MANUAL OF THE GRASSES OF THE UNITED STATES 



363 



7. Muhlenbergia squarrosa (Trin.) Rydb. Mat muhly. (Fig. 

 739.) Perennial from numerous hard creeping rhizomes; culms wiry, 

 nodulose-roughened, erect or decumbent at base, from 5 cm to as 

 much as 60 cm long; ligule 2 to 3 mm long; blades usually involute, 

 1 to 5 cm long, rarely longer; panicle narrow, interrupted, or some- 

 times rather close and spikelike, 2 to 10 cm long; spikelets 2 to 3 mm 

 long, the glumes about half as long, ovate; lemma lanceolate, acute, 

 mucronate. 91 — Dry or moist open often ahvaline soil, New Bruns- 

 wick and Maine to Alberta, south to South Dakota and in the moun- 

 tains to New Mexico, through eastern 

 Washington to California, Arizona, and 

 southern Mexico (fig. 740). The typical 

 form (Vilfa squarrosa Trin. ; Vilfa depau- 

 perata Torr.; Sporobolus depauperatus 

 Scribn., not Muhlenbergia depauperata 

 Scribn.) is rather stout, decumbent or 

 somewhat spreading, Wyoming to Wash- 

 ington and California; a common form 



Figure 737.— Muhlenbergia repens. 

 T'laDt, X 1; glumes and floret, X 10. 

 (Silveus 831, Tex.) 



Figure 738.— Muhlenbergia utilis. Plant, X lj glumes and 

 floret, X 10. (Lindheimer 559, Tex.) 



(Vilfa richardsonis Trin.; Sporobolus richardsonis Merr.) has slender 

 erect culms. These forms intergrade. 



8. Muhlenbergia thurberi Rydb. (Fig. 741.) Perennial, with 

 creeping rhizomes; culms slender, 10 to 20 cm tall, branched at base, 

 the branches erect, tufted, the tufts on branches of the rhizome; 

 sheaths glabrous; blades involute, slender, mostly 1 to 3 cm long; 

 panicle pale, narrow, slender, 3 to 7 cm long, the branches short, 

 appressed, few-flowered; spikelets 3.5 to 4 mm long; glumes a little 



