Pool: THE VEGETATION OF THE SANDHILLS OF NEBRASKA 227 



ance in many localities of a greenish tone which contrasts very dis- 

 tinctly with a background of weathered bunch-grasses. This con- 

 dition occurs long before the appearance of green in the bunch- 



Fig. 11. 'B\a.c'k grzma., Bouteloua hirsuta. Plant, showing habit, 

 a; flowering spikes, b; empty glumes, c; perfect and 

 imperfect flowers, d; flowering glume, e. (From 

 Shantz.) 



grasses. Many of the protected pockets often show a very close 

 cover of this species which affords valuable forage. Associated 

 with this sedge other Carices are common, especially C. pennsyl- 



