GRASS FAMILY 109 



row, firm ; panicle 3 to 6 inches long, the branches slender, rather stiffly ascend- 

 ing, the longer 2 to 3 inches long, bearing spikelets from about the middle; 

 glumes comparatively broad, indistinctly 3 to 5-nerved, smooth, rather 

 abruptly acuminate, equal, 4 to 5 lines long; lemma elliptical, 2% lines long, 

 densely long-villous ; awn about l /2 inch long, tardily deciduous, once-genicu- 

 late, the first section about 3 lines long, slightly twisted, appressed-villous, 

 indistinctly bent or flexuous, the second section straight, minutely scabrous. 



Dry regions, Washington to Manitoba- and south to New Mexico. 



Locs. Moulton, Modoc Co., Griffiths <$ Hunter 456; Mt. Diablo, Bolander ; Lancaster, 

 Elmer 4165. 



Eefs. OBYZOPSIS BLOOMERI Bicker; Piper, Contr. Nat. Herb. 11: 109. 1906. Stipa 

 bloomeri Boland. Proc. Cal. Acad. 4: 168. 1872, type from Mono Pass, Bolander 6116. S. 

 siberica [Lam. misapplied by] Thurb. in Wats. Bot. Cal. 2: 287. 1880. 



16. MUHLENBERGIA Schreb. 



Spikelets 1-flowered. Glumes thin, 1-nerved, often aristate. Lemma with a 

 short, often barbate callus, narrow, membranaceous, 3-nerved, acute, mucron- 

 ate. or often awned from the tip or from between the teeth of the bidentate 

 apex. Palea thin, about as long as lemma. Annual or usually perennial 

 grasses, the inflorescence varying from an open and diffuse, to a narrow and 

 spike-like panicle. Species about 60, mostly American, especially abundant 

 on the Mexican plateau. (Rev. Dr. Henry Muhlenberg. a distinguished Ameri- 

 can botanist, 1753 1815.) 

 Hairs at base of floret at least half as long as body of lemma; panicle narrow; perennials. 



Hairs at base of floret copious, as long as body of lemma 1. M. comata. 



Hairs at base of floret not over y 2 as long as body of lemma. 



Panicle loose; upper glume 3-toothed; blades involute 2. M. gracilis. 



Panicle close; glumes entire; blades flat. 



Blades narrow, about 1 line wide 3. M. lemmoni, 



Blades broad, iy 2 to 2~y 2 lines wide 4. M. calif 'arnica. 



Hairs at base of floret minute or wanting. 



Glumes erose-toothed ; culms erect; plants perennial, without rhizomes 7. M. jonesii. 



Glumes entire; culms mostly decumbent or spreading; plants perennial with rhizomes, or 



annual. 

 Lemma awned, the awn 3 lines long or more. 



Plants annual; panicle narrow; awn 5 to 7 lines long 5. M. microsperma. 



Plants perennial; panicle diffusely spreading; awn 3 lines long 6. M. porteri. 



Lemma unawned, mucronate; panicles narrow. 



Culms capillary; plants lax and soft, no creeping rootstoeks, often annual; blades 



flat 8. M . filiformis. 



Culms stouter, rather woody or wiry; rootstoeks creeping; blades involute. 



Plants widely spreading or creeping; glumes % line long 9. M. repens. 



Plants erect or decumbent at base; glumes % line long 10. M. squarrosa. 



1. M. comata Thurb. Perennial, with numerous scaly rhizomes ; culms erect 

 or sometimes spreading, smooth below, scabrous above, pubescent about the 

 nodes, 1 1 / 2 to 3 feet high ; sheaths smooth or slightly scabrous, keeled ; ligule 

 1/2 line long, membranaceous, short-ciliate ; blades flat, 1 to 3 lines wide, sca- 

 brous; panicles narrow, spike-like, usually more or less lobed or interrupted, 

 often purple-tinged, 3 to 6 inches long; glumes narrow, acuminate, 1-nerved, 

 smooth, ciliate-scabrous on the keels, 1% to 2 lines long; lemma 11/2 lines long, 

 gradually narrowed into a capillary awn 2 to 4 lines long, the hairs at base of 

 floret copious, 1 to l 1 /^ lines long. 



Mt. Shasta south through the Sierra Nevada to the San Bernardino Mts. 

 In the mountains from Washington to Wyoming and south to Colorado. 



