MANUAL OF THE GRASSES OF THE UNITED STATES 



519 



13. Bouteloua hirsuta Lag. HAIRY GRAMA. (Fig. 1096.) Peren- 

 nial, densely tufted; culms erect, 20 to 60 cm tall, leafy at base; 

 blades flat or subin volute, about 2 mm wide, flexuous; spikes 1 to 4, 

 usually 2, 2.5 to 3.5 cm long, the rachis extending beyond the spikelets 

 as a slender point 5 to 8 mm long; spikelets 35 to 45, about 5 mm long, 

 second glume tuberculate-hirsute with spreading hairs, the tubercles 

 black; fertile lemma 3-cleft, the divisions and margins of lemma pubes- 

 cent, awn-tipped; rudiment from puberulent to bearded at summit of 



FIGURE 1094. Bouteloua 

 parryi. Panicle, X 1; 

 spikelet, X 5. (Grif- 

 fiths 7277, Ariz.) 



FIGURE 1095. Bouteloua roth- 

 rockii. Panicle, X 1; spikelet, 

 X 5. (Griffiths 7185, Ariz.) 



FIGURE 1096. Bouteloua hirsuta. Pan- 

 icle, X 1; spikelet, X 5. (Griffiths 3371, 

 Ariz.) 



rachilla, cleft nearly to the base, the lobes firm, broad, spreading, the 

 awns black. 21 Plains and rocky hills, Wisconsin and South 

 Dakota to Texas, Colorado, Arizona, and California (Jamacha), south 

 through Mexico; also peninsular Florida (fig. 1097). Bouleloua 

 pectinala Featherly was differentiated from B. hirsuta by taller more 

 robust culms and by a rudimentary spikelet at the end of the rachis. 

 Such a spikelet is rarely developed in B. hirsuta, but it is not corre- 

 lated with robust plants. 



14. Bouteloua gracilis (H.B.K.) Lag. BLUE GRAMA. (Fig. 1098.) 

 Perennial; densely tufted; culms erect, 20 to 50 cm tall, leafy at base; 

 blades flat or loosely involute, 1 to 2 mm wide; spikes usually 2, some- 

 times 1 or 3, rarely more, 2.5 to 5 cm long, falcate-spreading at matu- 

 rity, the rachis not projecting beyond the spikelets ; spikelets numerous, 

 as "many as 80, about 5 mm long; fertile lemma pilose, the awns 

 slender, the intermediate lobes acute; rudiment densely bearded at 

 summit of rachilla joint, cleft to the base, the lobes rounded, the 



