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 f Jamacha), south 

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

 pectinata 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 



