400 



Figuee 565. — Muhlenbergia fib'culmis. Panicle, X 1; 

 glumes and floret, X 10. (Type.) 



MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



rocky soil, 2,000 to 3,000 m. altitude, 

 Wyoming, Colorado, New Mexico, 

 and Utah. 



47. Muhlenbergia virescens (H. B. 



K.) Kunth. Screwleaf MUHLY. (Fig. 

 566.) Perennial; culms densely tufted, 

 erect, 40 to 60 cm. tall, the old basal 

 sheaths flattened and more or less 

 coiled; ligule, except the margin, deli- 

 cate, 3 to 10 mm. long; blades flat or 

 those of the innovations involute, 

 mostly elongate and flexuous; panicle 

 narrow but rather loose, 5 to 15 cm. 

 long, the branches erect; spikelets, 

 excluding awns, about 5 mm. long, 

 the glumes slightly shorter, acute, the 

 second 3-nerved; lemma and palea 

 pubescent on the lower half, the lem- 

 ma tapering into a slender flexuous 

 awn 1 to 2 cm. long. % — Can- 

 yons, rocky hills, and mesas, New 

 Mexico and Arizona to central Mex- 

 ico. 



48. Muhlenbergia monticolaBuckl. 

 Mesa mtjhly. (Fig. 567.) Perennial; 

 culms tufted, slender, erect or de- 

 cumbent at base, 30 to 50 cm. tall, 

 branching at the lower and middle 

 nodes, leafy throughout; blades 3 to 

 7 cm. long, narrow, flat, or soon 

 involute; panicle soft, narrow, con- 

 tracted, 5 to 10, sometimes to 20 

 cm. long, the branches appressed or 

 slightly spreading; spikelets, exclud- 

 ing awns, about 3 mm. long, the 

 glumes about two-thirds as long, 

 subacute to obtuse and erose at tip; 

 lemma pubescent at base and on 

 lower half of margin, tapering into 

 a delicate flexuous awn 1 to 2 cm. 

 long. % — Rocky hills and can- 

 yons, western Texas to Arizona and 

 central Mexico. 



49. Muhlenbergia parviglumis 

 Vasey. (Fig. 568.) Perennial, with 

 the habit of M. monticola; blades on 

 the average somewhat longer, 1 to 

 3 mm. wide; panicle looser, the 

 branches filiform, longer; glumes mi- 

 nute, erose, subacute to truncate; 

 lemma scaberulous only, tapering in- 



Figure 566. — Muhlenbergia virescens. Plant, X 1; 

 glumes and floret, X 10. (Palmer 565, Ariz.) 



