420 POACE^. 



culms involute, bristle-pointed, 2-5 cm. long, those of the sterile 

 shoots rather shorter. Spikes 4-6 in number, more or less curved, 

 1.5-2.5 cm. long. First glume hyaline, bristle-jiointed, 2-2.5 mm. 

 long, second linear, about 3 mm. long, 2-toothed, pubescent on the 

 keel, the seta 1-2 mm. long; floral glume pubescent on the back, 

 oval, 2.5-3 mm, long, 2-lobed, lateral and central set^e reacliing to 

 the same height 1-2 mm. above the glume; palea linear to oval, 

 2.2-3 mm. long, 4-toothed with 2 short setse, the pedicelled rudi- 

 ment bearing 3 equal bristles about 2.5 mm. long. 



Mexico, Parry S Palmer 943|-, Palmer 1357, Pringle 413; 

 Arizona, Xealley. 



Apparently confined to sandy alluvium of mountain streams. 



9. B. breviseta Vasey, Contrib. U. S. Nat. Herb. 1 : 58 (1890). 

 A tufted more or less glaucous and rather slender perennial, 



25-35 cm. high, from stout creeping rootstocks. Culms hard, with 

 no cavity. Sheaths 6-11 in number, mostly a little longer than the 

 internodes; ligule a mere ring, slightly ciliate; blades rigid, invo- 

 lute, 2-6 cm. long, 0.5-0.7 mm. diam. Spikes mostly in twos, 

 sometimes single, 2-3 cm. long, about 3 mm. diam. Spikelets 

 crowded, empty glumes lanceolate, 1-nerved, first 3 mm. long, 

 second 4 mm. long; floral glume of lower floret oval, 3 mm. long, 

 3-nerved, setae equal, about 1 mm. long; palea incurved, oval; 

 second floret 1.5 mm. long with hairs of the same length, the awns 

 2.5-3 mm. long. 



Texas, NeaUey in 1889. 



10. B. Rothrockii Yasey, Contrib. U. S. Nat. Herb. 1 : 268 

 (1893). B. polyslacliya var. major Vasey, U. S. Geog. Surv. by 

 Wheeler, 6:287 (1878). 



Culms 40-60 cm. high, racemose, usually bearing 5-7 spikes 

 2.5-3 cm. long, sessile, about 2.5 cm. distant. Leaf -blades flat, 6-10 

 cm. long, scabrous above. Empty glumes hyaline, glabrous, oblong, 

 1-nerved, mucronate or short-awned, lobed or with lateral teeth, 

 first glume 1.5 mm. long, second 2.5 mm. long; floral glume ovate 

 in outline, hairy near the base and on the margins, about 3 mm. 

 long, 1.5 mm. wide, 4-lobed with 3 setae, lateral ones slightly long- 



