 often included at base, the branches spreading and few-flowered; glunies 5- 

 nerved, subequal, 15-25 mm. long; lemma 10-12 mm. long; awn 10-15 cm. 

 long. 



Vancouver Island, Macoun, and common cast of the Cascade Mountains. 



Stipa lemmoni Scribn. (5. columhiana Macoun.) Stems 60-90 cm. high; 

 leaf blades flat or involute, firm; sheaths smooth; ligule 1 mm. long; panicle 

 narrow with erect branches, 2-5 cm. long; glumes subequal, scarious, lanceolate, 

 acuminate, 8-12 mm. long; lemma short-pubescent, the body about 6 mm. long; 

 awn 15-20 mm. long, pubescent to the second bend. 



In dry ground, British Columbia to California. 



Stipa minor (Vasey) Scribn. Tufted, 50-100 cm. tall, dark green; leaf- 

 blades involute, long-attenuate, 10-30 cm. long, scabrous; sheaths shorter 

 than the internodes, loose, smooth; ligule very short ; panicle erect, rather dense, 

 8-20 cm. long, narrow, its base included in the uppermost sheath, the branches 

 mostly in pairs; spikelets 8-12 mm. long, purple-tinged; lemma sparsely 

 appressed-hairy, the awns 20-30 mm. long, bent near the middle, below which 

 they are pubescent. 



In dry ground, infrequent except in the interior. 



57. PHLEUM. 



Annuals or perennials; inflorescence a spike-like raceme; spike- 

 lets 1-flowered; glumes membranous, compressed, keeled, the 

 apex obliquely truncate, the mid-nerve produced into an awn; 

 lemma much shorter; grain ovoid, free, enclosed in the lemma 

 and palea. 



Spike-like racemes cylindric; aw'ns of glumes short. P. pratense. 



Spike-like racemes ovoid-oblong; awn as long as body of glume. P. alpinum. 



Phleum pratense L. Timothy. Tall, erect, 60-150 cm. tall; leaf blades 

 15-20 cm. long, 8-10 mm. wide, smooth or scabrous; spike-like raceme nar- 

 rowly cylindrical, erect, 5-15 cm. long; spikelets 2-5 mm. long; empty glumes 

 ciliate on the keels which are prolonged into awns 1 mm. long. 



Cultivated and running wild. 



