82 THE AGRICULTUEAL GRASSES OF THE UNITED STATES. 



BouTELOUA OLIGOSTACHYA. (Mesquite grass, Gramma grass, Buffalo 



grass.) 

 This is a perennial species growing on the great plains from Montana 

 and Dakota southward to Texas. The culms are from one-half to 1^ feet 

 high, i^ear the top there are usually two or three, sometimes more, 

 curved flowering spikes, about 1^ inches long ; the culm and leaves are 

 smooth ; the outer glumes and the flowering glumes are sparingly soft- 

 hairy, the lobes awl pointed, the sterile flower or rudiment is copiously 

 villous- tufted at the summit of the naked pedicel, its three awns equal- 

 ing the perfect flower. (Plate 77.) 



BouTELOUA HiRSUTA. (Bristly mesquite or Gramma grass.) 



This annual or biennial species has about the same range as the pre- 

 ceding, is of about the same size and general appearance. The upper 

 empty glume is on the back hispid with bristly hairs proceeding from 

 dark, warty glands ; the flowering glume is pubescent, three-cleft into 

 awl-pointed lobes ; the sterile flower and its pedicel are glabrous, the 

 three sterile awns longer than the fertile flower. 



BouTELOUA POLYSTACHYA. (Low Gramma grass.) 



This species probably does not reach farther north than northern New 

 Mexico. It is an annual from 6 to 10 inches high growing in clumps 5 the 

 culms are slender, branching and bent at the lower joints. The culin 

 terminates in a raceme-like panicle, 3 to G inches long, composed of five 

 to seven alternate, narrow, one-sided spikes, which are about 1 inch long 

 and one-half inch to 1 inch apart. The spikelets are generally close but 

 not so dense as in the preceding, and much smaller ; the outer glumes 

 are thin, unequal, oblong, the upper one about one line long, bifid and 

 mucronate pointed; the flowering glume of the perfect flower is oblong, 

 obtuse, three-nerved, the nerves extended beyond the glumes into short 

 awns, with two broad lobes, one on each side of the central awn, and 

 two shall lateral lobes, one on the outer side of each lateral awn, the 

 outer margins ciliate. The rudimentary flower is very short stalked, 

 with three small glume-like scales and three short awns. There are 

 several varieties or forms of this species, some smaller and some larger. 

 It abounds near the banks of streams and furnishes excellent pasturage. 

 (Plate 78.) 



BouTELOUA RACEMOSA, {B. curtipendula, Gray). (Tall Gramma 



grass.) 

 This species ranges from Mexico to British America, and east of the 

 Mississippi Eiver in Wisconsin and Illinois. It is easily distinguished 

 from the others by its taller growth, and by the long, slender raceme of 

 twenty to fifty or more slender spikes. These are usually about half an 

 inch long and reflexed. There are from six to ten spikelets on each 

 spike. The outer glumes are lanceolate, acuminate ; the upper about 

 two lines long and scabrous ; the flowering glume is oblong, between 



