420 1H)A('E.15. 



culms involuti', bristU'-poiiitt'd. )i-i^> cm. loii":, those of tlu' sti-rilo 

 shoots rather sliorler. S[)ikos 4-t) in luimbi'r, more or k'ss curveil, 

 1.5-2.5 cm. loui;^. First ghimc hviiliiu', bristk'-poiiittHl, "^-'J..*) mm. 

 \o\\g, sccoml linear, about 3 mm. louj;, ^-tootheil, pubescent on the 

 keel, the seta 1-2 mm. lonj;; lloral tflume pubescent on the back, 

 oval. 2.5-3 mm. lontr. 2-lobed, lateral and central seta? reaching' to 

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

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

 ment bearing 3 equal bristles about 2.."» mm. long. 



Mexico. I^arnj if Pahuvr •.•43^. /" '>*')' 1351. Pvimjh 413; 

 Arizona. yvaUeii. 



A{)parently confined to sandy alluvium of mountain streams. 



it. B. breviseta \'as(>y. ("ontrih. l'. S. Nat. Herb. 1:5S(181M)). 



A tufted more or less glaucous and rather slender perennial. 

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

 no cavity. Sheaths O-ll in lunnber. mostly a little longer than the 

 internodes; ligiUe a nu're ring, slightly ciliate: l)lades rigid, invo- 

 lute. 2-(> 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; lloral glume of lower lloret oval. 3 mm. long, 

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

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

 2.5-3 mm. long. 



Texas, XcaUi'ij in ISSl). 



10. B. Rothrockii Vasey, t'ontrib. V. S. Xat. Herb. 1:208 

 (ISiio). Ji. p()Ii/iif(ic/ii/(( var. major \'asey, U. S. (Jeog. Surv. by 

 Wheeler, 6:28: (1818). 



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

 2.5-3 cm. long, sessile, about 2.5 cm. ilistaut. Leaf-blades flat. 0-iO 

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

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

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

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

 long, 1.5 mm. wide, 4-lobed with 3 set^^j, lateral ones slightly long- 



