40 



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



Figure 571. — Muhlenbergia arizonica. Plant, X 1; 

 glumes and floret, X 10. (Griffiths 3368, Ariz.) 



illary, flexuous, spreading branches; 

 spikelets about 4 mm. long; glumes 

 equal or subequal, 2 to 2.5 mm. or 

 sometimes as much as 3 mm. long, 

 acute or acuminate, scabrous or pub- 

 escent; lemma 4 mm. long, scabrous, 

 the callus appressed-pilose, the hairs 

 about 1 mm. long, the delicate capil- 

 lary awn 10 to 35 mm. long. Qi 

 — Canyons and rocky slopes, south- 

 ern Arizona. 



57. Muhlenbergia metcalfei Jones. 

 (Fig. 576.) Perennial, in close tufts; 

 culms erect, 50 to 80 cm. tall; ligule 



3 to 15 mm. long, sometimes longer; 

 blades involute, slender, flexuous, 

 scabrous, sometimes only slightly so, 

 not crowded at base; panicle narrow 

 but somewhat loose, pale or slightly 

 purplish, 15 to 40 cm. long, the 

 branches usually naked at base; 

 spikelets tapering to summit, about 



4 mm. long; glumes nearly equal, 

 obtuse, a little less than half as long 

 as spikelet; lemma scaberulous to- 

 ward summit, the awn 3 to 10 mm. 

 long. % — Rocky hills, Texas and 

 New Mexico. 



58. Muhlenbergia dubia Fourn. 

 Pine muhly. (Fig. 577.) Perennial, 

 closely tufted; culms erect, hard and 

 wiry at base, 30 to 100 cm. tall; 

 sheaths with erect firm auricles, 4 to 

 10 mm. long, rarely longer; blades 

 involute, scabrous; panicle narrow, 

 sometimes almost spikelike, grayish, 

 10 to 30 cm. long, rarely longer; 

 spikelets about 4 mm. long; glumes 

 about half as long as the spikelet, 

 minutely scaberulous, obtuse; lemma 

 minutely scaberulous, with an awn 

 as much as 4 mm. long, rarely acu- 

 minate only. % (M. acuminata 

 Vasey; Sporobolus ligulatus Vasey 

 and Dewey.) — Canyons and rocky 

 hills, up to 7,000 feet elevation, west- 

 ern Texas, New Mexico, and northern 

 Mexico. 



59. Muhlenbergia dubioides C. 0. 

 Goodding. (Fig. 578.) Culms 50 to 

 100 cm. tall, densely tufted, erect; 



Figure 572. — Muhlenbergia torreyi. Plant, X 1; glumes 

 and floret, X 10. (Chase 5298, Colo.) 



