117 



Fig. 111. MUHLENBERGIA GRACILIS Trin. Unifl. 193. 1824.— A slender 

 but rather rigid, densely csespitose perennial 1.5-6 dm. (6'-24') high, with nar- 

 row, involute, rigid leaves and contracted panicles 8-15 cm. (3'-6') long. 

 Spikelets 3-4 mm. (li"-2") long; empty glumes (a, 5) nearly equal in length, 

 the first about one-half as long as the flowering glume, 1-nerved, acute, or erose 

 at apex, the second a little longer than the first, 3-nerved and 3-toothed, rarely 

 entire at apex; flowering glume (c, d) pubescent or scabrous on the back, ciliate 

 on the margins; awn flexuose 8-16 mm. .(4"-8") long.— Ascending to 2,700 m. 

 (8,800°) or more, Texas to Arizona, Colorado, and Wyoming. (Mexico.) June 

 to September. A much reduced form 15-30 cm. (6'-12') high, with awns 2-4 

 mm. (l"-2") long is var. breviaristata Vasey, Contr. U. S. Nat. Herb. 3 : 67. 

 1892. 



